George Papathanassiou

Aristotle University of Thessaloniki | AUTH · Department of Geology (GGG)

Airport infrastructure plays a crucial role in regional and national economies, as well as during emergencies such as after major earthquakes. However, its functionality remains vulnerable to disruption caused by secondary earthquake effects, such as soil liquefaction. Hence, assess the risk posed to airport facilities by these phenomena becomes pa...

This research effort aims towards the evaluation of liquefaction susceptibility in surface geological formations to the Evros Delta river, with emphasis on the Alexandroupolis airport area, as well as, the estimation of liquefaction hazard. The evaluation of liquefaction susceptibility of the various formations in susceptibility classes utilizes g...

The 6 February 2023 earthquake doublet (Mw 7.7 and Mw 7.6) that occurred on the East Anatolian Fault Zone (EAFZ) triggered a significant amount of soil liquefaction phenomena in SE Türkiye and NW Syria. The great areal extent of the affected area and the necessity of rapid response led to the adoption and improvement of a workflow for mapping lique...

Characterization and modelling of earth processes lies in the focus of every modern approach in Earth Sciences. Concerning the variety in the nature of the processes themselves (landslides, rockfalls, earthquakes and climate changes), variability of the causing factors, differences in the extent of the effects and corresponding hazards and risks, t...

A preliminary report of mapping liquefaction phenomena triggered by the February 6 2023 M7.7 earthquake, Türkiye / Syria, based on remote sensing data. Mapping was based on optical satellite imagery (VHR Maxar imagery, Planet, Copernicus Sentinel-2 and others) and additionally Copernicus Sentinel-1 SAR & UAV orthophotos. We mapped 750 sites with li...

Medicanes, a type of strong hurricanes/cyclones occurring in the Mediterranean, can be the source of major geohazard events in Mediterranean coastal and inland areas. Medicane Ianos that hit Greece during 17–19 September 2020 caused widespread damage, with numerous landsides and floods being the most prominent. Following the landfall of Medicane Ia...

Rockfalls and landslides are a common phenomenon along the road network in mountainous areas. The aim of this work is to assess the seismic vulnerability and the probabilistic seismic risk of the road axis that connects the city of Xanthi with the Greek-Bulgarian border. Hence, cut-slope seismic vulnerability curves are generated with factor of saf...

A detailed inventory of more than 10,000 active and inactive landslides for the East Macedonia and Thrace region can provide the basis for creating inventory-based susceptibility and hazard maps for rainfall- and earthquake-induced landslides in the region (Burns & Madin, 2009; Burns & Mickelson, 2016). We plan to expand the current landslide inven...

The existence of high potential onshore and offshore active faults capable to trigger large earthquakes in the broader area of Thrace, Greece in correlation with the critical infrastructures constructed on the recent and Holocene sediments of Nestos river delta plain, was the motivation for this research. The goal of this study is twofold; compilat...

This study focuses on the delineation of liquefaction susceptibility zones in Nestos river delta (Thrace). Existence of tectonic structures capable to trigger large earthquakes in the broader area of Thrace and high potential onshore active faults in correlation with the critical infrastructures constructed on the recent and upper Holocene sediment...

We present a new complete landslide inventory for the region of East Macedonia-Thrace, Greece with more than 10,000 landslides mapped. The creation of this manually-mapped inventory was needed to overcome the limited spatial and temporal information for landslides in the region. The new landslide inventory will be used as a baseline for the calcula...

Timely and rational prediction of coseismic landslides is crucial for the design and development of key infrastructure capable to protect human lives in seismically active regions. This research introduces the novel Hybrid Coseismic Landslide Forecasting model (COLAFOS) that takes into consideration three parameters namely: The Average Slope of the...

The March 2021 Thessaly, Central Greece, seismic sequence characterized by an Mw = 6.3 mainshock and five Mw > 5.0 aftershocks triggered extensive liquefaction in the floodplain of the Piniada Valley and localized phenomena along the riverbanks of the Titarissios River. In order to document these secondary effects, we carried out immediate post eve...

This presentation describes a Web-based landslide inventory along with the generation susceptibility, hazard, and risk map for Attica Region in Greece covering a period of the last 60 years.

Landslide disasters are the result of the impacts of hazardous movement of soil and rocks that threaten vulnerable human settlements and infrastructure in cities, coasts, islands and mountains. In those areas, developments such as roads, railways, and expansion of urban areas increase exposure to the hazards of landslides (Kyoto, 2020 Commitment)....

Coseismic Landslides (COLA) are one of the most widespread and destructive hazards to result from earthquakes in mountainous environments. They are always associated with almost instantaneous slope collapse and spreading, posing significant hazards to human lives and lifeline facilities worldwide. Current methods to identify COLA immediately after...

Rockfall events consist one of the most hazardous geological phenomena in mountainous landscapes, with the potential to turn catastrophic if they occur near an anthropogenic environment. Rockfall hazard and risk assessments are recognized as some of the most challenging surveys among the geoengineering society, due to the urgent need for accurate f...

Here we present a joint analysis of the geodetic, seismological and geological data of the March 2021 Northern Thessaly seismic sequence, that were gathered and processed as of April 30, 2021. First, we relocated seismicity data from regional and local networks and inferred the dip-direction (NE) and dip-angle (38°) of the March 3, 2021 rupture pla...

The island of Lefkada, Greece periodically suffered environmental and structural damages induced by earthquakes. During the twenty-first century, two moderate events of magnitude M > 6 occurred in 2003 and 2015 (M6.2 and M6.5, respectively). The dominant type of the earthquake-induced environmental failures was rock falls and slides that were wides...

On March 3, 2021 a Mw=6.3 shallow earthquake occurred in the mountainous region of Damasi, about 20 km to the northwest of Larisa, Thessaly, central Greece, in a region of active crustal extension but of low strain. This event was followed by a Mw=6.0 shallow earthquake on March 4, 2021 about 12 km to the northwest, inside the sedimentary basin of...

On the 3rd and 4th of March 2021, two strong earthquakes of M6.3 and M6.0, respectively occurred at Thessaly, Central Greece. During extensive field survey and mapping, accompanied by UAV aerial surveys, following the strong earthquakes, numerous (more than 400 cases) liquefaction-related features were identified, including sand blows and craters,...

The correlation of coseismic landslides with the seismic and morphological parameters has been investigated in detail by many researchers, mainly after the devastating 2008 M8.0 Wenchuan, China earthquake. One of the goals of such studies is to examine the spatial distribution of the earthquake-induced landslides in order to establish a pattern dep...

The triggering of slope failures can cause a significant impact on human settlements and infrastructure in cities, coasts, islands and mountains. Therefore, a reliable evaluation of the landslide hazard would help mitigate the effects of such landslides and decrease the relevant risk. The goal of this paper is to develop, for the first time on a re...

Landslides represent a significant hazard for pipelines because they can generate permanent ground displacement and tend to result in complete failure or significant leaks, major environmental impacts and long periods of service disruption. Hence, landslide-related incidents are regarded as a significant operational risk. The paper mainly focuses o...

On September 17-20 2020 Medicane Ianos impacted Greece. The Medicane was associated with significant wind speeds, and precipitation. The amount of precipitation during a duration of about ~48 hrs was among the highest recorded in certain areas and exceeded in certain areas the mean annual precipitation. The extent of the affected area was very larg...

Soil liquefaction in the free field usually results in the generation of sand craters and volcanoes, as well as in surface ground cracks due to subsidence and lateral displacements. Technical constructions built on or within liquefiable soils may exhibit liquefaction-induced structural damages due to differential settlements, displacements and/or t...

The scope of this project, named Landslide Risk Management of Attica Region (DIAS), is to construct a uniform and updated database of slope failures that have taken place in the Attica Region (Greece), and compile a landslide inventory map for the development of raster cartographic products (such as those of hazard and risk maps) capable of support...

Rockfall consists one of the most harmful geological phenomena for the man-made environment. In order to evaluate the rockfall hazard, a variety of engineering geological studies should be realized, starting from conducting a detailed field survey and ending with simulating the trajectory of likely to fail blocks in order to evaluate the kinetic en...

Rockfalls are one of the most dominant geological hazards in mountainous rocky regions with the potential to turn catastrophic if they occur in an anthropogenic environment. Therefore, the identification of potential rockfall locations is of high importance. Susceptibility is the magnitude that describes these locations and its qualitative and quan...

Seismically generated landslides represent one of the most damaging hazards associated with earthquakes in countries with high seismicity. The delineation of prone to coseismic landsliding areas is crucial in order to predict the occurrence of earthquake-induced landslides and consequently reduce the relevant risk. The goal of this study is to inve...

The earthquake Mw6.6 (macroseismic intensity VIII, ESI-07 scale) that occurred on July 20, 2017 at 22:31 UTC (01:31 local time) in Gökova Bay, SE Aegean Sea, induced minor damages to contemporary structures at the island of Kos, Greece, while severe damages were reported on Venetian and Ottoman-era constructions, causing two deaths. Focusing on the...

The strong M7.3 November 12 2017 earthquake at the border region of Iraq‐Iran activated a massive landslide near Mela Kabod village, Iran. The Mela Kabod landslide was the most significant secondary effect of the 2017 earthquake and of considerable importance, due to its size, for the study and documentation of earthquake environmental effects. Usi...

Remote sensing techniques have become increasingly popular within the engineering geological field with multiple applications, such as the detection, identification and evaluation of the structural features of rockmasses, stability analysis and assessment of slopes, underground excavations, mines, rockmass assessment, etc. Within this concept, LiDA...

Santorini Island constitutes one of most unique geological structures as it compromises a distinctive Miocene volcano. Rockfalls and landslides are widespread phenomena in Santorini due to orientation and steepness of the cliffs which are mainly formed as high elevated lava domes with loose material inside, extruded by sticky, slow-flowing dacite l...

On November 17, 2015 07:10 UTC an earthquake of Mw 6.5 induced slope failures mainly at the western part of the island of Lefkada, Ionian Sea, Greece. The most characteristic one is the Okeanos site deep-seated landslide (near village Athani) that affected the man-made environment; part of the site, including a dirt road, moved downwards along the...

Laser scanning has proven useful in the stability assessment of underground openings. High accuracy points captured are used to generate 3D surface models to evaluate their stability by assessing rockmass structural features. A series of scans obtained from underground ancient quarries in Paros Island were processed. The structural analysis of the...

A moderate, shallow depth, earthquake (Mw = 6.5) occurred onshore Lefkada island on November 17, 2015 with the focal depth estimated at 11 km. The seismic fault is a near-vertical strike-slip fault running along the western coast, part of the Cephalonia Transform Fault. Landslides and ground cracks were mainly reported at the western part of the is...

Documentation of earthquake environmental effects (surface ruptures, landslides etc.) is a very critical issue, since based on the accuracy of the provided information, protection and mitigation measures can be designed. UAVs provide a convenient remote sensing platform for post-earthquake surveys given their ability to collect ultra-high resolutio...

Macroseismic intensity scales are used in order to measure the size of an earthquake using the impact of the ground shaking on humans, man made environment and nature. The INQUA scale is a new scale based solely on the earthquake-induced ground deformations, proposed by the INQUA Subcommission on Paleoseismicity. This scale is applied to the Sofade...

The strong shallow earthquake earthquake Mw6.6 occurred on July 20, 2017 at 22:31 UTC (01:31 local time) in Gökova Bay offshore between Bodrum, Turkey and the island of Kos, Greece, Aegean Sea. The secondary effects were documented during a field survey conducted on 13-14 August, 2017. Liquefaction-induced failures were reported at cape Louros and...

A chain fault reactivation took place in central Apennines, from August 24 to October 30, 2016, producing five moderate-to-strong earthquakes ranging from Mw5.5 to Mw6.6. This paper presents the results from the study of the ground co-seismic ruptures around the Monte Vettore and Vettoretto, and Norcia. Surface co-seismic ruptures, were observed in...

The subject of this work is the investigation of the interaction between groundwater and seismic waves, resulting in liquefaction of the soil, a particularly dangerous phenomenon. Therefore, estimates of liquefaction potential can significantly contribute to the prevention of such effects and consequently to reduction of the seismic risk. The study...

The outstanding Red Beach in Santorini, a famous volcanic island in the Aegean Sea in the territory of Greece, exhibits extended rockfall instabilities along its cliffs, placing its highly frequented touristic zones at high risk. This study aimed to generate an engineering geological interpretation of these instabilities and to evaluate the degree...

The 17th November Mw=6.4 shallow event occurred along a N20±5°E strike-slip fault with right-lateral sense of slip. The earthquake caused a lot of structural damage to the villages of Agios Petros, Athani, Dragano and Komilio, all located in south Lefkada island. Environmental effects include liquefaction, extensive rock falls and landslides. No su...

The scope of this study is to investigate the failure mechanisms of the eastern coastal zone of Mount Athos, using the LiDar device for the 3D mapping of the structural features of the rock mass. Therefore emphasis was given to the study of the planes of discontinuities that can trigger potential failures. All slopes were scanned by LiDar device in...

Η παρούσα έρευνα εστιάζεται στην χρήση επίγειου σαρωτή LiDar στην τεχνικογεωλογική ερμηνεία του φαινομένου των καταπτώσεων και στην αξιολόγηση του βαθμού επικινδυνότητας εκδήλωσης νέων καταπτώσεων σε ηφαιστειακό πρανές της νήσου Σαντορίνης. Στην περιοχή εκτός από την επίγεια σάρωση, εφαρμόστηκαν τοπογραφικές μέθοδοι για την ειδική αποτύπωση των βρα...

Landslides represent a significant hazard for pipelines because they can generate permanent ground displacement and tend to result in complete failure or significant leaks, major environmental impacts and long periods of service disruption. Hence, landslide-related incidents are regarded as a significant operational risk. The paper mainly focuses o...

The Mw 7.8 earthquake on 13th November 2016 was the largest earthquake onshore in New Zealand since the 1855 Wairarapa event. The event consisted of a complex rupture pattern involving multiple different fault and fault segments totaling over 200 km of length. The earthquake had only minimal casualties and damages to settlements due to the area aff...

Two radar images were acquired by the Sentinel-1 satellite on June 4, 2017 (S1B), and June 10, 2017 (S1A) before and shortly after the Amyntaio (Anargyroi) landslide in western Macedonia (Greece) on June 10, 2017. S1 images are both ascending passes from track 102 and their spatial resolution is 10 metres. The processed images clearly show the land...

On December 17, 2009, a large size rock fall generated at the area of Tempi, Central Greece causing one casualty. In particular, a large block was detached from a high of 70 meters and started to roll downslope and gradually became a rock slide. About 120 tones of rock material moved downward to the road resulting to the close of the national road....

The basic goal of this study is the delineation of liquefaction susceptibility zones by correlating geological, geomorphological, seismological and past liquefaction occurrences information. A liquefaction susceptibility map should be used as a screening guide by decision makers for avoiding in advance prone to liquefaction areas. In order to compi...

An issue that should be taken into account by urban planners in Greece, for the extension of urban areas, is the likelihood of earthquake-induced ground deformations. In this paper, information is provided regarding the methodology that is applied for the prediction of liquefaction manifestations in urban environment. In particular, a review of our...

On November 17, 2015 a strong, shallow earthquake (Mw = 6.5) occurred on the island of Lefkada along a N20 ± 5°E, east-dipping strike-slip fault with right-lateral sense of slip. The event triggered environmental effects that were mainly mapped at the western part of the island while moving towards the eastern part, the severity of the earthquake-i...

15ης Οκτωβρίου 2016, Μw=5.3, στην ευρύτερη περιοχή Ιωαννίνων, τίθεται το πρό-βλημα της επανεξέτασης της γεωλογικής δομής της ευρύτερης περιοχής με νεότερες σύγχρονες μεθό-δους και τεχνικές, σε σχέση με την γεωλογική-σεισμολογική ιδιομορφία της πρόσφατης σεισμικής ακο-λουθίας. Επίσης εξετάζεται η σεισμική διέγερση κατολισθήσεων και άλλων εδαφικών πα...

Norcia και La Piana di Castelluccio, σε υψόμετρο ~ 1400 m, στο βουνό Monte Vettore (υψομ. 2476m) και Vettoretto με τα τρία χαρτογραφημένα ρήγματα ΒΒΔ-ΝΝΑ διεύθυνσης. Οι επιφανειακές συν-σεισμικές διαρρήξεις, στο τμήμα του ρήγματος (segment) Vettore και Vettoretto εμφανίζονται για ορισμένα χιλιόμετρα (~ 7 km) στους σεισμούς του Αυγούστου σε μεγάλα υ...

With the release of new Sentinel-2 images, and other available resources for the M7.8 Kaikoura earthquake, we present an update of the Map of Co-Seismic Landslides and Surfaces Ruptures (As of 27/11/2016). Landslides were mapped using Sentinel-2 satellite images from Copernicus, European Space Agency, dated 15,22 and 25 November 2016. Images were...

Landslides were mapped using Sentinel-2 satellite images from Copernicus, European Space Agency, dated 15 November 2016. Images were compared with previous last available image without cloud cover (13 September and 26 October). Areas covered by cloud are omitted and shown on map. 1092 landslide sites are shown. Due to the preliminary nature of the...

On January 26th and February 3rd, 2014, two earthquakes occurred onshore the island of Cephalonia inducing severe environmental effects. The main types of earthquake-induced failures were liquefaction and slope failures and were mainly widespread at the western and central part of the island at Paliki peninsula. Although the fact that the generated...