ABSTRACT. The Messara Basin, a critical agricultural and hydrogeological region in Crete, Greece, faces escalating geohazards, including land subsidence driven by excessive groundwater exploitation. This study combines data from the European Ground Motion Service (EGMS) with field inspections of 86 Persistent Scatterers to investigate the spatial and temporal dynamics of subsidence phenomena. Site inspections confirm significant vertical displacements, with EGMS data showing mean velocities ranging from +10.4 mm/year to -31.2 mm/year and cumulative vertical displacements reaching -150 mm in affected areas. Groundwater levels from 2021 and 2023 exhibit seasonal fluctuations of up to 120 m and extensive cones of depression, with levels dropping as low as -50 m below sea level. Deformations are particularly pronounced in Quaternary and Pleistocene deposits, where unconsolidated sediments and marine terraces demonstrate high susceptibility to structural instability. These findings highlight the importance of integrating remote sensing technologies with field surveys to identify and address geohazards effectively. The results underscore the urgent need for sustainable groundwater management practices to mitigate environmental risks and ensure the long-term stability of the basin's hydrological and agricultural systems.

ABSTRACT. This work aims to develop a constantly updated flood hazard assessment tool that utilizes readily available datasets derived by remote sensing techniques. It is based on the recently released global land use/land cover (LULC) dataset Dynamic World, which is readily available as an open data source within Google Earth Engine platform. The tool is updated constantly following the release rate of Sentinel-2 images, i.e., every 2 to 5 days depending on the location and provides a near real time detection of flooded areas. Specifically, it identifies how many times each 10 m pixel is characterized as flooded for a selected time period. In order to investigate the fruitfulness of the proposed tool, we compared the outcome of the tool against the Regional Flood Hazard Maps developed in the frames of the EU Water Framework Directive, and we found several inconsistencies of the two approaches. The innovative character of the presented methodology consists of the use remotely sensed-based datasets, becoming available at increasing rates, for developing an operational instrument which defines and updates the flood hazard zones in real-time required.

ABSTRACT. Managing volcanic risk encompasses a multifaceted and crucial field, aimed at reducing the hazards posed by volcanic eruptions to human life, infrastructure, and the surrounding environment. This endeavor includes preparedness planning, monitoring, and responsive actions, with continuous monitoring of volcanic activity using state-of-the-art technology and geophysical tools being the first and most essential step (Katsigera et al., 2024). SANTORY is a state-of-the-art project aiming at submarine volcanic hazard monitoring in the Aegean Sea. Focused on the Kolumbo submarine volcano NE of Santorini Island, this cutting-edge observatory combines advanced imaging, geophysical and geochemical measurements, and real-time monitoring technologies to address one of the region’s most important volcanic threats (Nomikou et al., 2022). For the operation of the observatory, there were conducted three oceanographic cruises, during which specialized scientific instruments were installed inside the crater for several months (Figure 1), later retrieved to collect data, and subsequently re-deployed. These instruments included: the SANTORY underwater observatory, which comprised sensors for collecting acoustic data, temperature (T°C), CO2, H2S, O2, pressure, electrical conductivity (EC), pH, and turbidity; inclinometers for measuring marine currents within the crater; specialized thermometers for monitoring temperature changes in the polymetallic chimneys of the hydrothermal field; optical cameras positioned in front of active polymetallic chimneys to record hydrothermal fluid flow; and advanced underwater recording stations for measuring physical parameters in water, such as turbidity, temperature, conductivity, pressure, and oxygen levels. Additionally, the ROV was equipped with the following instruments for real-time data collection: a multispectral and stereo camera (“THEIA”) for capturing the texture of the seafloor with multispectral data; the gSniffer device for real-time γ-radiation measurements; the γ-radiation imager (“SUGI”) for real-time γ-radiation imaging; and a UV camera (“CHERI”) for detecting Cherenkov radiation, marking a global first in underwater applications (Figure 2). Over the past two years, SANTORY has provided unprecedented insights into Kolumbo’s geological dynamics and volcanic activity. High-resolution 3D mapping revealed steep slopes, mass-wasting deposits, and hydrothermal vent fields, critical for assessing seafloor instability and potential eruption risks. Novel hyperspectral imaging and autonomous video systems have captured persistent vent activity, bubbling plumes, and environmental changes, thus providing the most complete assessment of hydrothermal processes to date and establishing a baseline for potential tracking of underlying volcanic processes. Autonomous sensors deployed on the crater floor have been monitoring hydrothermal outflow temperature, pressure, and chemistry of fluids; these parameters will help quantify chemical fluxes, and reveal periodic variations driven by tides, in addition to magmatic activity. Datasets revealing these hydrothermal fluctuations may thus be critical in detecting precursors signals of volcanic unrest (e.g., changes in subsurface permeability, magmatic degassing). Chemical and isotopic analyses of hydrothermal fluids have revealed the degassing of CO2-rich fluids characterized by a mantle-like 3He/4He signature. These findings highlight Kolumbo’s potential for hazardous eruptions and its classification as a high-risk volcanic system. Through the program, innovative results emerged, highlighting the uniqueness of the Kolumbo submarine volcano. Acoustic data collected every 30 minutes included one-minute recordings that revealed local hydrothermal events and bubble activity related to CO2 release in the 4000-8000 Hz range (Figure 3). Algorithms were developed to differentiate hydrothermal noise from environmental background noise, identifying bubble radii primarily in the range of 0.20-0.54 mm. Persistent and active bubble activity was observed within the hydrothermal field, with high temperature recordings (232°C) inside hydrothermal chimneys. Local hydrothermal events and fluid dynamics were identified, showing synchronized variations and anomalies in current meters, significant cooling phenomena, and high-velocity currents regulated by tidal forces. Geochemical analysis confirmed acidic and slightly reducing conditions on the crater floor, helium isotopic composition indicating mixing of atmospheric and magmatic sources, and high concentrations of mercury (Hg) and methylmercury (MeHg) pointing to potential natural pollution. CO2 concentrations were extremely high (96%). Water samples collected at various depths showed anomalies in magmatic/geothermal gases, while trace elements such as Mn, Cs, and Hg exhibited significant deviations. A pH decrease above active chimneys was observed between December 2022 and October 2023, with the lowest value recorded during the last expedition (pH=5.33; 10/2023). For the first time, natural radioactivity data were recorded within the Kolumbo hydrothermal field. The typical radioactivity measurement rate away from the seafloor and known hydrothermal fields is around 1–2 counts per second. In contrast, radioactivity near the hydrothermal chimneys of Kolumbo reaches an impressive level, approximately three orders of magnitude higher, with a maximum of 996 counts per second (Figure 4). Additionally, isolation of microorganisms from Kolumbo's extreme environment was achieved, where these microorganisms are of particular interest for biotechnological applications as they possess unique mechanisms for adapting to extreme conditions. Microbial data also unveiled diverse communities thriving in hydrothermal vent systems, offering insights into their metabolic pathways and resilience mechanisms. Metagenomic analyses uncovered new information about the carbon and methane cycles, which directly impact our planet's climate. The project results provide valuable information for assessing volcanic hazards, contributing to the protection of the region from natural disasters, safeguarding human lives, and supporting the local economy. SANTORY is more than a research project—it is an initiative for developing a protocol for volcanic hazard mitigation that can be extrapolated to other submarine systems. By integrating cutting-edge technologies and multidisciplinary expertise, the project delivers actionable insights to improve early warning systems and protect vulnerable coastal communities. SANTORY sets a new benchmark in safeguarding against submarine volcanic threats. All scientific data are accessible through the SANTORY Open Data Hub platform, available to both the residents of the Municipality of Thira and the scientific community. https://santory-open-data-hub-nom.hub.arcgis.com/

ABSTRACT. The area offshore the central Ionian Islands (Cephalonia, Lefkada, Zakynthos, and Ithaca), western Greece (Fig. 1A), is in the Mediterranean regions one with the highest seismic activity and tsunamigenic potential (Fig. 1, C). Here, the Hellenic frontal thrust system stops against the right-lateral Cephalonia Transform Fault, a fault more than 100 km-long (Louvari et al. 1999), to step back towards Corfu (Sachpazi et al., 2000). In recent decades, this area experienced several destructive events, such as the 1953 Cephalonia earthquakes (three M6+ events) and the more recent the Mw 6.8 Zakynthos event occurred the 28 October 2018 (Ganas et al., 2020) and the swarm of moderate size events ranging from 5.3 to 5.7 occurred in 2006 (Papadimitriou et al. 2012). Although this area has a high exposure to geological risk, Offshore remains little explored. In order to improve the knowledge on shallow deformation, fault geometry and on the hazard potential of tsunamigenic faults, we carried out two oceanographic cruises, in May 2022 (aboard of the R/V G. Dallaporta supported by the Italian National Research Council - CNR) and in June 2023 (aboard of the R/V L. Bassi from the National Institute of Oceanography and Applied Geophysics - OGS in the frame of the POSEIDON project supported by the Eurofleet+ Program). During these two cruises we collected a multidisciplinary and multiscale dataset composed of geophysical (e.g., bathymetry, multichannel seismic data, magnetometry) and geological data (gravity cores). The new geophysical data, including high-resolution and high-penetration multichannel seismic data and high-resolution swath bathymetry, allowed us to map the anatomy of the Cephalonia Transform Fault system in its southern sector and deformation affecting the slope to south of Zakybthos. We studied the sediment deformation patterns at the intersection between the Cephalonia strike-slip fault and the thrust fronts of the Hellenic System revealing a larger system and more complex structure than anticipated from previous works. The main outcome of the present work is a new morpho-structural map of the Cephalonia and Zakynthos offshore. South of Cephalonia Island, the CTF “widens” to a 25 km-wide system of splays composed of elongated sigmoidal, positive-flower structures, possibly merging at depth into a single strike-slip fault. To west of Cephalonia Island, CTF narrows into a 6 km-wide strike-slip structure. Our data support a dominant strike-slip kinematic with compressive component of the CTF. South of Zakynthos, the tectonic regime in the shallow sediments is dominated by extension, possibly representing a secondary tectonic system controlled by a local extensional stress field associated with a gravitational instability.

ABSTRACT. It is well documented that only preparedness and prevention can support modern communities in respect to the earthquake risk. Being one of the most seismic prone areas in the world, Greece has invested a lot in the prevention of the impacts of future earthquakes and in the increase of preparedness of the structured and non-structured elements of our societies. Prevention is achieved through interventions and actions aiming at the identification of hazard zones, minimizing the exposures on the build environment and developing plans and regulations to manage crises. In most cases preparedness is achieved by strengthening and improving the behavior of material elements and infrastructures, the increase of knowledge regarding the hazard and its impact, as well as the improvement of the self-protection of citizens. In the past years, repeated Earthquake crises revealed that further improvements both on prevention and preparedness are necessary which can be made only if assessment of past crises’ management is performed. The earthquake of Arkalochori in central Crete is of one the most recent and most peculiar crises in Greece. The foreshock sequence started on the beginning of June 2021, just at the end of the COVID 19 crisis, and lasted almost three months having one strong earthquake of 4,8 R on July 24. The long foreshock period enabled the establishment of many seismic instruments in the broader area to monitor the phenomenon. The main shock took place early in the morning on September 21st, 2021 with a magnitude of 6 R scale and focal point 10 kms below the town of Arkalochori (Ganas et al. 2021). The earthquake took place along a well-known active fault in the area, the Kasteli fault (Fassoulas 2001) that has produced a swam of small eq in 1995 too (Delibasis et al. 1999). The town, that is one of the largest of rural Crete with a population of about 4000 inhabitants and many nearby villages were seriously affected with collapses and damages of old and more recent constructions, while even the city of Heraklion experienced moderate intensities with minor impacts. This was the first strong earthquake onshore Crete for more than a century (Papadopoulos 2011), and fortunately, there was only one human victim that was killed by a strong aftershock that happened few hours after the main event. The most peculiar feature of this crisis was though the very long aftershock period that lasted almost a year with several events between 4 and 5 R scale. It was estimated that more than 4750 earthquakes took place on the broader area over a period of one year (Vallianatos et al. 2022) challenging the structural behavior of the buildings and the mental health of local population. The response of the Civil Protection mechanism was immediate with first responders and civil protection volunteers taking action soon after the main shock installing temporary camps at the Arkalochori and several other villages, and a more organized shelter at the Exhibition Center of Arkalochori few days after. The response of the local population was remarkable with hundreds of them arriving at Arkalochori from the first day to support the victims. This huge offer of volunteers created problems till a mechanism to manage them was set, but their contribution in compensating the burden of the local people and supporting their daily needs was invaluable even months after the earthquake. The total toll of impacts counts more than 7000 houses heavily damaged by the main shock and its aftershocks with about 3900 of them to be demolished. Within these structures occur many local schools and churches. Apart from the first financial support that state provided soon after the earthquake to those affected by, the recovery process according to the locals failed totally to cover the needs of local societies (p.c. K. Gantatsios, president of “Elpis” the association of the victims of the earthquake 2024). Three years after the earthquake many families still live at preconstructed houses at the temporary shelter, from the 7000 applications for financial aid to repair houses that have been submitted only few tens have been elaborated by the relative services and the broader area presents images of abandonment and depopulation that was obvious at the recent census. It is important to mention that the psychological burden of the local communities was not only increased by the long-lasting aftershocks but also from rumors and fake news that were circulated at social media but even the national broadcasting channels. The Arkalochori earthquake is a case study under RESILIAGE project funded by the Horizon Europe program and coordinated by the Polytechnic of Torino, in which the University of Crete is among the 18 partners that aim to build sustainable resilient communities with local heritage drivers (https://resiliage.eu/). The main objectives of the project are thus focused on understanding citizen reaction in case of crisis, on cocreating new knowledge encompassing the local heritage drivers that make communities stronger and new tools that provide more accurate information and make it accessible through easy-to-use tools and finally, lightweighting solutions to support first responders and empower citizens in crisis and disaster situations. The project has defined five Systemic Resilience Innovation (SyRI) frameworks focusing on Adaptive Governance, Health and Wellbeing, Active Memory, Social Interaction and Inclusiveness and Socio-economic Resilience that are examined in five European territories facing variable risks. The Region of Crete is one of them addressed to the Active Memory in respect to the earthquake risk. Hereby we present the results of two workshops that have been developed in Crete under RESILIAGE in order to assess the management of Arkalochori EQ crisis, to identify the cultural factors that may influence local resilience, to build local networks through synergies and collaborative actions, and to identify the gaps in the management crisis operation in order to develop proposals for future improvement.

ABSTRACT. In this contribution, we demonstrate the operational status of a new GNSS infrastructure in the western Gulf of Corinth (Greece) that is based on the collaboration of a multidisciplinary research team and on low-cost equipment. Our low-cost instrumentation includes a multi-GNSS dual-frequency chip (Ublox ZED F9P module) mounted on a Raspberry-Pi 4 compute module IO board together with an industry-standard MEMS accelerometer. It provides signal tracking for multi-GNSS systems (GPS, GLONASS, Galileo and BeiDou). The GNSS data are collected 24/7/365, quality-checked and processed by use of the PRIDE-AR open-source software. The E, N, Up velocities for two sites (GEDP & KRHN) were estimated on the IGS20 reference frame. We tested our results against the velocities of neighbouring permanent GNSS stations with overall good agreement.

ABSTRACT. The four active volcanic centres of the Aegean arc and another ten inactive volcanic centres, activated during Oligocene – Middle Pleistocene, following its southward migration are described with emphasis on their tectonic signature. They are all localized within tectonic grabens, resulting from the back-arc extension of the Hellenic arc throughout its Late Eocene – Present evolution. Our study was based on geological maps and the transverse tectonic profiles both onshore and offshore. The material presented is either from our own publications (usually modified) or new. The orientation of the tectonic grabens depends on the extensional stress field of each period and region. The existence of Late Miocene granitic rocks in the Cyclades without outcrops of Late Miocene volcanics is probably due to the considerable uplift of the Cycladic metamorphic core complex that has denudated the upper geological formations together with the volcanic rocks. The volcanic activity is observed within the arc parallel marine molasse of the North Aegean – Rhodope back arc basin during Oligocene – Early Miocene and within the Plio-Quaternary marine arc parallel tectonic grabens/basins of the South Aegean. Middle-Late Miocene volcanic rocks are observed within continental tectonic grabens/basins only in the lateral margins of the Cycladic metamorphic tectonic window.

ABSTRACT. Abstract The western border of the Serbo-Macedonian massif with Circum-Rhodope belt has been a subject of discussion in the past. Several questions have been raised about the geological structure of the study area (ΝΕ part of Thessaloniki, Pefka, Filiro, Asvestochori), based on variations in structural and lithological characteristics. Field – structural and lithological data were initially collected and then the geological structure and the tectonostratigraphy of the study area were visualised. In the area of interest there are characteristic rocks of both continental and oceanic crust in contact, as a result of past tectonic events (D1-D6 deformation events). Older tectonic events of compressive ductile stress regime (D1-D2) are correlated with the tectonic emplacement of ophiolites and the general terrane accretion, whine newer ones of brittle stress regime (D4-D5) are related with the thrusting and the creation of tectonic slices, as well as the inversion of the whole series. The lithological units of the area have been inverted by these tectonic events (D4-D5). As a result, the older rocks are placed tectonically on top of the younger ones. Compression forces have created a fold-and-thrust belt with a sense of movement to-the-SW. A lithological unit belonging to the Serbo-Macedonian massif is tectonically emplaced between the lithological units of Circum-Rhodope belt. The geological basement in the study area is of Serbo-Macedonian origin and the tectonic movement of the tectonic slices was done upon this basement.

ABSTRACT. Research Highlights High-pressure (HP) marbles in the Cycladic Massif bear a columnar-shaped calcite microstructure that represents a powerful marker of deformation. Detailed structural analysis of the columnar calcite microstructure can further refine our knowledge about the exhumation processes of HP terranes.

ABSTRACT. The Argolic-Arcadian Border range is built up by rocks of the Tripolitza and the Pindos Zone. Its tectonic architecture is deeply exposed in the area of the Xerias Window. Key structures are worked out in this article. The nappe-shaped superposition of the Tripolitza Zone by the Pindos Zone is obvious in the frame of the Xerias Window. The vergence of the key structures of the latter varies everywhere between W and SW, which proves a relative transport of the Pindos Zone as a whole in that direction. In contrast, the Tripolitza Zone doesn’t show evidence for such a transport. After finishing the nappe transport both Pindos and Tripolitza Zone experienced further, collective deformations, which are brought in a probable chronological order. Round about since Upper Miocene, the compressive stress of the Hellenides was followed by young extensional tectonics, which continues until today. Its influence on the development of the window and on the forming of its frame is described. The most important faults that can be related to the spreading tectonics are called within this investigation as Xerias Faults. Finally, the impacts of the strong regressive erosion, of the numerous landslides, and of the widespread slope waste on exposing resp. covering the tectonic elements are regarded.

ABSTRACT. Gulf of Corint is a rift structure in Greece with asymmetric evolution on the northern and southern side. There are significant normal faults on the southern bank dipping to North. The basement is covered by soft young sediments with conglomerates and clays prevailing. Target of gravity mapping was to constrain existing geological models using gravity/density modelling. It was found that in some places, especially between Helike and Pirgaki faults the structural composition may differ significantly. The assumed thick block of conglomerates was reduced to small thickness according to the new model. Most likely the uplift was higher and the block was strongly eroded. The study demonstrates the profit of using geophysics during geological mapping.

ABSTRACT. The Water Framework Directive requires the establishment of monitoring programmes covering groundwater quantitative status, chemical status and the assessment of significant, long-term pollutant trends resulting from human activity. Greece has a significant disadvantage in developing such a monitoring programme because of its geological complexity. This disadvantage is further magnified by the obligatory choice of Greece, due to lack of data, to delineate «Groundwater Systems» and not «Groundwater Bodies» as Guidance Documents describes. The basic principles that Guidance Documents suggest are not followed by the developed monitoring network in the region of the Peloponnese. There are fewer than the necessary number of monitoring sites, which are badly distributed over the area and, in many cases, not representative of the monitored aquifers. In contrast to the particularly costly and time-consuming solution of developing an adequate and representative ground water monitoring network, the alteration of all existing wells/boreholes to monitoring sites by establishing of institution of “Well Inspector” seems to be the only direct and sustainable solution to the problem.

ABSTRACT. This study focuses on the hydrogeological and hydrochemical characteristics of the Selinous basin region, located in northwest Peloponnese, Greece. The research aims to understand the influence of geological formations, land use, and human activities on the hydrochemical properties of both surface water and groundwater in this karst region. The investigation involves the collection and analysis of 40 water samples from wells, surface water, and springs, examining major and trace elements to evaluate water quality and hydrological processes. The results highlight the significant role of rock weathering, particularly carbonate and silicate weathering, in controlling the hydrochemical evolution of the river basin. The study also emphasizes the importance of comprehensive hydrochemical analyses for effective water resource management in karst aquifers, which are highly vulnerable to contamination due to their unique hydrological characteristics.

ABSTRACT. This study investigates groundwater quality and seasonal dynamics in the Chortiatis region of northern Greece to provide insights for sustainable resource management. A combination of hydrochemical analyses and monthly groundwater level measurements was employed to evaluate the region's complex aquifer systems influenced by diverse geological formations and human activities. Hydrochemical data reveal that groundwater predominantly belongs to the Ca-HCO₃ type, with notable ion exchange processes and potential pollution sources such as agricultural and urban activities. Trace element concentrations, including elevated levels of iron (Fe) and manganese (Mn), highlight interactions with mineralized rock layers and possible contamination risks. Seasonal groundwater level variations exhibit distinct recharge patterns driven by precipitation events, with significant declines during dry periods. Spatial heterogeneity among monitoring wells reflects variations in recharge capacity and aquifer exploitation intensity. These findings contribute to understanding the hydrogeological framework and offer essential data for effective groundwater management, pollution mitigation, and the development of sustainable resource strategies in the region.

ABSTRACT. SAMY II project is carried out by Hellenic Survey of Geology and Mineral Exploration (H.S.G.M.E.) Project main activities in Greek Territory are: a) borehole inventory by recording drilling technical data and on-line measurements, b) database production based to all recorded data and c) groundwater abstraction related to groundwater resources in ground water bodies. During inventory field work, recording data concerns geographical coordinates, drilling operational status and borehole technical characteristics (depth, diameter drill hole and pipeline, pump type). Also, borehole usage such as irrigation, drinking water, stock farming are basic features of recording data with details of pumping. Based on inventory data final reports are drawn up for all Ground Water Systems in the field area including also geomorphological, geological, hydrogeological conditions, land use area, statistics with processing of all recording raw data, drawing water estimation and aquifer water balance. The result of the inventory program with the systematic counting of boreholes in all of the Ground Water Systems (GWS) and the recording of the extractable quantities of water, contributed to the effective implementation of the Water Framework Directive 60/2000, but also to the formulation, implementation and control of policies (water saving, programs of measures, etc.) concerning the rational management of water resources.

ABSTRACT. The groundwater system of Larissos has poor chemical status due to human activities in the area. Due to the high-water needs of the population, aquifers have been underused for many years and have degraded the quality and quantity of groundwater.The study area is located in northwestern Peloponnese, and specifically in the prefecture of Achaia, and occupies an area of approximately 163 km2. The main river in the study area is the Larissos river. The main riverbed of Larissos is 19,5 km long, originating from mountain Movri and emptying into the Prokopou lagoon.

ABSTRACT. The Petrified Forest of Lesvos is a unique natural monument located in the western part of Lesvos Island, Greece. It was formed during the Lower Miocene due to intense volcanic activity in the North Eastern Aegean region. The Lesvos Petrified Forest was declared a protected natural monument in 1985, and its protected area covers 15,000 hectares. In 2000, it became one of the first four European Geoparks. In 2004, it was a founding member of the Global Geoparks Network. Lesvos Island was designated a UNESCO Global Geopark in 2015 by the UNESCO General Conference. The Lesvos Petrified Forest is the primary geological heritage feature of international significance that led to the recognition of Lesvos Island as a UNESCO Global Geopark. Furthermore, it was recognized as one of the first 100 IUGS geological heritage sites by the International Union of Geological Sciences. Thus, the Lesvos Petrified Forest is one of the most important geological heritage sites for research, education, tourism, and sustainable development. During the last decade, the new road connecting Kalloni with Sigri was constructed, traversing the western peninsula of Lesvos and specifically the protected area of the Lesvos Petrified Forest. During road construction, a large number of remarkable fossil sites with impressive fossilized tree trunks were unearthed, located along the roadside. Consequently, twelve fossiliferous localities along the Kalloni-Sigri road now constitute an open-air park, offering visitors a unique experience within the Lesvos Petrified Forest.

ABSTRACT. Communities of West Macedonia have intensified their efforts to preserve and revitalize the characteristic stone architecture and related customs of the Mastorohoria, and the structures which the stone masons constructed across the region. In parallel, Grevena-Kozani UNESCO Global Geopark aims to preserve and promote its geoheritage in the form of recognized geosites, tangible and intangible cultural heritage. Several events of the past year, which were cooperative efforts between the geopark, communities and government, constitute vital steps toward the conservation of this endangered craft.

ABSTRACT. This study presents an innovative multiscale 3D mapping and geovisualization approach for the Ioannis Toumpelekis Park, part of the Lesvos Petrified Forest in Greece, utilizing unmanned aerial vehicle (UAV) technology. The Petrified Forest of Lesvos, a UNESCO Global Geopark, preserves fossilized tree trunks and provides valuable insights into the region's paleoenvironmental and geological history. By employing UAVs for high-resolution data acquisition, photogrammetric techniques, and immersive geovisualization tools, this research aims to enhance the understanding and presentation of this park. The methodology is structured into three main stages: (1) data acquisition, using UAVs at different GSD to capture high-precision imagery; (2) data processing, where photogrammetric techniques are applied to generate thematic orthophoto maps and the multiscale 3D model; and (3) geovisualization, which integrates 3D models into an interactive virtual reality (VR) environment. The results demonstrate the effectiveness of multiscale 3D modelling in providing high-fidelity visualizations that preserve both high level of detail 3D models and broader environmental contexts. However, challenges such as model misalignment, texture distortions, and the high computational demands of VR applications were identified. Despite these limitations, the study highlights the significant potential of advanced geoinformation technologies in revolutionizing geoscientific research, geoconservation, and public engagement in geological heritage sites.

ABSTRACT. Two significant subterranean environments in Ecuador have been chosen as proposed candidates for the UNESCO World Heritage List. These are the Tayos cave in the Amazonian basin, and the Triple Volcano Cave in the Galapagos, because both sites represent a unique beauty and meet several criteria of the UNESCO conditions to be considered exceptional Natural Heritage.

ABSTRACT. This study presents detailed geological mapping of the Bali Alonia area within the Lesvos Petrified Forest, a UNESCO Global Geopark in Greece. The research, Through field mapping, aimed to identify locations with standing and fallen petrified trunks and volcanic tuffs such as Lithic and Vitric tuffs, that contributing to the identification and evaluation of fossiliferous horizons associated with distinct volcanic eruptions that preserved fossilized forests. The study area is coverred by the Sigri pyroclastic formation and hosting various fossiliferous horizons. These findings enhance our understanding of the stratigraphic complexity and volcanic history of the Sigri pyroclastic formation. The results highlight the need for further investigation into the geomorphological controls influencing fossil preservation across the region.

ABSTRACT. Geoheritage, rooted in the concept of geodiversity, encompasses Earth’s geological, geomorphological, pedological, and hydrological features significant for conservation due to their cultural, scientific, and educational value. In Greece, the Vikos-Aoos UNESCO Global Geopark showcases exceptional geodiversity, including ophiolites, igneous and metamorphic rocks, and fossil-rich sedimentary formations that narrate Earth’s geological history. The geopark emphasizes the interplay of geoheritage and cultural heritage, fostering education, conservation, and sustainable tourism. To highlight the region’s geoheritage, the Development Agency of Epirus S.A. (EPIRUS S.A.) organized the exhibition “The Rocks of the Vikos-Aoos UNESCO Global Geopark Under the Microscope: Aspects of Their Microcosm,” curated by the School of Geology at Aristotle University of Thessaloniki. Through large-scale petrographic microphotographs, hands-on rock samples, and interactive microscope sessions, the exhibition educated visitors about the geopark’s intricate mineral microcosm. The research conducted for the exhibition advanced knowledge of the geopark’s mineralogy, petrology, and micropaleontology, while exploring new intersections between geoheritage and cultural heritage. Notably, it linked cultural narratives to the large spherical concretions of Gamila peak and the Oxya ophiolites, fostering new research fields and geoeducational opportunities. This publication highlights these findings, emphasizing the significance of preserving and interpreting such unique geodiversity.

ABSTRACT. Introduction The volcanic island of Santorini, aka Th(i)era, is located in the central part of the Hellenic Arc (or Hellenic Subduction Zone), in the South Aegean Sea, where the Nubian (African) and Eurasian tectonic plates converge (Figure 1; Pavlides et al., 2024 and references there in). Santorini has a rich geological history including recent tectonic and volcanic activity, particularly in the last century. The Fira Fault (aka Phera) is one of the most prominent active faults in Santorini (Figure 2). It outcrops on the eastern rim of the Caldera crossing the capital town of the island, in a NE-SW direction. Santorini's fault system includes numerous faults and fractures that contribute to its seismic activity, particularly around the caldera, which has been the focus of volcanic activity for thousands of years. The Fira Fault plays a key role in the ongoing geodynamic processes of the island. In addition to this fault, there are several other active faults around the caldera, including the “Kulumbo (or Columbo) line” and the “Kamenes line” (Pfeiffer, 2001), and others that create a complex tectonic pattern in the region (Figure 2; Mountrakis et al., 1998; see also Nomikou et al., 2021; Sakellariou et al., 2021).

Geodynamic & seismotectonic setting The recent tectonic regime of the Aegean Sea is characterized by a regional extension deriving from the subducting slab’s roll-back and retreat as the Hellenic Arc has been migrating southwards during the last 80 Myr (e.g. Le Pichon & Angelier, 1979; 1981; Jolivet et al., 2013; Barbot & Weiss, 2021; van der Stoel et al., 2024). This extension generates normal faults in the upper crust and rifting in the shallower part of the lithosphere (Jolivet et al., 2013). The extensional thinning of the crust facilitates the magma intrusion from the melting of the subducting slab and the emergence of the Methana, Melos, Santorini, Kolumbo and Nisyros volcanic centres which comprise the volcanic arc. The Santorini–Amorgos offshore basin is a crustal weakness zone in an overall right-lateral oblique-slip transtensional regime, representing a major structural boundary (e.g. Sakellariou & Tsampouraki-Kraounaki, 2019; Tsampouraki-Kraounaki et al., 2021). Santorini Island is an emergent remnant on the central and eastern flanks of a collapsed caldera. Its summit is preserved with over 50 active tectonic structures of the Middle Pleistocene to Holocene. Seafloor topography and subsurface fault data show a complex system of faulting from Christiana island to Amorgos island, with mainly NE trending normal and oblique faults in a right-stepping en echelon arrangement. A tectonic model demonstrating the occurrence of the volcanic centers at the fault segment boundaries is presented. In the case of Santorini – Amorgos Fault System, volcanic centers of Christiana Island, Thera – Kammeni and the submarine crater of Columbo are positioned in the boundaries of the right-stepping en echelon segments of normal and oblique faults. Fault segment boundaries comprise low strength multi-fractured parts of the upper crust, enabling insertion and ascendance of magma dykes. Possible interaction between volcanic activity and fault activation is also investigated based on the early 20th century eruption activity in Kammeni islands and the 1956 double-earthquake event, as well as the 2011-12 volcanotectonic crisis. Dykes and fault swarms are the two main modes of brittle tectonics in the area. The active tectonic structures mainly consist of normal fault systems often in an en-échelon pattern. Reverse and right-lateral, or oblique-slip, faulting also occur in the area. Meso-structural analysis reveals the three main stress axes acting on Santorini and surrounding islets (Tranos & Pavlides, 2012; see also Tranos 2012 ): σ1 in a NE–SW direction, σ3 in a normal direction, and σ2 in the third leading σ2 direction. Santorini’s tectonic structures are then probably the result of this stress field (Manning et al., 2020). Basaltic dykes, associated with neotectonic faulting, are another common feature in Santorini. They are aligned along the axial zone of the submarine caldera and are exposed on the marine cliffs, forming up to a 100-m wide rail on the caldera wall, concentrated on the northern narrow part of the island. The N30°E-trending arc (?) of Santorini and its orientation guide the spatial correlation in the dyke-fault system. This system is expected to be connected at depth because tensional fracturing is expected to occur in fissure eruptions and in the effects of ascending magma within the surrounding rocks (Mountrakis et al., 1998; Ruch et al., 2016). The orientation of the N30°E-striking structures, comprising mostly of normal and a few reverse faults restricted in the alpine basement, represent the local σ3 axis. Northward, in the inner flank of the caldera, tectonic structures document a swelling of the volcanic edifice. The neotectonic map of Santorini in Figure 2 (Mountrakis et al., 1998) indicates the more recent tectonic structures and the active processes shaping the island's landscape. It shows the fault systems, including the Fira Fault and other fractures, which have been active in recent geologic and historical times. This map also highlights the zones of volcanic activity and deformation, which are critical for understanding the island's seismic hazards. The faults that control the eruptive history of Santorini and changes of the magmatic chamber produce characteristic earthquake swarms. The 2011-2012 seismic crisis on Santorini is a typical example.

Morphotectonic study of the Fira fault Neotectonic field studies on Santorini started in 1992-94 and were completed during 2016-22 (Figure 2; see Mountrakis et al., 1998; Pavlides & Chatzipetros, 2018). Among the on land mapped faults, the less studied is the Fira fault, named after the capital town of the Island. The fault has been a prominent feature of Fira cliff (Yalos harbour), and it has been described as a simple tectonic structure since the early French “Expédition de Morée (1829‐38)”. New airborne (UAV) and terrestrial (LiDAR) images were used to produce 2D and 3D photomosaics with photogrammetric methods so as to detect the location and map the Fira fault. Meso-structural analyses, where the fault outcrops in accessible locations, indicate a normal dip-slip sense of movement with a right-lateral strike-slip component on an ENE-WSW (N60°E to70°E) striking fault. According to our 3D terrain model obtained from UAV images, on the very steep inner escarpment of the caldera, fault throw episodically decreases from 22 m at the sea level down to almost 2 m at the highest elevation where the Nomikos Conference Centre is built (Figure 2). At this point, the uppermost lava layer is affected suggesting a syn-depositional normal fault that deforms even the most recent volcanic lava layers and pyroclastic flow strata. This lava layer, which is also the last, 40-60 ka old, volcanic flow, documenting typical cooling fractures and tectonic open joints outcrop, has been vertically displaced. The episodic pattern of displacement can be interpreted as intermittent periods of possibly volcano-tectonic activity rather than simply tectonic. A non-typical fault scarp affecting the volcanics is detected in the urban area of Fira running subparallel to i) a longer “fault zone” which includes the known volcanic centres of Kamenes (Kamenes line), and ii) the large Amorgos-Thera seismic fault which produced the 1956 M7.5 earthquake (Kolumbo line). Due to its proximity to the “Kamenes line”, the Fira fault can be considered as part of this line. The Fira fault is classified as active, as it is documented not only from field observations, but also from the microseismic activity during the 2011‐2012 volcano-tectonic crisis. Its activated length has estimated about 6 km, corresponding to moderate earthquake Ms 5.5 +_ , as calculated from known empirical relationships, while it is possibly extended both towards NE and SW.

Seismic Activity and the Volcanic Crisis of 2011-2012 During the 2011-2012 volcano-seismotectonic crisis, the Fira fault of the “Kamenes line” was activated producing a shallow sequence which slowly initiated in the beginning of late February 2011 and outburst in October of the same year (Kaviris et al., 2015). The strongest earthquake (ML3.3) occurred on January 9, 2012; Five (5) earthquakes with ML ≥ 3.0 preceded and one followed the strongest shock. The local seismicity for the period of interest was accurately located with the use of a local 1D velocity model proposed for the region by Dimitriadis et al. (2009), by applying the NonLinLoc -linear location algorithm (Lomax et al., 2000). The NonLinLoc algorithm utilizes the equal-differential-time (EDT) likelihood function (Zhou, 1994; Font et al., 2004), which uses travel-time differences between observed and synthetic travel times for pairs of stations, resulting to a more robust calculation of the optimal hypocentral location, due to the fact that the 4-D problem (x,y,z, t) is reduced to a 3-D search over space (x,y,z). Furthermore, mispicked phase data can be identified by the methodology and excluded from the solution. The majority of the sequence’s hypocentres is concentrated at very shallow depths (2-6 km). The spatial distribution shows a quite well-formed cluster (cluster A in Figure 3 left) on the SW continuation of the Fira fault which moderately aligned along a NE-SW axis, i.e. parallel to the fault’s strike. Two transverse profiles show the vertical extent of the sequence from ca. 1 km to 12 km depth (Figure 3 right). However, the density differs in the two profiles (Figure 3 right): in the profile B-B’ it is much more concentrated than in profile A-A’. This also explains the moderately linear horizontal trend of the epicentres. In profile B-B’, the density of hypocentres is much higher at depths shallower than 6 km. From this depth and deeper (down to 12 km), a much more linear, SSE steeply dipping trend can be observed, the upward continuation of which also marks the southern limit of the cluster. Thus, two sub-clusters can be distinguished: the shallow one, cluster A1, down to the depth of 6 km, and the deeper one, cluster A2, at depths between 6 and 12 km. Cluster A2 is attributed to purely tectonic causes, and more particularly to the Fira fault. Cluster A1 is probably due to the combined tectonic and volcanic (magmatic) activity if we also take into account the estimation of both volume and depth of the magma intrusion (Newman et al., 2012; Feuillet, 2013; Parks et al., 2012; 2015; Druitt et al., 2016). In more detail, the Fira fault probably restrains the magma chamber to the south and, at the same time, facilitates it movement. The 2011-2012 volcanic crisis in Santorini was marked by increased seismic activity, volcanic unrest, and noticeable ground deformation. This period of volcanic crisis also involved: • Ground deformation: There were reports of ground uplift, which is often associated with magma intrusion or movement beneath the surface (e.g. ISMOSAV, 2013). GPS measurements and InSAR images show both lateral extension and uplift, clearly suggesting inflation (Newman et al., 2012; Foumelis et al., 2013; Papoutsis et al., 2013; Saltogianni et al., 2014). This is typical in volcanic regions where magma rises and causes the earth's crust to stretch or deform. • Magma intrusion: A magma intrusion of 10–25 million m3 is estimated (Newman et al., 2012; Parks et al., 2012; 2015) at a depth of ca. 4 km (Druitt et al., 2016). This magma is suspected to be linked to the dyke systems beneath the island, contributing to the seismic events. A dyke system refers to a network of vertical or steeply inclined fractures filled with magma, often causing crustal deformation and triggering earthquakes.

Conclusions The Fira normal fault shows significant tectonic evidence of recent activity such as fresh scarps and faulted and tilted late Quaternary volcanic strata. It has not been studied in depth. • The Fira fault is a typical normal tectonic structure trending ENE-WSW, with a right-lateral oblique-slip sense of movement. It shows decreasing downthrow from the sea level to the top lava layer, indicating a syn-volcanic deposition fault growth. • It is an active fault in the western part of the Santorini caldera rim, contributing to seismic hazard. • It is a “segment” of sub-parallel, left stepping faults belonging to the larger fault zone of “Kamenes line”, including the known volcanic centers. It is also subparallel to the 1956 earthquake great Amorgos-Thera fault. Its internal structure is complex (under investigation). • The 2011-2012 volcanotectonic crisis was characterized by increased seismicity and ground deformation, linked to magma intrusion and fault activity, associated with the Fira fault. It was a segment of 6 km that was activated by a series of small-magnitude earthquakes, along the Kamenes volcanic line. It is believed to be longer. • This known fault length corresponds to a minor or moderate earthquake. Understanding these elements is crucial for monitoring and assessing the potential volcanic and seismic hazards in the region.

ABSTRACT. In this short paper, we update on the development of the NOAFAULTs geodatabase since 2013. Our objective was to create a nation-scale database of active faults in Greece and its adjacent regions, supporting the seismicity monitoring at the National Observatory of Athens (NOA) in tandem with an associated web-based query system. In the latest version V6.0 we added new data and fault traces, corrected for missing data, reviewed overlapping fault traces, added new thematic layers, and studied the kinematic and geometrical relations from the parametric data. NOAFAULTs can be used to investigate the ground deformation and seismicity patterns in Greece and surrounding areas and to detect new activity along fault zones. The Greek government, research institutions, and companies have widely used the active faults data from the previous versions of the database.

ABSTRACT. Based on the approach and workflow of the recently proposed 3D thermo-rheological model of the broader Aegean Region (Maggini et al., 2023), the present work focuses on the rheological properties corresponding to both the slab interface of the Hellenic Subduction Zone (HSZ) and the basal thrust of the Adriatic-Eurasian continental collision. For the purpose of this note, the geometry of the interfaces (Figure 1) was mainly reconstructed on the basis of the results of Bocchini et al. (2018), especially for the HSZ sector, and Halpaap et al. (2018) for the continental collision zone.

ABSTRACT. Introduction / Background

The study of earthquake impacts on the environment is important for understanding seismic hazards and reducing associated risks. Remote sensing, particularly through Sentinel-1 satellite imagery, offers an effective method for detecting ground displacement and mapping fault systems. The Environmental Seismic Intensity Scale (ESI 2007) provides a robust framework for evaluating earthquake effects on the environment (Michetti et al., 2007) with high precision (Papanikolaou & Melaki, 2017). This study combines Sentinel-1 remote sensing techniques with the ESI 2007 scale to assess seismic hazards and disaster potential by analysing recent seismic events in the Aegean region, focusing on the Kozani-Grevena 1995, Lesvos 2017 and Samos 2020 earthquakes. On 1995 May 13, Kozani and Grevena were struck by an Ms = 6.6 (Mw 6.5) earthquake, causing extensive damage. Meyer et al. (1996) reported surface ruptures over 8 km comprising open fissures and scarps on the pre-existing Palaeochori Fault striking N70◦E. It was preceded by foreshocks, causing significant impacts to buildings, and triggered environmental effects such as rockfalls, landslides, liquefaction, and surface ruptures (Meyer et al., 1998, Hatzfeld et al. 1995, Pavlides et al. 1995, Chatzipetros 1998). On June 12, 2017, a Mw 6.3 earthquake struck southeastern Lesvos Island, causing disasters to the natural environment, buildings, and infrastructure, particularly in southeastern Lesvos. The earthquake's epicentre was offshore, with a depth of ~13 km, and was associated with a NW-SE striking (Papadimitriou et al., 2017), SW-dipping normal fault along the northern margin of the offshore Lesvos basin (Chatzipetros, et. al, 2013). It triggered secondary earthquake environmental effects (EEE) (Lekkas et al., 2017) such as ground cracks, slope movements, and a tsunami in Plomari port, likely caused by offshore landslides (Karamvasis et al., 2017 Vlachakis et al., 2020). The 2020 Samos earthquake, with a magnitude of 7.0, struck the eastern Aegean Sea on October 30th, significantly impacting Samos Island, Greece, and Izmir, Turkey. Caused by normal faulting along the North Aegean Trough, it triggered substantial ground deformation (Mavroulis et al., 2020), including co-seismic uplifts and displacements and produced surface ruptures, landslides, liquefaction, coastal changes, and hydrological anomalies (Foumelis et al., 2021, Ganas et al., 2021, Sakkas, 2021). The Samos earthquake serves as a focal point in such studies.

Methods The methodology integrates advanced remote sensing techniques and field-based analyses to investigate ground displacement and environmental effects caused by seismic events. Sentinel-1 Synthetic Aperture Radar (SAR) data were utilized for pre- and post- seismic periods, with differential interferometric SAR (DInSAR) processing, employed to measure co-seismic deformation. The analysis involved co-registering SAR images, removing the topographic phase using Shuttle Radar Topographic Mission (SRTM) data, unwrapping phase data using SNAP Desktop software. Vertical (up-down) displacement component was calculated from ascending and descending LOS data and was visualized within a GIS environment. Using published and field information about the distribution and magnitude of surface effects and the ESI 2007 scale, the study evaluates environmental impact, such as uplifts, surface ruptures, slope failures, and liquefaction, by mapping and digitizing these data in GIS, producing isoseismal maps with the method of kriging that illustrate intensity patterns. The final step involves an analysis of remote sensing data and traditional field measurements to validate their consistency and potential data overlap.

Results and Conclusions The analysis of ascending Sentinel-1 data (Fig. 1 and Fig. 3) and descending Sentinel-1 SAR data (Fig. 2 and Fig. 4) for the Lesvos and Samos earthquakes demonstrated significant ground displacement, accurately captured through interferometric synthetic aperture radar (InSAR). Moreover, the ascending and descending Sentinel-1 data showed similar results for both seismic events. Field measurements used for the ESI 2007 scale and the seismic intensities ranged from IV to IX, which are broadly in agreement with other studies (Lekkas et al., 2017, Papanikolaou & Melaki, 2017, Mavroulis et al., 2021), reflecting the widespread impacts of all three events. Moreover, the use of the Environmental Seismic Intensity (ESI-07) scale demonstrated its effectiveness in evaluating primary and secondary earthquake environmental effects (EEEs), such as slope failures, liquefaction, and ground cracks, particularly in inaccessible areas. The maps (Fig. 1, 2, 3, 4) of surface co-seismic deformation fields obtained by analysis of interferometric synthetic aperture radar (InSAR) images have significantly improved the description of earthquake effects. The seismic intensity was visualized in isoseismal maps to illustrate the spatial distribution of impacts for the Kozani-Grevena (for which no InSAR data was available Fig. 5), Lesvos (Fig. 6) and Samos (Fig. 7) earthquakes present the spatial distribution of seismic intensity and highlighted areas of heightened risk, enhancing seismic hazard assessment and disaster preparedness for future applications. This integrated approach offered valuable insights into the environmental impacts of seismic events and improved hazard assessment. It also emphasized the complementary roles of remote sensing in covering inaccessible areas and field data for high-resolution, localized studies. The multidisciplinary response shown in these studies demonstrates the growing integration of advanced geospatial technologies, field observations, and historical data in seismic risk assessment. In conclusion, this study underscores the effectiveness of combining Sentinel-1 SAR imagery with the ESI 2007 scale to assess environmental impacts of strong earthquakes. It enhances our understanding of seismic risks by detecting concealed faults and quantifying ground displacement, especially in remote or inaccessible areas. The findings contribute to the ESI 2007 database and highlight the critical role of remote sensing in earthquake research. This integrated framework has the potential to strengthen disaster preparedness and response strategies, providing a foundation for future advancements in seismic risk assessment.

ABSTRACT. The Emilia Romagna region, hosts part of the outermost sector of the northern Apennines. This domain is affected by a contractional stress dynamic results from the westward subduction of the Adriatic lithosphere and its flexural retreat. This process leads the formation of a thrusts and fold belt system, migrating toward east and north-east (Malinverno and Ryan, 1986; Fig. 1 a - b). The above-mentioned regional dynamics, determine a shortening deformation pattern, in the interseismic period, probably accommodated by various faults hidden below the Po-Plain, which represents the nowadays foredeep of the northern Apennines. In this work, we apply a kinematic Block Modeling approach (McCaffrey, 2002), to investigate which faults, striking across the Po Plain, is actively accommodating the recognized geodetic velocity field. We use several GNSS data available in these areas (Serpelloni et al., 2022), and exploit all the available fault parameters (e.g., position, strike, dip angle and locking depth) from previous studies and database, to verify the role of major fault segments in accommodating the given velocity field. Our solution shows that the outermost sector of the Northern Apennines, which includes the Mirandola fault and Ferrara Thrusts System, is characterized by contractional slip rates, at most equal to 1.5 mm/yr (dip-slip component), that reproduce the observed velocity field in the long-term (Fig. 2 a). These two above mentioned faults have been widely studied during the last years because of their capability of generating high magnitude earthquakes. An example is the 2012 seismic sequence, characterized by two mainshocks occurred on 20 May (Mw ~ 6) and 29 May (Mw ~ 5.8), (Lavecchia et al., 2012; Fig. 1 b). Due to the complex seismotectonic history of the studied domain, we discretise the northern Apennines external Arc by means of a Triangular Dislocation Elements (TDEs) mesh to resolve the variability of the slip-deficit rate pattern on fault planes. (Fig. 2 a) According to Meade and Loveless (2009), we calculate the interseismic coupling degree as the ratio of the slip deficit and the long term slip derived from the relative motion of the bounding blocks (Fig 2 b). We therefore investigate each fraction of coupling increment to discern portions of fault planes characterized by a complex behaviour (e.g., aseismic creep vs elastic responses). Finaly, we detect at least three locked asperities, with which we propose a set of possible rupture scenarios and calculate the amount of seismic moment rate that the Emilia Romagna region is accumulating. The obtained seismic moment accumulation rate (3.21 e16 Nm/yr) is higher than the rate of the released seismic moment (2.2 e16 Nm/yr) in the last ~35 years. Assuming that all this energy (1.01 e16 Nm/yr) is released elastically, it would be the equivalent of an earthquake of Mw ~ 4.4, each year.

ABSTRACT. The broader Aegean Region including the Southern Balkans is among the most tectonically active areas of the Mediterranean realm and has the highest seismicity both in terms of frequency of events and magnitudes. The principal aim of this note is to present the new release of the Greek Database of Seismogenic Sources (GreDaSS) corresponding to version 3.0 (Figure 1).

ABSTRACT. The purpose of the present study is to investigate the exposure of beach sectors from 4 different coastal areas of the Greek mainland The Kotychi lagoon, the Alfios River deltaic coast (north Kyparissiakos), the beach/dunes in the central Kyparissiakos coast and central part of the north coast of the Messiniakos Gulf, and four beaches from the coast of Attiki

ABSTRACT. This paper introduces a semi-quantitative multi-hazard approach for assessing the stability of Tailings Storage Facilities (TSFs). It adapts Liu's method (Liu et al., 2021), evaluating individual hazards (earthquake, rainfall, flooding, landslide) and their interactions with TSF failure modes (overtopping, slope instability, liquefaction, etc.). A case study in Northern Greece demonstrates the methodology, assigning intensity values to hazards and calculating a multi-hazard intensity (MH) for each scenario. Overtopping emerges as the most critical failure mode. The study highlights the importance of considering multi-hazard interactions for accurate risk assessment of TSFs.

ABSTRACT. The Troodos Mountain region and especially the area of Troodos UNESCO Global Geopark is increasingly affected by climate change, leading to both direct environmental impacts and indirect socio-political challenges. Within the framework of the ClimEmpower project, this study applies an integrated methodological approach to assess climate change effects on the region. Using climatic modeling, remote sensing, and stakeholder engagement, we analyze temperature and precipitation shifts, ecological responses, and their implications for local communities. A key aspect of this research involves Community of Practice (CoP) meetings, which serve as collaborative platforms for gathering local knowledge, discussing potential solutions, and identifying key indicators for risk assessment. These indicators will be used to develop climate risk maps, offering valuable tools for adaptive planning and mitigation efforts. The CoP meetings also provide insight into the socio-economic struggles of Troodos residents, who face intensifying natural hazards such as droughts, wildfires, and biodiversity loss, alongside governance inefficiencies, resource management conflicts, and gaps in scientific communication. By integrating scientific analysis with community-driven data, this study highlights the need for inclusive, adaptive governance strategies. Bridging the gap between research findings and local needs is essential for enhancing resilience in mountain communities. The findings contribute to the broader discourse on sustainable adaptation strategies, ensuring that policy interventions are both evidence-based and community-responsive.

ABSTRACT. Introduction Coastal floods from extreme marine events have had increasing impacts on the coastal natural and human ecosystems, causing coastline changes, biodiversity losses, human mortality, increased health risks and poverty and induced coastal infrastructure/asset damages (IPCC, 2023). Under climate change, the frequency of extreme events is projected to increase and expose annually a large part of the global coastline to the current 1 in 100 years Extreme Sea Level by 2100 (Vousdoukas et al., 2018). ‘Sandy’ shorelines (i.e., the low-lying coasts built on sediments—beaches), which comprise a large segment of the global coastline (Luijendijk et al., 2021) will be particularly vulnerable. In addition to their own importance as ecosystems, beaches form natural buffers that protect backshore ecosystems, infrastructure, and assets from coastal flooding (Toimil et al., 2023); they also have high hedonic/recreational value, contributing very significantly to the tourism sector due to the current dominance of the ‘Sun, Sea, and Sand—3S’ model (UNWTO, 2024). Beaches in touristic islands face increased vulnerability to coastal flooding, due to their generally limited width, scarce sediment supply and the high potential exposure to coastal flooding of their backshore infrastructure and services (Brett, 2021). However, the flood assessment of beaches, presents certain challenges due to the need for accurate geospatial information, as well as the accuracy/costs of the used models (Almar et al., 2021).

Figure 1. (a) Chios island and Komi beach, showing Katraris river and dam (blue line and circle). (b) Beach nearshore topography/bathymetry. Photos of Komi beach, (c) from the ENE under calm conditions and (d) from WSW during a storm.

Therefore, the objective of this short contribution has been to assess the flood risk of an island beach (Komi, Chios; Fig. 1), using readily available geo-spatial information and an open - source numerical model. Komi is a 1.2 km long barrier beach with a maximum dry width of 38 m. Its backshore hosts a coastal road and many residential and touristic assets, sometimes at a distance of <10 m from the coastline. The beach is characterized by low slopes with elevations that in many areas do not exceed 1.5 m (slopes of approximately 3%). In addition, the backshore elevations are in many areas <1 m. A stream is present at the western segment of the beach, whereas at its eastern end there is a small fishing port. The stream is the outlet of the Katraris river, the land sediment supply of which has been diminished due to the construction of the Kalamoti-Katraris Dam (Andreadis et al., 2021). Methods In addition to the simple static inundation ‘bathtub’ model, a simplified two-dimensional finite difference hydrodynamic model LISFLOOD-FP (Bates and de Roo, 2000) was also used. This simulates flood dynamics in a pre-designed grid using a Digital Elevation Model (DEM). Specifically, LISFLOOD-FP applies fluid continuity to calculate the depth at each grid cell while the water flow is channeled along the ground using a simple storage algorithm based on the difference in hydraulic head between adjacent cells (Bates et al, 2005). In each cell, the calculated height of the water surface above the topographic elevation as well as the Manning soil friction coefficient are used to calculate the flow rate. The water flow is described by the momentum conservation and mass continuity equations: [1] [2]

where, (Qt) is the flow at time (t) between cells, calculated using a centered difference scheme resolved in the (x) or (y) direction; (hij) is the water depth at the center of cell (i, j); (hflow) is the depth between cells where flow is possible; (z) is the topographic height in the cell; (n) is the ground friction coefficient; (g) is the acceleration of gravity; (q) is the flow from the previous time step; and (Δt, Δx) is the width of the cell. The flood flows are discretized into a grid of square cells, thus allowing the model to represent two-dimensional flows on the ground surface. LISFLOOD-FP results (ascii files) can be easily imported into a GIS environment for further analysis. The model had been originally designed to simulate river floods, but, in recent years, has been also successfully used to simulate coastal floods (e.g., Monioudi et al., 2018; Le Gal et al., 2023). The DEM of Komi beach used the 'Digital Terrain Model of the LSO25 project' (LSO - Large Scale Orthophotos) of the Hellenic Cadastre, which was constructed using high-resolution aerial photographs (2014-2016). The Cadastre DEM has a resolution of 2 m, which allows capture of both the slopes of the coastal topography and adjacent coastal works with much greater accuracy than the EU-DEM (resolution of 25 m, spacedata.copernicus.eu/documents/20123/121239/GEO1988-CopernicusDEM-RP-001Validation Report_I3.0.pdf). Application of the model at a local level allows the use of this specific spatial resolution with a very reasonable computational cost. The DEM were processed in QGIS software. The Manning friction coefficient was calculated on the basis of the land uses recorded in the Coastal Zone Land Use/Land Cover (LU/LC) geospatial file of the European Copernicus service (https://land.copernicus.eu/en/products/coastal-zones). Manual corrections were applied, which mainly concerned the more accurate design of the beach boundaries (and coastal works and port facilities). As an additional check, the corrections were also taken into account in the DEM of the area to ensure that there were no significant discrepancies between the land uses and the topography, e.g. the polygon corresponding to the sea was checked to overlap pixels with zero elevation. Then, a value for the Manning coefficient was entered for each land use, using the calculations of Papaioannou et al. (2018). The model was driven by the projected Extreme Sea Levels (ESLs) for Chios under the RCP8.5 climatic scenario for 2050 and 2100 extracted from the EU-JRC (Joint Research Centre) database https://webcritech.jrc.ec.europa.eu/SeaLevelsDb detailed in Vousdoukas et al. (2018). ESLs were projected using the numerical hydrodynamic model Delft3D-Flow driven by the wind and atmospheric pressure fields corresponding to the climate conditions of the RCP4.5 and RCP8.5 scenarios calculated by an ensemble of 8 climate models; model performance was assessed for the period 1980 – 2014 (baseline) driven by wind/atmospheric pressure fields extracted from the ERA – Interim database. The ESLs form the sum of the future long-term relative mean sea level rise (RSLR), the astronomical tide (nt) and the episodic sea level rise (nce) due to meteorological tides (storm surge) and the storm wave set-up; the latter, which can be quite significant during an energetic event, is set using a generic approximation of 0.2 Hs, i.e., of the offshore significant wave height projected for the same scenarios. Results The ESLSs with return period of 100 years (ESL100) projected for the area were 1.12 m and 1.77 m for 2050 and 2100, respectively. The bathtub model results showed inundation of 70,850 and 128,300 m2 for 2050 and 2100, respectively, with maximum flood extent more than 220 m and 260 m. The projections show that a large part of the area will be flooded (Fig. 2), with maximum flood extents of 118 m and 190 m for 2050 and 2100 respectively, The beach itself is projected to be completely inundated, presenting a flood risk to all assets at its immediate backshore. Already from 2050 the flood appears to significantly penetrate inshore at the western beach, affecting assets along and to the west of the stream. By 2100, the flood is projected to reach >100 m to the east and west of the stream affecting considerable infrastructure/assets, while the small fishing port will be completely flooded. Overall, it is clear that due to the low relief and many backshore infrastructures/assets there is a high food risk that can cause serious damages/losses, especially if combined floods (i.e., from land and the sea) are considered, which is a likely occurrence during extreme storms.

Figure 2. Flood extent at Komi beach in 2050 and 2010 under theRCP8.5 scenario. The different colors correspond to the estimated beach width that will be flooded.

Discussion and Conclusions The results show considerable inundation for Komi beach which is projected to be worse by the ‘bathtub’ approach. However, the static method is considered to overpredict the flood extent, mainly because it ignores bed friction effects on the flood flow as well as its flood inundation predictions for cells are not hydraulically connected with the rest of the flooded area. Similar discrepancies between the two approaches have been found also in other island beaches (Chatzistratis et al., 2024). In general, flood simulations with numerical models appear more appropriate for local scales while on regional assessment the bathtub approach may be used as fine grids for numerical modelling increase substantially the computation cost (Seenath et al., 2016). Moreover, LISFLOOD-FP provides outputs of flood characteristics at user defined timesteps, providing significant information for flood risk preparedness. It should be noted that the coastal flood risk in Komi is likely to be exacerbated by the beach erosion/retreat due to the relative sea level rise (RSLR). Andreadis et al. (2021) have estimated that Komi beach retreat due to the RSLR will be 3-9 m and 6-9 m by 2050 and 2100, respectively, even under the moderate RCP4.5 climatic scenario. It is noted that these beach erosion/retreat projections are even more conservative, as they do not take into account the (cumulative) effects of storm events (which, both observations and modeling suggest, could be significant at Komi beach), or the effects of the diminished land-sourced sediment supply due to the construction of the Kalamoti-Katraris Dam. Therefore, in order to assess the flood risk more accurately, coupled beach erosion/flood models will be required. Although such models present large challenges, particularly due to uncertainties at the land/sea boundary condition, future efforts should be focused on it as a response to the major flood disaster risks under climate change. Acknowledgements This work was supported by the Project ‘Coastal Environment Observatory and Risk Management in island Regions AEGIS+’ (MIS 5047038), implemented within the Operational Programme ‘Competitiveness, Entrepreneurship and Innovation’ (NSRF 2014-2020), co-financed by the Hellenic Government (Ministry of Development and Investments) and the European Union (European Regional Development Fund).

References Almar, R., Ranasinghe, R., Bergsma, E.W.J. et al., 2021. A global analysis of extreme coastal water levels with implications for potential coastal overtopping. Nat. Commun. 12, 3775. https://doi.org/10.1038/s41467-021-24008-9 Andreadis, O., Chatzipavlis, A., Hasiotis, T., Monioudi, I., et al., 2021. Assessment of and Adaptation to Beach Erosion in Islands: An Integrated Approach.. J. Mar. Sci. Eng. 9(8), 859. https://doi.org/10.3390/jmse9080859 Bates, Paul D., De Roo, A.P.J., 2000. A simple raster-based model for flood inundation simulation. J. Hydrology 236, 54-77 https://doi.org/10.1016/S0022-1694(00)00278-X Bates, P., Dawson, R., Hall, J., et al., 2005. Simplified two-dimensional numerical modelling of coastal flooding and example applications. Coast. Eng. 52 (9), 793-810. https://doi.org/10.1016/j.coastaleng.2005.06.001 Brett, R., 2021. How Important Is Coastal Tourism for Island Nations? An Assessment of African and Indian Ocean Islands. J. Coast. Res. 37, 568–575. https://doi.org/10.2112/JCOASTRES-D-20-00011.1 Chatzistratis, D., Monioudi, I., Velegrakis, A.F., Chalazas, Th., Tragou, E., 2024. Exposure to coastal erosion and flooding in the Northeastern Aegean islands, Greece, in Briand F. (Ed.), CIESM Monograph 52, Marine hazards, coastal vulnerability, risk (mis)perceptions – a Mediterranean perspective, CIESM Publisher, Paris, Monaco, 115- 130. IPCC, 2023. Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, Core Writing Team, Lee, H., Romero, J. (Eds.), IPCC: Geneva, Switzerland. Le Gal, M., Fernández-Montblanc, T., Duo, E., Montes Perez, J., Cabrita, P., Souto Ceccon, P., Gastal, V., Ciavola, P., Armaroli, C., 2023. A new European coastal flood database for low–medium intensity events. Natural Hazards and Earth System Sciences 23, 3585–3602. https://doi.org/10.5194/nhess-23-3585-2023 Luijendijk, A., Hagenaars, G., Ranasinghe, R. et al., 2018. The State of the World’s Beaches. Sci. Rep. 8, 6641. https://doi.org/10.1038/s41598-018-24630-6 Monioudi, I.Ν., Asariotis, R., Becker, A., et al., 2018. Climate change impacts on critical international transportation assets of Caribbean Small Island Developing States (SIDS): the case of Jamaica and Saint Lucia. Regional Environmental Change 18, 2211-2225. https://doi.org/10.1007/s10113-018-1360-4 Papaioannou, G., Efstratiadis A., Vasiliades, L., Loukas, A., Papalexiou, S.M., Koukouvinos, A., Tsoukalas, I., Kossieris, P., 2018. An operational method for flood directive implementation in ungauged urban areas. Hydrology 5, 24. https://doi.org/10.3390/hydrology5020024 Seenath, A., Wilson, M., Miller, K., 2016. Hydrodyanmic versus GIS modelling for coastal flood vulnerability assessment: Which is better for guiding coastal management? Ocean & Coastal Management 120, 99-109. https://doi.org/10.1016/j.ocecoaman.2015.11.019 Toimil, A., Losada, I.J., Álvarez-Cuesta, M., Le Cozannet, G., 2023. Demonstrating the Value of Beaches for Adaptation to Future Coastal Flood Risk. Nat. Commun. 14, 3474. https://doi.org/10.1038/s41467-023-39168-z UNWTO, 2024. International Tourism Highlights. World Tourism Organization: Madrid, Spain, ISBN 978-92-844-2579-2. Vousdoukas, M.I., Mentaschi, L., Voukouvalas, E., et al., 2018. Global probabilistic projections of extreme sea levels show intensification of coastal flood hazard. Nat Commun 9, 2360. https://doi.org/10.1038/s41467-018-04692-w

ABSTRACT. Fine particulate matter (PM2.5) poses significant health risks due to its ability to penetrate deep into the respiratory system and induce oxidative stress, leading to various cardiovascular and respiratory diseases. This study conducts a comprehensive long-term analysis of PM₂.₅ composition and its oxidative potential in Los Angeles from 2001 to 2024, utilizing data from the University of Southern California’s Particle Instrumentation Unit and the Environmental Protection Agency’s Air Quality System (AQS). The oxidative potential of PM2.5 was assessed using the dithiothreitol (DTT) assay, which measures the capacity of particles to generate reactive oxygen species (ROS), serving as an indicator of their toxicity. Our findings reveal that stringent regulatory interventions implemented between 2001 and 2016 effectively reduced PM₂.₅ mass concentrations and primary combustion-related components, such as organic carbon (OC) and elemental carbon (EC). During this period, PM2.5 oxidative potential, as measured by the DTT assay, declined sharply from approximately 0.84 to 0.16 nmol/min/m³. However, post-2016, despite continued reductions in PM₂.₅ mass, the oxidative potential stabilized and began to increase, reaching nearly 0.97 nmol/min/m³ by 2024. This resurgence is attributed to the rising influence of non-tailpipe emissions, including brake and tire wear, as well as the formation of secondary organic aerosols. Metals such as iron (Fe) and zinc (Zn) maintained relatively stable concentrations while OC and EC continued to decline, indicating that non-tailpipe sources have become dominant contributors to PM2.5 toxicity. The study highlights the limitations of mass-based air quality standards, which may not fully capture the toxicological shifts in PM2.5 composition. The increasing oxidative potential despite lower PM2.5 mass underscores the need for regulatory frameworks to address emerging non-tailpipe emission sources and secondary aerosol formation. To enhance public health outcomes, policymakers should integrate toxicity metrics like oxidative potential into existing standards and implement targeted strategies to mitigate emissions from non-traditional sources. This comprehensive analysis provides critical insights into the evolving nature of PM2.5 toxicity in urban environments and underscores the necessity for adaptive regulatory measures to effectively manage air quality and protect public health.

ABSTRACT. The area of Crete is one of the most tectonically active in Greece and its study has been at the centre of interest of many researchers. Eastern Crete is considered to be the area where 80% of the future normal fault earthquakes will occur (Nicol et al., 2020), so seismic hazard assessment is a necessity. The Ierapetra fault zone is considered the most dangerous and important, as two major earthquakes have occurred in the past, destroying completely the city of Ierapetra. Therefore, the mapping and analysis of the area's major fault zones can provide substantial insight into the seismic hazard of the region. The study area is located in the eastern part of Lasithi and includes the municipality of Sitia and part of the municipality of Ierapetra. It is characterised by a relatively mountainous landscape with numerous gorges formed in the limestone bedrock. The geological structure of the area, from the lowest to the highest units, consists of the following units: Plattenkalk unit, Tripali unit, Phyllite-Quartzite unit s. str., the pre-alpine basement, the Tyros Unit, the Tripoli Unit, the Pindos Unit and then, above all, the younger post-alpine sedimentary series (Fassoulas, 1995, ten Veen and Postma, 1999, Seidel, 1968; Krahl et al., 1983; Zulauf et al., 2008, Klein et al., 2008, Mountrakis, 2010, Krahl et al., 1986; Zulauf et al., 2013, Robertson, 2006; Robertson, 2008; Robertson, 2022). Active faults in the area are normal or normal-oblique ones. They are numerous and can be grouped into two main trends: the NNE-SSW trending fault group and the E-W to ESE-WNW trending fault group. The Ierapetra Fault Zone, as mentioned above, has been mapped and analysed in detail. Other fault zones mentioned in previous research include the Sitia Fault Zone and other minor offshore and onshore structures, such as the Goudouras Fault, the Mouliana Fault and the Orno Fault (ten Veen and Postma, 1999, Caputo et al., 2010, Caputo and Pavlides, 2013, Mason et al., 2016, Pavlides et al., 2018, Veliz et al., 2018, Mechernich et al., 2023). On 12 October 2021, an M 6.3 earthquake occurred on an offshore NNE-SSW fault, its focal mechanism (data from the National Observatory of Greece, Dretaki et al., 2022), showed that the active stress field is compatible with several onshore fault zones and indicating the need for further research into the tectonic activity of the area. To estimate the seismic hazard, empirical relationships are used that relate the surface rupture (L) to the energy released by the earthquake (magnitude Ms) (Pavlides, 2016). Many researchers have already calculated the possible magnitudes of some faults in the area and the results are shown in Table 1. During the field mapping, measurements of faults and structures were taken where possible. Then, using ArcGIS Pro software, they were analysed and correlated with the satellite imagery and DEM in order to better map them in the field. From the above analysis, the structures were divided into five fault zones, Xerocampos - Goudouras, Sitia, Orno, Mesa Mouliana and Ierapetra (Figure 1). Each was divided into individual fault subzones based on their segmentation and correlated with the satellite data, Digital Elevation Model (Data Source: Legal Entity of Public Law Hellenic Cadastre, Operational Programme Competitiveness, Entrepreneurship and Innovation 2014-2020 (EPAnEK)) and digitized geological map (IGME 1959). The hydrographic network was also used, since the way it develops can be strongly influenced by the tectonic regime of a region. All of the above, combined with the analysis of morphotectonic indices and data published in the literature, led to the assessment of the activity of each zone. Then, the seismic hazard was calculated, using empirical relationships, for each segment of sufficient length, combinations of segments, the entire fault zone, combinations of fault zones and the entire deformation zone. For the calculation of the Ms magnitude of the faults the empirical relationships of Wells & Coppersmith (1994), Papazachos et al. (2004) and Pavlides & Caputo (2004) were used First, the surface length L or SRL (Surface Rupture Length) of each section was calculated separately in km using the ArcGIS Pro application for the mapped sections. Then the values of the potential magnitudes and the Maximum Vertical Displacement (MVD) were calculated. The values were calculated for each individual segment, combinations of segments and the whole zone and the results are shown in Tables 1, 2 and 3. Previous work in the area (Dretaki, 2024) confirmed that both groups are active, with the NNE-SSW faults being more active than the E-W ones. The above analysis, in addition with previous studies, shows that the Ierapetra, Mesa Mouliana, Sitia and Xerocampos - Goudoura Fault Zones are the most active in the region. In the Ierapetra Fault Zone there are historical records of its activation. Segment 52 (Figure 1), which was recently mapped during fieldwork (Dretaki, 2024), shows evidence of activity as it deforms recent deposits and has the potential for a magnitude Ms 5.7 event (Pavlides and Caputo, 2004). Further investigation of this fault segment is considered important. The Mesa Mouliana Fault Zone is considered to be as active as the Ierapetra one, with potential similar to that of Lastros fault (Mechernich et al. 2023), with calculated Ms 5.7 (Pavlides and Caputo, 2004). It intersects the Orno Fault Zone, which is also considered to be active, creating strong relief and slope debris have been deposited in the hanging wall. Orno fault has a potential magnitude of Ms 6.8 (Pavlides and Caputo, 2004). Sitia Fault Zone is an active zone with signs of activity migration towards the centre of the basin. The younger parts of it intersect the Neogene deposits, but more importantly they intersect the beachrocks of Sitia beach, indicating that it was active during the Holocene. The activation of the entire fault zone could cause an earthquake of Ms 7.1 (Pavlides and Caputo, 2004), similar to Ierapetra and Xerocambos-Goudouras Fault Zones. Xerocampos Fault Zone, as well as the large expected earthquake magnitude derived from empirical relationships, appears to be part of the same system as the 12 October 2021 earthquake. Based on the above, as well as the results from Tables 1 to 3, we can conclude that further research on each area is mandatory. This research could include the monitoring of micro-movements by installing instruments in the most active sections, geophysical surveys and paleoseismological trenching. Although the study area is the least developed in terms of tourism compared to the rest of Crete, it receives many visitors each year. Combined with the permanent population, especially in the settlements close to the fault zones, the seismic risk of the area is greatly increased due to the age of most of the settlements, the short distance from the seismic sources and the permanent human presence.

ABSTRACT. Introduction Milos is located at the southwestern edge of the Cyclades islands in the Aegean Sea, Greece, and is part of the South Aegean Volcanic Arc (Pe-Piper, et al., 2005). The island's geological history includes volcanic activity from the Late Pliocene to the Early Pleistocene, with the last subaerial eruption occurring around 80,000 years ago (Sonder, 1924; Fytikas, 1977; Fytikas, et al., 1986). Its tectonic background is characterized by alternating phases of extension and compression related to volcanic activity during the Pliocene-Pleistocene (Angelier, et al., 1977). The neotectonic and active faults of Milos have produced a block structure, characterized by the occurrence of specific stratigraphic formations in each block (Papanikolaou, et al., 1990). These faults have served as conduits for geothermal fluids, resulting in hydrothermal alteration of the adjacent volcano-sedimentary formations and giving birth to several exploitable ore deposits (Fytikas, 1989). The most active onshore vent fields are located in the Aghia Kiriaki area, along the eastern edge of the Fyriplaka Volcano, near the intersection of the NW-SE and ENE-WSW active faults. As for the offshore domain, extensive hydrothermal venting has been documented in Paleochori, Adamas Bay and Voudia Bay (Dando, et al., 1995; Dando, et al., 2000). Specifically, in Paleochori area, from shore up to depths of almost 500 m, hydrothermal venting is manifested through emissions of gases and high-temperature fluids, often associated with bacterial mats and/or hydrothermal mineral precipitates (Puzenat, et al., 2021). Highly dominant tectonic features are two major fault zones bounding the central block of the Milos – Fyriplaka tectonic graben, which hosts the Fyriplaka volcanic crater and numerous vent fields both onshore and offshore (Papanikolaou, et al., 1990). Seismic activity, such as the earthquake of 5.2 ML on March 20, 1992, in the southeastern part of the graben, caused extended impacts, including structural damage on buildings, seismic fractures, variations in intensity and temperature of gas emissions, landslides, rockfalls and liquefaction phenomena (Papanikolaou et al., 1993). Α recent study has confirmed ongoing seismic and ground deformation along a NW-SE, east-dipping fault on Milos Island, through microseismicity recordings, and InSAR data, showing a significant ground motion of up to 1 cm/yr across the fault (Ganas et al., 2022). This study combines geodynamic constraints with high-resolution geophysical data to determine the influence of tectonic processes over the distribution of hydrothermal vent fields on the continental shelf around Milos as well as their evolution in relation to sea-level changes particularly since Middle Pleistocene, with the most recent lowstand averaging around 130 m in depth (Seibold & Berger, 1993), thus documenting the interconnection of hydrothermal activity associated with volcanism, tectonics and climatic fluctuations both onshore and offshore.

Data collection and Methodology The cruise M192, conducted in August 2023 on board the RV Meteor investigated the area offshore Milos in terms of the geomorphology, geology, geochemistry and microbiology of marine hydrothermal systems in a transect from the shallow continental shelf, photic zone off Milos to the deep, offshore, aphotic zone (Bühring et al, 2024, Nomikou et al., 2025 under review). The mission was separated into 2 legs. The major aim of Leg 1 was the systematic mapping using the multibeam echosounder system of RV Meteor, the parasound system and the AUV (Autonomous Underwater Vehicle) MARUM-SEAL in expansive areas around Milos was performed during cruise M192 of R/V Meteor, 08 August – 05 September 2023. On the second leg (M192_2) the hydrothermal vent areas targeted during the first leg were systematically sampled by multicorer and identified with the ROV MARUM-SQUID.

Results and Discussion Processing of the acquired bathymetric data revealed that the coastal zone around Milos features a distinct shelf and slope area separated by a shelf break, which varies in depth around the island (130-220m), being deeper and disrupted on the eastern side (Fig. 1). The shelf break depth varies due to tectonic deformation, from 130-150 m on the western block (consistent with pre-Holocene sea levels) to 170-220 m in the southeastern tectonic graben, reflecting active faulting. This survey also provided us with the first documentation of Hydrothermal Vent Fields (HVFs), related to volcanism in the modern Milos geothermal system, up to depths of about 220 m and confined within the continental shelf. The distribution of the discovered vent fields around Milos Island is highly selective at the SE and NW coastal zone covering a small percentage of the Milos offshore domain. The present study reveals that these vent fields illustrate a strong correlation between hydrothermal vent fields and active faults, highlighting the interplay between tectonics and geothermal activity. Some of the discovered vent fields are associated with the NW-SE Milos Gulf–Fyriplaka tectonic graben, which hosted the last volcanic eruption 80,000 years ago. Others align with E-W and WNW-ESE faults in southeastern Milos. Two key tectonic features, the NW-SE Milos Gulf–Fyriplaka graben and the ENE-WSW fault system near Fyriplaka Volcano, separate the island’s geothermal activity. The most active offshore vent fields occur at Paleochori (Puzenat, et al., 2021) along the southern coast, while Aghia Kiriaki (Fig. 1) hosts the primary onshore vent field at the intersection of active faults. Depths of detected hydrothermal activity reveal distinct distributions varying in depth from 130 to 220 m. Despite this variation, the prevailing depth is around 110 m, with fewer hydrothermal manifestations beyond 150 m. The shelf break subsidence due to tectonic processes thus seem to strongly influence the location, depth, and activity of geothermal vent fields, with faults acting as conduits for hydrothermal fluids while leaving other regions inactive. Notably, the E-W neotectonic faults of SW Milos and NE-SW trending faults on the SE slope do not extend onto the shelf and lack associated hydrothermal activity creating geothermal activity gaps. Conclusions The oceanographic research M192 around Milos, a young volcanic island in the South Aegean, revealed the offshore prolongation of the Milos major tectonic zones and their interconnection to high-temperature hydrothermal vents and continental shelf volcanism. Hydrothermal activity has persisted beneath the Milos shelf since the Late Pleistocene, independent of active faulting, and continues today. This evolution reflects a combination of tectonic processes and climatic shifts, alternating between subaerial erosion during sea-level lowstands and submarine venting during highstands. These findings may apply to similar volcanic and geothermal systems in island arcs at convergent plate boundaries.

ABSTRACT. Active tectonics of the Aegean is mainly influenced by the interactions of the North Anatolian Fault (NAF) branches, that extend into the Aegean Sea, the counter clockwise rotation and westward extrusion of the Anatolian block, the Hellenic Trench retreat, and the left-lateral strike-slip Pliny-Strabo Shear Zone (PSSZ), that extends towards the Isparta Angle (IA), (Dewey & Şengör, 1979; Taymaz et.al., 1991; Yılmaz & Gürer, 2013).

ABSTRACT. The "wider area of Paligremnos and Cape Psarela" of the Municipality of Agios Vasilios of Rethymno has special and remarkable characteristics of the geological and geomorphological environment, hosts endemic forms of flora and fauna of Crete and gathers rare and unique for Crete cultural elements related to mining and quarrying activities of the past. In 2022 the initiation of excavations for touristic apartments motivated local community and foreigners to protest and request the protection of the area. The Municipality assigned a Special Study to the Natural History Museum of the Univ. of Crete to document the value of the area and the need for protection and conservation. The study revealed that the “wider area of Paligremnos and Cape Psarela" constitutes a geosite unique in Greece and diverse in its geological and geomorphological characteristics. It includes a zone of three faults with the largest naturally exposed and most impressive, monumental, fault scarp surface of our country, five successive marine terraces and other indications of the recent tectonic uplift of Crete, as well as caves and sand dunes in the coastal zone. All these constitute a fragile, tectonically active and dynamically changing by natural processes, environment which contributes to the existence and preservation of rare and endemic species of flora and fauna of Crete, and which has great scientific, aesthetic and educational value. All of the above elements make up a rare and attractive destination and one of the main reasons for the tourist development of the area to date, which finally led in 2023 in its recognition as a Protected Landscape under the Greek legislation.

ABSTRACT. The Aegean Sea and its surrounding region is one of the most tectonically and seismically active areas in the world, as it lies within the convergence zone between the African and the Eurasian plates along the Hellenic Arc and Trench system; it is a highly segmented tectonically active domain, characterised by high-rate crustal extension and severe thinning. The different segments (blocks) comprising the South Aegean crust are bounded by significant fault zones and/or dislocation surfaces whose relative motion varies in size and direction. Herein we attempt to investigate the sizes, distribution, and kinematic characteristics of these segments, and develop a contemporary tectonic model of the area, using 54 permanent, continuously recording GNNS stations spanning a mean period of 7 years and distributed over the eastern Peloponnesus, Attica, Cyclades, Dodecanese, Crete and the coast of western Anatolia. The regional velocity field of ground deformation was first obtained in the ITRF 2008 global reference frame; based on this information, the regional strain field was also derived. Moreover, to resolve the relative motions between blocks, the local-scale residual velocity fields of ground deformation were derived using three local reference points located at Attica (Anavyssos), the Cyclades (Naxos Island) and the Dodecanese (Astypalaea Island). Finally, to further constrain the relative motion between blocks, seismotectonic information was included, in the form of all available focal mechanisms of earthquakes with Mw ≥ 4 in the period 1904–2022. The joint analysis of all these data points toward an intricate tectonic deformation pattern comprising 7 major crustal blocks that accommodate rapid south-eastward divergence of the eastern Cyclades and the Dodecanese and moderate south-eastward divergence of the western Cyclades and the Myrtoan and Cretan seas. The details of the resulting tectonic model are duly presented and discussed.

ABSTRACT. The Aegean region is a tectonically active microplate situated between the converging Eurasian and African plates, shaped by complex deformation patterns resulting from the movement of the Anatolian Block through the North Anatolian Fault (NAF). This study focuses on the southern part of Lesvos Island, particularly the area extending from the eastern edge of the Gulf of Kalloni to the Vatera vicinity, in order to investigate the fault network and its influence on seismicity in the region. Through geological mapping, structural analysis, and inerpretation of recent onshore and offshore data, the relationship between the fault patterns, the formed basins, and their tectonic significance is examined. The fault zones in the study area, primarily characterized by strike-slip and normal sense of shear, reflect a transtensional tectonic regime. The Vrisa Fault Zone (VFZ), the Vatera Fault Zone (VtFZ), the Aghios Fokas Fault Zone (AFFZ) and the Lesvos Fault (LF) are identified as key structures controlling basin formation, such as the Vatera and the Lesvos Basin, which are developed due to local extension between these fault zones. Furthermore, the Lesvos Fault and associated structures demonstrate a combination of normal and strike-slip motion, influencing the formation of both the Vatera and Lesvos Basins. This study confirms that the region's seismicity and basin evolution are heavily influenced by a complex interplay of strike-slip and extensional tectonics, providing insights into the broader seismic and geological processes governing the North Aegean region.

ABSTRACT. Lesvos island, located on the Northeast Aegean region, Greece, is characterized by active tectonics associated with the evolution and deformation of the broader Northeast Aegean Sea. The Northeast Aegean region is characterized by complex tectonics controlled by interplay of moving tectonic plates in the broader area. The area is affected by the dextral strike-slip movement of the North Anatolian fault, which ends in the Aegean basin and creates significant tectonic structures such as the North Aegean trough and the Skyros trough. The area is also affected by E-W trending normal faults. Several studies show that the region of the Northeast Aegean region is characterized by complex transtensional stress pattern due to the influence of the NAF, which in combination with the N-S extension stress field of the Aegean micro-plate, creates several secondary faults. (Pavlides & Caputo, 1994; Bellier et al., 1997; Kiratzi, 2002; McNeill et al., 2004; Chatzipetros et al., 2013; Konstantinou, 2017; Sakellariou et al., 2017). Except from the well-developed NE-SW faults, the reflection profiles also show the existence of E-W and NW-SE oriented faults which were interpreted as Riedel fractures resulting from the transtensional character of the stress field (Pavlides & Tranos, 1991; Chatzipetros et al., 2013; Konstantinou, 2017). The tectonic structure of Lesvos Island, both offshore and onshore, is similar to the overall regional deformation of the North Aegean area, where the two main strands of the western prolongation of the North Anatolian Fault form the North Aegean and the Skyros basins. In the Northeast Aegean region there are several E-W trending normal faults due to the active N-S extension stress field, but also there are several other strike-slip faults which are compatible that created in combination of the North Anatolian Fault that pass very close to Lesvos Island. These strike-slip faults have primarily NE-SW orientation and secondarily a NW-SE orientation (Chatzipetros et al., 2013; Kiratzi, 2018; Nomikou et al., 2021). The neotectonic studies in Lesvos Island have identified and mapped the major active tectonic structures of the island which are both normal and strike-slip strike (Zouros et al., 2008; Chatzipetros et al., 2013, Mourouzidou, 2021). In the area of west Lesvos there is a gap in tectonic data, due to the lithology which make difficult to identify fault traces. Since the relief is directly affected by erosional processes, among other factors, its intensity is associated with the age of faulting: younger activity generally produces steeper relief. Therefore, geomorphic structures associated with faulting are indicative of relatively recent age (Chatzipetros et al., 2013). Intense volcanic activity appeared on Lesvos Island during Lower Miocene (23.5 to 16 million years ago) and the volcanic rocks are covering the 2/3 of the island’s surface. Several volcanic rock units have been identified (Pe-Piper and Piper, 1993). West Lesvos is covered mainly by pyroclastic material of the Sigri pyroclastic formation (Pe-Piper et al, 2019). Pyroclastic formations are easily eroded and thus the geomorphological indicators related with the recent tectonic activity are not well-preserved in the relief. Extensive field work was carried out for the study of tectonic structures in order to identify the tectonic deformation in the broader area, according to the new data. Our study was based on the observations of the fresh road cuts created due to public works for the reconstruction of the new Kalloni – Sigri road. Lots of new tectonic data in the area of West Lesvos, were revealed. The fault planes affecting the volcanic formations consist significant indicators for the tectonic deformation in the area.

ABSTRACT. Groundwater and surface water nitrate pollution constitute an important environmental issue worldwide. The primary source of nitrate pollution is usually human activities, particularly in regions heavily influenced by agriculture and livestock farming (Kazakis et al., 2020). In numerous aquifers across Greece, nitrate concentrations exceed the maximum permissible limit for drinking water (50 mg/L), raising significant concerns due to their potential adverse impacts on human health (Daskalaki and Voudouris, 2008). This research was conducted in a Mediterranean region affected by nitrate pollution where the groundwater originates from porous, karsts and fractured rock aquifers. This study is focused on the administrative boundaries of DEYA Oraiokastrou due to the elevated concentrations of nitrate in drinking water. The determination of nitrate origin and regime in the porous aquifer is of utmost importance in order to map the polluted aquifer layers and locate zones with nitrate concentration below the permitted drinking limit (50 mg/L).

ABSTRACT. Malliara Hill, located north of Vilia in Attica, Greece, is part of the Pelagonian Unit, featuring Upper Paleozoic and Triassic formations. It comprises two overlapping thrust sheets above a relatively autochthonous sequence, with the upper sheet and autochthonous series forming karstified carbonate aquifers. An impermeable layer of Permian-Triassic clastic rocks separates these carbonate sequences. Two springs at the tectonic boundary between the teo thrust sheets discharge water from the upper carbonates, shaped by a turtle shell-like thrust fault, and rely on precipitation for recharge. The carbonate formations of the autochthonous sequence are ideal for investigating groundwater resources to meet local water supply and irrigation needs.

ABSTRACT. The epikarstic zone near the Holy Monastery of Kleiston is a 10-meter-thick layer of the lower carbonate series noted for its high porosity and permeability. This porosity results from the dissolution of carbonate rocks by CO2-rich water and the presence of multiple fracture systems and low-angle faults. The recharge of this epikarst occurs through precipitation and lateral seepage from surrounding geological formations, indicating a dual (allogenic and autogenic) recharge mechanism. In the wet season, infiltrating precipitation and meltwater percolate through fissures into the deeper layers of the lower carbonate series, while some water remains in the epikarst, forming a perched aquifer. The two low-angle faults facilitate lateral groundwater flow, leading to epikarstic springs in nearby caves. This discharge is the cause of water influx and the manifestation of moisture within many of the buildings of the Holy Monastery of Kleiston. This study highlights the overall importance of the epikarst zone in the collection and flow of water infiltrating karst formations, particularly emphasizing its critical role in the hydrogeological conditions of the area surrounding the Holy Monastery of Kleiston. Its impact on water influx and the manifestation of humidity is complex and is influenced by morphological, lithostratigraphic, tectonic, and climatic factors

ABSTRACT. It is crucial and necessary for investigation into the vulnerability of aquifers, which are groundwater resource systems. Throughout the research area, aquifer formations are still in risk from pollutants that are both naturally occurring and caused by humans. The results of six distribution maps, which correspond to the six parameters of the DRASTIC methodology contributed to the drafting of the final DRASTIC map that indicates the distribution of its vulnerabilities study area in terms of external pollutant. The maps were produced using the ArcGIS Pro program as well as the value of the gravity of each parameter. According to the final vulnerability map almost completely the SW part of the watershed it appears in green as the least sensitive part of the study area. This is reasonably explained as this section characterized by a large depth of the aquifer, high slopes, low rainfall and clay material that is impermeable, preventing the infiltration of the pollutant. Instead, highly vulnerable positions within it defined area are in red in the NW part of it, on both sides of the Kalogria lagoon, and in some places in the central part of the basin, which are characterized by gentle slopes, shallow depth of groundwater, intense rainfall and the presence of karstic limestone. The above features favor active recharge and the infiltration of pollutants. Finally, the other areas in the central and NW extent of the study area are characterized by high to moderate vulnerabilities as well present intermediate characteristics. Due to its ability to adapt to specific hydrogeology and human (land use) factors, this model-based technique can be used to study and manage groundwater resources. The pollution hazard map provides the data sets and model predictions required for land use and water resource management and strategic planning.

ABSTRACT. The contact spring “Kefalari Agios Ioannis” discharges the karst aquifer that develops in the platy limestones (Ks-Pc.k) of the Pindos Unit at their contact with the underlying and impermeable red cherts, siltstones and “First Flysch” (Js-Ki.fl) of the Pindos Unit. The clarification of the hydraulic characteristics of the karst aquifer, through the “Kefalari Agios Ioannis” spring, is of immense importance for the sustainable management of water resources in the broader area of Dimitsana, which is continuously developing in terms of tourism. Additionally, the operation of the Open-Air Water Power Museum of the Piraeus Cultural Foundation, which is located immediately downstream of the spring, is inextricably linked to the functioning of the “Kefalari Agios Ioannis” spring. The recession coefficient of the “Kefalari Agios Ioannis” spring calculated from the flow measurements which were conducted from 14-07-2024 to 27-10-2024 is 8.69×10-3 days-1, which means that the water flows through the fractures and the intra-stratigraphic voids of the platy limestones (Ks-Pc.k) of the Pindos Unit. The aforementioned calculated value is consistent with the literature data for the recession coefficient of karst aquifers developed in the Pindos Unit and in equivalent units, which is on the order of 10-3 days-1 (Soulios, 1985; Giannatos, 1999; Karalemas, 2010).

ABSTRACT. Introduction The Kefalonia-Ithaca UNESCO Global Geopark (UGGp) consists a distinct geographical area renowned for its remarkable geological features, valuable ecosystems, unique cultural identity, and traditional ways of life. The Kefalonia-Ithaca UGGp is characterised by its intense seismic activity due to its geotectonic position, which is one of most tectonically active regions in Europe. Another defining feature of the geopark is the pronounced karstification, caused by water dissolving the limestone that covers most of the two islands’ surfaces. This unique combination of widespread limestone, tectonic activity, and climatic conditions has led to the formation of numerous karstic features, both underground and on the surface, such as caves, sinkholes, dolines, and poljes. The richness of the natural and cultural heritage of the two islands due to its geological wealth makes the territory of Kefalonia-Ithaca UGGp a unique territory, whose structured approach will strengthen its knowledge, the importance of its functions, and its tourist, heritage, and cultural potential. Kephalonia-Ithaca UGGp constitutes a territory that promotes the sustainable development of its region by leveraging their unique geological heritage, natural landscapes, and cultural traditions. Several actions are specifically designed to highlight the area’s rich geological heritage, aligning closely with the United Nations Sustainable Development Goals (SDGs). Below there is an overview of the typical actions Kefalonia-Ithaca UGGp takes to achieve these goals: 1. Education and Awareness One of the primary goals of the Kefalonia-Ithaca UGGp is to provide educational programs regarding the different aspects of the natural and anthropogenic environment, aiming to inform, raise awareness, and foster a deeper connection with the region. Particularly there are several educational programs specifically designed to showcase its rich geological heritage. These initiatives play a vital role in advancing the sustainable development of the region. Additionally, the curated exhibitions at the Koutavos Lagoon Information Center and in Anogi village serve as outstanding educational resources, offering engaging and informative experiences for visitors. The educational programs (Figure 1) which focus on geological heritage include the following:

• The Kefalonia-Ithaca UGGp has developed a school programme specifically for geodiversity, named “Identification and protection of the geological heritage of the Kefalonia-Ithaca Geopark” for all school classes. • A newly developed educational package concerning the fossils of the geoparks. This educational package presents to the children how life, landscapes, and climate have changed over time and how living things responded to those changes. The educational package consists of a worksheet, educational games for children of different ages that can be played both indoors and outdoors plus other activities all included in a dedicated museum box containing also actual fossils and replicas. • Caves in Kefalonia-Ithaca • The links Between Biodiversity & Geodiversity in the Aenos National Park • Earthquakes in Kefalonia-Ithaca UGGp • Finally, 10 3-minute videos have been created with the theme of the presentation and interpretation of geological phenomena and structures (deltas, geological evolution of Kefalonia, volcanoes, sinkholes, “menirs” (monoliths), earthquakes, caves, Poros gorge, Ithaca “Fjords”, Rudists).

The involvement of the local community is very important. Partnering with schools, universities, and community groups can help foster a deeper appreciation and understanding of local heritage. Such initiatives not only cultivate pride in the community but also strengthen social bonds and contribute to reducing emigration. The Educational programs of Kefalonia-Ithaca UGGp are very well developed. Especially, the high number of visits proves their success. In total, 2,708 pupils and 143 teachers have visited the two environmental centers of Kefalonia-Ithaca geopark, since 2022. The participation of schools and the local community in the educational excursions is also remarkable.1. Research and Innovation Kephalonia-Ithaca UGGp recognizes the importance of the collaboration with academic institutions for research on geology, biodiversity, and cultural history, in order to achieve the public awareness of understanding the Earth processes, as well as the links among all these aspects. For all these reasons, the Geopark collaborates with the local institutions, universities, as well as with the Department of Geology of the University of Patras, in order to develop sustainable practices. Recent projects have focused on studying and promoting the palaeontological heritage of the Geopark, enhancing scientific understanding and attracting geotourism. For this reason, the Department of Geology of the University of Patras implimented the project “Study and exploitation of the paleontological heritage of the Geopark of Kefalonia and Ithaca” (Iliopoulos et al., 2024). Another project that the University of Patras has taken over is “The Possibilities of exploitation of clay outcrops for mud therapy” (Botziolis et al., 2024) (Figure 2). Additionally, the University of Patras implemented a geotechnical study on the Restoration of the Mycenaean Cemeteries in Mazarakata – Lakithra (Zelilidis et al., 2023). It is very important also that the results of the three projects have already been published in international scientific journals. Another project implemented by the Kefalonia-Ithaca UGGp is BIO-MEMORY, a project about the Memorial Olives and olive trees including recording, imprinting, dating and promoting them as high value ecosystems, funded by Ionian Islands Region. Furthermore, BIONIAN is another project which includes actions to protect & promote biodiversity in the Ionian Islands Region, funded also by the Ionian Islands Region and by the Ionian University, supervised also by the Geopark. A different project, LAERTIS, consists of an innovative management system for natural disasters management in the Ionian Islands Region funded and implemented by Ionian Islands Region, the Ionian University, University of Athens and the Technical chamber and of course it is also supervised by the Geopark. Finally, a recent project that the University of Patras is responsible for concerns the setting up of a proposal for the development of three caves as sheaves in the wider area of Sami Municipality and their connection to the existing speleological park of the Municipality. 1. Research and Innovation Kephalonia-Ithaca UGGp recognizes the importance of the collaboration with academic institutions for research on geology, biodiversity, and cultural history, in order to achieve the public awareness of understanding the Earth processes, as well as the links among all these aspects. For all these reasons, the Geopark collaborates with the local institutions, universities, as well as with the Department of Geology of the University of Patras, in order to develop sustainable practices. Recent projects have focused on studying and promoting the palaeontological heritage of the Geopark, enhancing scientific understanding and attracting geotourism. For this reason, the Department of Geology of the University of Patras implimented the project “Study and exploitation of the paleontological heritage of the Geopark of Kefalonia and Ithaca” (Iliopoulos et al., 2024). Another project that the University of Patras has taken over is “The Possibilities of exploitation of clay outcrops for mud therapy” (Botziolis et al., 2024) (Figure 2). Additionally, the University of Patras implemented a geotechnical study on the Restoration of the Mycenaean Cemeteries in Mazarakata – Lakithra (Zelilidis et al., 2023). It is very important also that the results of the three projects have already been published in international scientific journals. Another project implemented by the Kefalonia-Ithaca UGGp is BIO-MEMORY, a project about the Memorial Olives and olive trees including recording, imprinting, dating and promoting them as high value ecosystems, funded by Ionian Islands Region. Furthermore, BIONIAN is another project which includes actions to protect & promote biodiversity in the Ionian Islands Region, funded also by the Ionian Islands Region and by the Ionian University, supervised also by the Geopark. A different project, LAERTIS, consists of an innovative management system for natural disasters management in the Ionian Islands Region funded and implemented by Ionian Islands Region, the Ionian University, University of Athens and the Technical chamber and of course it is also supervised by the Geopark. Finally, a recent project that the University of Patras is responsible for concerns the setting up of a proposal for the development of three caves as sheaves in the wider area of Sami Municipality and their connection to the existing speleological park of the Municipality.

ABSTRACT. To foster geotourism and raise awareness among both visitors and the local community, the Vikos-Aoos Geopark launched the project "Enhancement of Geosites and Geological Formations and Evaluation of Visitability of Geosites and Landscapes of High Aesthetic Value in Vikos-Aoos Geopark" in 2022. This initiative, which runs through 2024, encompasses three main components. First, an innovative mobile app was developed to enrich the Geopark’s information and interpretation services. The app, available both at visitor centers and on mobile devices, offers a comprehensive collection of resources on the region’s geological, natural, and cultural heritage. This includes texts, photographs, 360-degree imagery, and videos, presenting a cohesive and detailed narrative. Additionally, information centers were established in buildings provided by the two municipalities within the Geopark, offering visitors an in-depth understanding of the area’s significance. Second, outdoor viewing platforms were constructed at strategic sites to highlight the Geopark's most remarkable geosites and aesthetically valuable landscapes. Three high-traffic locations were selected, where aerial photography was used to showcase geological features that may not be visible from the ground, offering visitors a more extensive view of the park’s natural beauty. Third, a visitor tracking system was implemented across eight key sites along major hiking trails that either begin or pass through notable geosites. These sites include the Dragon Lakes of Smolikas and Tymfi mountains, the Voidomatis springs, and the Vikos and Aoos gorges. This new system has provided valuable data on visitor numbers and seasonal trends, offering a clearer understanding of geotourism dynamics within the geopark.These efforts have established a strong foundation for sustainable tourism development in the Vikos-Aoos Geopark. By incorporating modern technologies and enhancing infrastructure, the project has significantly improved the visitor experience while increasing awareness of the area’s unique geological and cultural heritage. Furthermore, the visitor data gathered has laid the groundwork for future planning and management, ensuring that tourism growth is aligned with the region’s conservation objectives. This project serves as a potential model for other regions seeking to balance tourism development with the preservation of their natural and cultural resources. Acknowledgements We would like to thank Natural Environment and Climate Change Agency (NECCA) for founding the project.

ABSTRACT. The Lavreotiki UNESCO Global Geopark comprises one of the nine Greek UNESCO Geoparks, promoting the significant geological heritage of Greece. It is the only geopark located close to Athens, the capital city of Greece and bears a long and rich mining history. Lavreotiki Geopark occupies the southeastern part of the Attica Prefecture and its spatial extent coincides with the region of the Lavreotiki Municipality. Although, mining heritage represents the core of the Lavreotiki Geopark, other geological features such as coastal, geomorphological landforms enclose high scientific and educational value, revealing unknown aspects of this deep-in-time heritage. The Lavrion mining district covers an area of >100 km2 and has been exploited nearly continuously for silver (Ag) and lead (Pb) from 4000 BC until the late Roman times (Conophagos, 1980; Rosenthal et al., 2012). It is also considered that Lavrion was a source of copper (Cu) for a large part of the latter period (Gale et al., 2009; Kayafa, 2020). Monumental sites and structures such as the Industrial District, as well as the Thorikos theater at the flanks of the Velatouri hill, reveal the inseparable connection of the ancient local people with their peculiar local geology. This type of geology provided the appropriate resources to the Athenian Democratic Polis to be transformed during the Classical period and fund the trireme fleet, which determined the naval battle at Salamis against the Persians. Apart from this mining wealth, the Lavreotiki Geopark includes a 73-km long coastline, hosting a rich geodiversity and biodiversity. With the aim of assessing the impact of the future sea level rise on the coastal landforms, which can also be potential future geosites, the geopark’s personnel undertook an extended project between 2022-2024 for surveying and mapping the geological/geomorphological sites on the coastline. During these activities at the Kaki Thalassa Bay (Keratea, Lavrion), a small rocky islet was surveyed (Fig. 1). This islet consisting of Pounta marble, is located 128 m from the closest coast and hosts two strange pool-like structures at its eastern side (Fig. 2). These morphological structures were considered to be the result of natural processes and were often referred as natural pools. On the contrary, detailed geomorphological mapping with the application of drone-assisted technology and S-f-M (Structure-from-Motion) technique in combination to geological observations, resulted in anthropogenic pseudokarst features in the sense of Veress (2022). The assessment of the origin of these pools was implemented with the use of sophisticated, low-cost, non-destructive photogrammetrical technique, employing two-dimensional (2D) aerial mapping and geological-geomorphological field-based observations. The same technology has been applied in other locations of the geopark (Kampolis et al., 2024) as well as in other sites of interest (Kampolis et al., 2021) with valuable results.

The followed methodology was arranged in two separate phases. The first phase included the aerial 2D mapping and the photogrammetry of the small islet and the second one comprised the in-situ geological and geomorphological observations, as well as the extraction of samples for subsequent analysis. During the first phase of the project, a DJI Mavic Air 2 drone was employed for the 2D mapping of the islet, after setting up its flight mission within the Copterus app, running on an “iphone 13 mini” mobile phone. The drone’s flight was programmed at an altitude of 30 m with a 75% frontal and lateral overlap, yielding a total (real) flight duration of 13 min. The collected aerial photos were then inserted in Agisoft Photoscan Pro software and following the photogrammetrical work-flow without ground control points, the three-dimensional (3D) reconstruction of the small islet was generated (Fig. 3). The Agisoft work-flow includes certain stages of multi-image processing: A) photos alignment, B) point cloud building, C) mesh reconstruction and D) Digital Elevation Model (DEM) generation (Semaan and Salama, 2019). For the in-depth exploitation of the islet’s 3D reconstruction, the exported mesh file from Agisoft was input in CloudCompare software and converted into a point cloud for further geometric measurements. The latter enables various measurements such as inclinations, azimuths, lengths, areas and geometrical features of plane surfaces (dip and dip direction) on certain features. The second phase consisted of the mineralogical observations on mineral assemblies found on the perimetry of these pool-like structures. Also, geomorphological observations on the morphology of the pools took place in-situ. The depths of their bottom were measured with a SUUNTO D3 digital depth gauge (accuracy ±0.1 m). The generated 3D model of the small islet in combination to the field-based geomorphological measurements, provided the ability to assess the formation origin of the pools, present at the eastern side of it. According to the geomorphology of the coastal part of the islet and the bathymetry of the pools’ bottom, it is unlikely for the pools to be the result of natural erosional processes. This can be supported by the bathymetry of the connection passage between the open sea and the easter pool (Fig. 4). The depth at this point reaches only 0.3 m and thus prevents the wave activity and its subsequent erosive force to enter the eastern and western pool and form them, as the erosive force is consumed on the shallow coastal part. Additionally, the eastern pool reaches a depth of 2.5 m, which cannot be justified by natural processes (i.e. waves, karstification).

Moreover, the presence of a tectonic structure trending NW-SE (15o/204o – Dip/DipDir) and crossing the western part of the islet (Fig. 2) may be an extension structure related to the Miocene low-angle detachment fault developed during the top-to-SSW crustal extension, resulting in the Western Cycladic Detachment System (Loisl et al., 2014), and locally referred as the South Attic Detachment (SAD) (Ross et al., 2021). This fault seems to play a role on the presence of sulfide mineralization (now oxidized to iron oxides), recorded on the periphery of the pools and along its surface (Fig. 5). The oxidized mineralization occurs above the SAD, where it replaces, and also cements brecciated fragments of the Punta marble. Ross et al. (2021) mentioned that normal faults rooted within the SAD are linked to its movement and have hydrothermally affected the Pounta marble. Consequently, it is possible that this NW-SE fault has designated the oxidized sulfide mineralization on the Pounta marble of the islet, which also attracted the interest of the ancient people. The latter must have started exploiting this mineralization, leaving open depressions that were later inundated by the sea level rise since the antiquity. Ancient miners extracted the mineralized layer, and this is probably the reason for the flat, shallow bottom of the western pool. The pool was excavated for the extraction of the mineralization, whereas natural processes like karstification would have resulted in a more uneven bottom. Therefore, these depressions originated by the anthropogenic activity on the carbonate rock of the islet, can be falsely interpreted as karst landforms and thus, represent the so-called anthropogenic pseudokarst. The nature of the latter revealed these previously unidentified ancient mining works.

ABSTRACT. Introduction The purpose of this work is to study the specifications required for developing or improving a quality label for products and services offered by businesses in the regions of the four collaborating geoparks (Vikos-Aoos UNESCO Global Geopark, Sitia UNESCO Global Geopark, Chelmos Vouraikos UNESCO Global Geopark, Psiloritis UNESCO Global Geopark). The project involves the design of a special label for local agrotourism products and services in the cooperating areas, based on global market quality standards and UNESCO principles for Global Geoparks. Additionally, it includes the design of the specifications and evaluation criteria for the products and services of each region, which will carry this special label, in alignment with UNESCO's principles for Global Geoparks. This expertise is conducted within the framework of the Interterritorial Cooperation Plan entitled "EMPOWERMENT, PROMOTION, AND NETWORKING OF UNESCO GEOPARKS" and, more specifically, as part of the project "Expertise on Specifications – Evaluation Criteria and Design of a Special Label for Local Agrotourism Products and Services."

Fig.1: Presentation of the project partners

The Interterritorial Cooperation Plan is implemented under the local CLLD/LEADER program, Submeasure 19.3 of Measure 19 of the Rural Development Program (RDP) 2014–2020, by the coordinating Local Action Group (LAG) ACHAIA S.A. – DEVELOPMENTAL ANONYMOUS COMPANY OF LOCAL AUTHORITIES, in collaboration with the following participating partners: EPIRUS DEVELOPMENTAL S.A. – Developmental Organization of Local Authorities, LASSITHI DEVELOPMENTAL S.A. – Developmental Organization of Local Authorities, AKOMM – PSILORITIS DEVELOPMENTAL S.A. – Developmental Organization of Local Authorities (Fig.1).

Methodology The design of the quality label and the proposals for improving the existing ones (Psiloritis and Sitia UGGps) were based on several aspects: • Study of Criteria and Application of 1st Generation Quality Labels: Examination of standards like AGRO (Hellenic Agricultural Organization–DIMITRA) and the EU's Eco-Label for environmental certification of products and services. • Study of 2nd Generation Quality Labels: Investigation on labels such as the certification for the Samaria National Park, the "CRETE" quality label, local cultural support agreements like the Epirus Ancient Theaters Cultural Route, the PINDOS quality pact (no longer in effect), and the Special Quality Label for Greek Cuisine (E.S.P.E.K.). • Study of Quality Labels for Geoparks: Analysis of existing labels from participating geoparks (Sitia and Psiloritis) and international geopark labels such as “Naturtejo Geopark Geoproduct,” “Qualità parco” from Adamello Brenta Geopark, and “Naturally Tasty” from Beigua Geopark. • Study of GEOfood Label Standards: Inspection of the guidelines and specifications of the GEOfood label. • Review of Literature including research on the history and philosophy of quality label development, as well as other public surveys (e.g. Ilbery and Kneafsey, 1998; Henchion and McIntyre, 2000; Eckardt, 2007; Marques, 2007; Carpenter and Larceneux, 2008; Lorenzini, 2011; Ramos and Garrido, 2014; Košičiarová Kajima et al., 2016; 2017; Hutagalung et al., 2024 and other). • Discussions with Project Partners and Geopark Representatives Five online meetings were held, including one kickoff meeting and four individual meetings with each partner. These meetings focused on expectations and challenges regarding quality label use. • Online meeting with Lassithi Developmental S.A., Sitia Geopark, and Local Businesses: Local businesses shared their experiences, challenges, benefits, and suggestions for improving the label's operation. A survey conducted by the Psiloritis Geopark also provided insights from businesses using its quality label. • Contractor’s experience and discussions with local businesses and geopark representatives • Designing of a customized questionnaire (Google Forms) aiming on a) obtaining general information about the participating businesses, information about the promotion methods and sustainable practices they use and information about their level of knowledge about geoparks and quality labels in general and b) in assessing the intentions of geoparks that do not implement certification as well as to evaluate the experiences of already certified businesses. The questionnaire was distributed to relevant businesses in all four areas and the results were analysed and validated. An analysis of the needs of the co-operating partners was also conducted.

Results The research resulted in proposals regarding the improvement of the already existing quality labels and the drafting of a regulation which sets out the conditions that must be followed by beneficiaries who wish to use this quality mark. The aim of granting this quality mark is to certify the suitability of the product-service to represent the geopark area as a genuine expression of its identity. Additional objectives for applying the quality mark to products and businesses are: • To certify the locality of the product-service • To create added value to the product-service by providing or enriching the identity of the region and leveraging participation in the UNESCO Global Geoparks Network • To connect the products-services with the geodiversity elements of the geopark area • To provide differentiation to the products-services in relation to similar products by leveraging the uniqueness of the region and the experiences provided • To enhance the credibility of the product/service • To promote local products-services at a national and international level • To strengthen relationships between producers, entrepreneurs and other interested parties • To ultimately strengthen the local economy either directly or indirectly. • To enhance the feeling of "belonging" in the collaborating businesses The quality mark is aimed at businesses related to agro tourism, agriculture and rural tourism.

Eligibility criteria The eligibility criteria are divided into general criteria, specific criteria and proportional coverage criteria. The general criteria are applied in their entirety to all enterprises and regard the legality, locality and mode of operation of the enterprise. The specific criteria are applied per type of enterprise (catering and accommodation businesses, manufacturing businesses -inside or outside the geopark area-, tourist-ecotourism offices, use of organic products etc.). The proportional coverage criteria constitute a set of criteria, the application of which can substantially contribute to the achievement of the objectives of the certification but are more specialized and difficult to apply practices (e.g. ISO or other certifications, minimizing the consumption of natural resources and waste in at least one way etc). For this reason, it is not recommended to cover all of these criteria, but it is required to cover at least 5 of them. The coverage of the required criteria is confirmed by the presentation of the corresponding supporting documents.

Code of conduct The "identity" of a region is not shaped solely by measurable characteristics, and for this reason, granting the current certification requires, in addition to meeting specific criteria by the interested businesses, a commitment to a set of ethical rules. This involves a collection of principles and rules that the parties involved must fully adopt as a way of life. These cannot function as criteria because their evaluation by individuals is inherently subjective. The signing of a Code of Conduct is proposed as a way to operate with integrity and commit to common values.

The proposed quality label regulation also determines obligations of both the participating businesses and geoparks, as well as of the certification process (application, evaluation, inspections and audit, issuance and monitoring) and proposes actions in order to maximize the impact of the quality label.

Discussion and Conclusions The establishment of a quality label for geopark products and services represents a significant step towards promoting sustainable development and the responsible management of natural and cultural resources. Through this initiative, the high quality of offered products and services is ensured, while simultaneously the visibility of geoparks as exemplary areas that integrate tourism, education, and environmental protection os enhanced. The implementation of the quality label can make a crucial contribution to the economic development of local communities by offering incentives for innovation while protecting and showcasing the unique natural wealth of geoparks. Strict adherence to the criteria established for the quality label will guarantee its reliability and strengthen the trust of visitors and consumers. Finally, collaboration among various stakeholders—such as local communities, producers, management bodies, and educational institutions—serves as the foundation for the successful implementation and continuous improvement of the quality label. This will enhance the sustainability and uniqueness of geoparks in the long term.

References Carpenter, M., Larceneux, F., 2008. Label equity and the effectiveness of values‐based labels: an experiment with two French Protected Geographic Indication labels. International Journal of Consumer Studies, 32(5), pp.499-507. Journal Article Eckardt, C., 2007. Creating economic benefit by regional and international networking in the Global and European Geopark Bergstrasse-Odenwald, Germany. Abstracts of 7th European Geopark Network Open Conference, NW Highlands Geopark 10, Conference Procceedings Henchion, M., McIntyre, B., 2000. Regional Imagery and Quality Products: the Irish Experience. British Food Journal, 102(8), 630-644, Journal Article Hutagalung, P.M., Nasution, Z., Ginting, N., 2024. The role of geological relationship and brand of geoproduct on regional development in Samosir Island of Geopark Caldera Toba with mediating method. GeoJournal of Tourism & Geosites, 52(1), Journal Article Ilbery, B., Kneafsey, M., 1998. Promoting Quality Products and Services in the Lagging Rural Regions of the European Union. European Urban and Regional Studies, 5(4), 329-341.Journal Article Kajima, S., Tanaka, Y., Uchiyama, Y., 2017. Japanese sake and tea as place-based products: a comparison of regional certifications of globally important agricultural heritage systems, geopark, biosphere reserves, and geographical indication at product level certification. Journal of Ethnic Foods, 4(2), 80-87. Journal Article Košičiarová, I., Nagyová, Ľ., Holienčinová, M., Rybanská, J., 2016. Quality Label as the Guarantee of Higher Quality of Food–A Case Study of Slovak Food Market. Procedia-Social and Behavioral Sciences, 220, pp.200-209. Journal Article Lorenzini, E., 2011. Territory branding as a strategy for rural development: experiences from Italy. Journal Article Marques, R. T., 2007. Sustainable tourism and certification in Geopark Naturtejo: A case study. Paper presented at 7th European Geopark Network Open Conference, HighLands Geopark, NW.Conference Procceedings Ramos, E., Garrido, D., 2014. Towards a" 2nd Generation" of Quality Labels: a Proposal for the Evaluation of Territorial Quality Marks. Cuadernos de desarrollo rural, 11(74), pp.101-123. Journal Article

ABSTRACT. This study undertakes a comprehensive assessment of karst landforms within the Grevena-Kozani UNESCO Global Geopark, focusing on scoring and analyzing the area&#39;s speleological features. By applying six evaluation criteria—scientific, ecological, cultural, aesthetic, economic, and potential utilization—previously used in Crete’s Psiloritis and Lasithi Mountains (Fasoulas et al., 2011), the study employs a multidisciplinary methodology to explore management prospects for these unique landforms. It also aims to promote sustainable use and geoconservation of the geopark’s caves, aligning with principles advocated by the European Geoparks Network and the International Union for Conservation of Nature (IUCN).

ABSTRACT. Urban geotourism is a growing field that focuses on the exploration and appreciation of geological features and geocultural heritage within urban environments. It bridges the natural and human-made worlds by highlighting the geological significance of urban landscapes while incorporating historical, cultural, and mythological narratives. As Del Lama (2018) defines, urban geotourism involves visiting sites within city boundaries that are connected to geological concepts and features, whether these are purely natural formations or modified by human intervention. Geotrails play a central role in this context by offering structured routes that connect points of geological, cultural, and historical interest. On the other hand, geomythology, the study of how natural geological phenomena inspires myths and legends, provides a fascinating lens through which to explore the relationship between human culture and the Earth’s dynamic processes. By examining the interplay of geological events and ancient narratives, geomythology offers insights into how early civilizations interpreted and mythologized their environments. In the context of urban geotourism, geomythology enriches the exploration of geosites by connecting scientific interpretations with cultural heritage. The purpose of this study is to create a geotrail in order to promote awareness and appreciation of the geological and cultural heritage of the Attiki Region, highlighting the connections between natural processes and human history. It aims to present geological concepts in an accessible and engaging manner, fostering environmental awareness and encouraging sustainable tourism practices. The geotrail also offers an alternative perspective on Athens’ urban and natural landscapes, combining geological diversity, historical narratives, and geomythological interpretations.

ABSTRACT. Important subduction zone processes are exceptionally well displayed on Syros. The island is famous for its abundance of rare metamorphic rocks, notably blueschists and eclogites, and striking evidence of strong deformation. Glaucophane was first discovered in Syros in 1845, long before this beautiful mineral was recognized as a key witness of high-pressure metamorphism. Since the 1970s, numerous researchers from all over of the world have worked in the Cyclades to understand their complex tectonic evolution. The current understanding of how subduction zones work has been substantially improved by studies in Syros. However, outside the academic world, hardly anyone knows about these important results. The Syros GeoPark project aims to change this, to make people aware of what Syros has on display, what fascinating story the rocks can tell them and what wealth such geology offers. The Syros GeoPark can raise the pride and identification of locals with their island, helping conservation efforts. Beyond educational goals, the aim is to develop sustainable forms of tourism with low environmental impact and prolonged seasons. Attracting geo-tourists to Syros should serve economic and ecological goals equally, for the benefit of many.

ABSTRACT. Abstract

The Environmental Seismic Intensity Scale (ESI 2007), introduced by the International Union for Quaternary Research (INQUA), represents a groundbreaking approach for quantitatively assessing macroseismic intensities. This scale, comprising 12 levels, focuses on the environmental impacts of earthquakes, such as surface ruptures, tectonic uplifts, landslides, liquefaction, and hydrological changes. Unlike traditional macroseismic scales, which emphasize anthropogenic damage, ESI 2007 relies exclusively on physical observations, eliminating uncertainties linked to socioeconomic and cultural factors.

This study employs a systematic methodology, integrating geological observations, historical records, and seismological data within a GIS framework to analyze the environmental, geomorphological, and socioeconomic impacts of five significant earthquakes in Western Turkey and the Eastern Mediterranean. The analyzed events include the Marmaris (1957), Gediz (1970), Izmit (1999), Simav-Kütahya (2011), and Samos-Izmir (2020) earthquakes. High-resolution maps were generated to visualize active faults, liquefaction zones, and high seismic risk areas, highlighting the mechanisms and effects of geodynamic phenomena.

Key findings demonstrate that the ESI 2007 scale effectively captures environmental impacts, such as ruptures and ground deformation, which are often overlooked by traditional scales like the Modified Mercalli Intensity (MMI). For instance, the Izmit and Samos-Izmir earthquakes revealed significant tectonic and geomorphological changes, underscoring the scale’s utility in understanding natural processes. Conversely, the integration of ESI 2007 with MMI provides a multidimensional approach, capturing both environmental and anthropogenic impacts.

This study underscores the necessity of incorporating both ESI 2007 and MMI scales for comprehensive seismic analysis and risk management. By leveraging paleoseismological data and advanced geospatial tools, ESI 2007 offers enhanced predictive capabilities and supports long-term strategies for disaster preparedness and mitigation.

ABSTRACT. In this work, the properties and the dynamic response of the soil formations in the area of Chalandri are investigated. Its main points are the collection and synthesis of all available data from 92 sampling boreholes, the estimation of shear velocity (Vs) through empirical correlations, the 1-D dynamic analysis of soil profiles modelled from 42 borehole locations, the zonation of the area according to site response and the production of maps showing the spatial distribution of the main characteristics of ground motions (fundamental period and amplification factor). Finally, these results were correlated with the building damage caused by the 1981 earthquake in Alkyonides.

ABSTRACT. Among natural disasters, earthquakes have the most destructive potential to water pipe networks. The induced damages to the water supply can be the main reason for post seismic economical disruptions. Thus, it is of utmost importance to recognize the most vulnerable elements of the water pipe network under seismic load, in order to manage effectively prevention and post seismic actions. At the present work, we estimate the seismic resilience of the external water network - based on Balaei et al (2020) methodology - at Lagadas municipality, one of the ten largest area municipality in Greece, as a measure of the system’s ability to absord a shock when occurs and to recover quickly after that (Bruneau, 2003). The results can be used to rank the prevention actions necessary to reduce earthquake consequences to water network performance.

ABSTRACT. Natural disasters and especially earthquakes in seismically active areas such as Greece, constitute the most significant risk that threatens tangible cultural heritage: buildings and other structures (bridges, aqueducts, etc.), archaeological and historical sites but also artifacts of everyday life, funerary objects, works of art, etc. that are kept in warehouses or exhibited in museums. The vulnerability of buildings belonging to cultural heritage is high: constructed of load-bearing masonry – a brittle material – they do not possess the structural characteristics that allow them to absorb the energy released by an earthquake, without being subject to damage and ultimately collapse. Respectively, objects placed on pedestals, shelves, in display cases or suspended from ceilings and walls, etc., under a strong earthquake run a high risk of suffering damage that is often irreversible, even when the museums themselves remain intact. In recent major earthquakes in Greece, as well as in other seismically active countries, monuments and museum exhbits were the ones that were most affected. The aim of this paper is to demonstrate the relationship between the requirement for the protection of human life, while simultaneously protecting the monumental values carried by buildings and objects that belong to cultural heritage. A case study of a building located in an area with a rich seismic history was examined, for which it was possible to collect data in order to highlight the objectives of the work. The Archaeological Museum of Rhodes was chosen, that is a building built from the island's Hospitaller Knights of St. John (1310-1522) as their New Hospital. The building was completed in 1489 and is located within the Medieval City of Rhodes, an area where data on the dynamic behavior of its soil formations is available from previous studies, while the bibliography is rich in data for the structural types and the mechanical properties of the materials of the buildings of this World Heritage Site. The seismic vulnerability of the building was studied with modern computational methods, following the provisions of the Code for interventions in buildings made of load-bearing masonry (KADET), while the stability of exhibits on pedestals was calculated with procedures proposed in the American regulation FEMA P-58 and other sources. The results of the preliminary analyzes are interesting. On the one hand, as expected, the iconic medieval building turns out to fall short of modern requirements for the seismic vulnerability of museum buildings. On the other hand, museum exhibits that are placed on the museum floors with conventional support methods (usually on pedestals that are not anchored to the floor) prove to be particularly vulnerable to earthquakes – indeed considerably smaller than those expected to cause damage to the building itself. The above results are consistent with what has been observed in recent and past earthquakes. For this reason, extensive research on this field is undergoing internationally in order to mitigate seismic risk for monuments and museum exhibits.

ABSTRACT. Storms Daniel and Elias occurred in September 2023 with only a 20-day gap between them and left a severe impact on the affected areas, since their aftermath is still clearly visible to date, 16 months later. The meteorological station in Zagora at Mount Pelion recorded the highest daily rainfall value in the country (around 760 mm) during Daniel storm, breaking the previous record of Paliki, Kefalonia (645 mm) recorded during the mediterranean cyclone Ianos in 2020 (Ντάφης κ.ά., 2023; Βουγιούκας κ.ά., 2023). Figure 1 shows the total amount of rainfall (in mm) for September over a period of ten years, as recorded by three different meteorological stations in the vicinity, namely Volos, Zagora and Makrinitsa (see Figure 4 for station locations). Studies exist already analysing the effects of these storms on various aspects of the community and ecosystem; e.g., Dimoudi et al. (2024) performed analyses to examine the effect on water quality, He et al. (2024) used SAR technologies to map effects on crops and livestock, while Mavroulis et al. (2024) highlighted all the risk factors that favor the occurrence of infectious diseases. Here, we consider effects on the built environment and infrastructures through in-situ visits. In this study we focus on the types of damage that these storms caused in the Pelion region. Through photographic documentation the damage was categorized into six key categories referring to: loss of life, damage to the road network, damage to bridges and other structural elements, soil erosion, debris accumulation, and property loss. These findings provide valuable insights into the diverse and severe impacts of storms and their effects on communities and the environment. We aim to showcase the extent of this destruction caused to the villages and communities of Pelion and provide a comparison between Pelion’s three municipalities and the types of damage each one suffered. We also point to the degree to which reparation actions have progressed at the time of writing this abstract, which is 16 months after the incident.

ABSTRACT. The demarcation of the coastline is necessary and important for the proper protection of the coastal environment and the better and faster response and management of the consequences of extreme weather phenomena that have been frequently observed in coastal areas in recent years. In this paper are briefly mentionedthe main Greek laws regarding the demarcation of the coastline (seashore). In additionthe tools used for demarcation of the coastlineare investigated and compared. Examining the various tools, the question arose whether the automatic coastline demarcation tool Shoreline Extraction Analysis and Extraction Tool (SAET) is feasible to be used for the demarcation of coastlines by a simple user. Therefore, the region of Thesprotia was chosen as a case study, and specifically a section of the coastline along the delta of the Kalamas River, the beach of Drepanos. Three events (storms) were selected that had caused disasters and flooding in the study area and with the help of the tool, the coastline was demarcated before and after each storm separately and by comparing the results we came to the conclusion that SAET could be used to identify in a timely manner the areas with problems, mainly erosion, that occur after a coastal storm.

ABSTRACT. In recent years, due to many factors, such as overpopulation, climate change, etc., the pressure for the proper management of water resources has increased and is now acquiring substantial content, setting important goals, such as the supply of sufficient quantity and appropriate quality of water, with the aim of satisfying domestic, agricultural, energy and industrial needs, both in the present and mainly in the future, the improvement of the standard of living and quality of life, the increase in the gross national product, satisfactory protection from extreme hydrological phenomena (floods, drought), etc. Water resources management is a dynamic process, aiming at the most complete possible coverage of the current needs of each use, based on rational planning, based on objective criteria and procedures. The function of water resources management includes the assessment of available water resources and the need for water (both in quality and quantity), the techno-economic and environmental investigation of projects and measures to increase available resources, along with the selection of the best options and their construction schedule (Ministry of Environment & Energy). Greece is characterized by strong spatial variability in the annual amount of precipitation, due to its physical geography. More specifically, the western part of the country is characterized by high annual precipitation levels, while the eastern part displays a smaller volume of annual precipitation, a distribution which appears uneven throughout the year, since summer is an arid period, while on the contrary autumn and winter accumulate the largest percentage of precipitation. Thus, the majority of our country's watercourses (streams, rivers, etc.) exhibit water supplies with strong annual variability (during the summer they are characterized by low to zero supplies, depending on the size of their catchment area) (E. C. Moschou, S. C. Batelis, Y. Dimakos, I. Fountoulakis, Y. Markonis, S.M. Papalexiou, N. Mamassis, and D. Koutsoyiannis, Spatial and temporal rainfall variability over Greece). Furthermore, Greece is characterized by sudden flood water supplies, which are the result of rapid rainfall, with devastating consequences in the catchment areas, due to which the importance of executing hydrodynamic and hydraulic projects in the catchment areas arises. These hydrodynamic and hydraulic projects achieve a reduction in both the intensity and the extent of the erosion and erosion occurring in the catchment area, with the result that they constitute major infrastructure projects, since they prevent the occurrence of flooding phenomena or at least limit their effects. All of the above, transform the issue of the optimal utilization of the country's water resources into a particularly complex problem. The state, aiming to address the impacts caused, has instituted new rules concerning the demarcation of streams, construction and arbitrary buildings located next to streams, with the aim of protecting water resources and floodproofing the structures that exist in the areas through which they pass. Today, in every urban planning study for the inclusion or expansion of areas in a city plan, the definition of stream protection zones is required, while for areas that are outside the plan, the construction of any structure at a distance of less than 20 meters from a stream is prohibited. Studying the river of the settlement of Petra in Lesvos, a hydrological study is prepared, estimating the peak flow at the outlet of the watershed, which is caused by rainfall with a specific return period (50, 100, 1000 years are considered). For this purpose, the rainfall curves of Directive 2007/60/EC of the General Secretariat of Water for the Kalloni area (Area Code 657) were used. The delimitations, final and provisional, that have been submitted to the Directorate of Technical Works of the North Aegean Region were collected, with the aim of creating a database, which will be updated at regular intervals, so that it is possible to find information by any interested party.