Ioannis Koukouvelas | University of Patras (original) (raw)

Papers by Ioannis Koukouvelas

European Journal of Geography, 2021

A riverbed swamp in the Krathis River, N. Peloponnese, is studied and analyzed geomorphologicaly.... more A riverbed swamp in the Krathis River, N. Peloponnese, is studied and analyzed geomorphologicaly. Our analysis is also based on sedimentological, geochemical, palaeontological and radiometric dating data which enabled the investigation of the possible relationship between the studied swamp and the 1913 Tsivlos landslide. Sedimentological analysis showed that the current sedimentation is dominated by fine grain material and occasional coarse-grained beds. Micropalaeontological analysis indicated that the deeper layers of the core are barren, while the upper ones contain fresh water ostracods suggesting hydrodynamically a progressively more stable environment. In accordance, radiocarbon C14 and 137Cs dating showed a progressively decreasing sedimentation rate over the last fifty years. The results of this study show that the Tsivlos landslide is not the only cause for the formation of the modern swamp. Tectonic movements in the area seem to play a decisive role causing uplift and subs...

Journal of Structural Geology, 2007

New finite strain data from a thrust-sense shear zone, which extends for 600km along-strike in th... more New finite strain data from a thrust-sense shear zone, which extends for 600km along-strike in the high-pressure belt of the External Hellenides (Greece), were used to describe the variation of ductile strain with structural distance (D) from the basal thrust. Sampling was carried out along four traverses across the central and southeastern parts of the zone. The strain ratio in XZ sections (RXZ) of 120 samples was obtained using the theta-curve, the mean object ellipse and the mean radial length methods. All methods give very consistent ...

Journal of Structural Geology, 2013

This study investigates the tectonic evolution of the Omalos transverse zone, which served as a c... more This study investigates the tectonic evolution of the Omalos transverse zone, which served as a crustal-scale oblique ramp in the External Hellenides thrust belt on Crete island. The Omalos oblique ramp developed above an inherited Mesozoic fault zone that strikes NE-SW, oblique to the regional SSW-directed tectonic transport. During the Early Miocene-Pleistocene evolution of the thrust belt, the oblique ramp was repeatedly reactivated localizing deformation above the inherited structure. Geological and structural mapping combined with kinematic analysis of ductile and brittle structures suggest that the Omalos oblique ramp generated a local kinematic field, which deviated significantly from the regional kinematic pattern in the thrust belt. The most conspicuous feature in the tectonic evolution of the oblique ramp is a change from a ductile wrench-dominated to a brittle, primarily reverse faulting regime across the brittle-ductile transition, followed by brittle wrench deformation after the final exhumation of high-pressure (HP) rocks. Deflections of transport and compression orientations from the regional pattern are attributed to buttressing against basement-cover offsets produced by the preexisting fault zone, to oblique ramping, and to transfer faulting, respectively. Our findings are potentially applicable to other examples of crustal-scale oblique thrust ramps in various tectonic settings.

Geological Journal, 2011

In the central Aegean, the Cycladic island of Amorgos consists of two high-pressure (HP) units, t... more In the central Aegean, the Cycladic island of Amorgos consists of two high-pressure (HP) units, the marble-rich Amorgos unit, which is correlated to the Mesozoic 'cover' sequence of the Menderes Massif, and the Cycladic Blueschist unit. New structural data show that the deformation history of the Amorgos HP-rocks was principally governed by early Oligocene (or late Eocene)-early Miocene ductile to brittle thrusting (D 1-D 3) followed by middle-late Miocene oblique contractional movements (D 4-D 5). The D 1 phase caused syn-blueschist-facies ductile thrusting of the Cycladic Blueschist unit over the Amorgos unit, with ambiguous kinematics. Progressive deformation under continuous NW-SE compression produced a sequence of imbricate NW-directed thrusts (D 2/3) characterized by a stratification of faultrelated rocks, with mylonitic zones (D 2) giving way downwards to cataclastic zones (D 3). Ductile D 2 thrusting synchronous to greenschistfacies retrogression, was accompanied by mega-sheath folding during constrictional and general shear deformation. Brittle D 3 thrusting was associated with NW-verging F 3 folds trending at a high-angle to the transport direction. Orthogonal contraction gave way to transpression during which the compression orientation changed from NW-SE (D 4) to NE-SW (D 5). Back-arc related NW-SE pure extension (D 6) seems to have been established in post-late Miocene times and related high-angle normal faulting affected HP-rocks only after they had already reached the uppermost crustal levels. Oligocene-early Miocene deformation history is interpreted to indicate syn-compressional exhumation of HP-rocks possibly in an extrusion wedge. In this case, Amorgos HP-rocks should have occupied the base of the extrusion wedge.

Comptes Rendus Geoscience, 2004

We performed palaeoseismological investigations along the Aigion Fault, one of the main faults th... more We performed palaeoseismological investigations along the Aigion Fault, one of the main faults that bound the southern side of the Corinth Gulf. The mapped trace of the Aigion Fault onland is about 8 km long and may extend as much as 14 km if one includes its offshore trace. We made detailed studies at two sites adjacent to the Meganitas River. Although dating of faulted sediments was a bit problematic, we present a preliminary estimate of the faults short-term slip rate and recurrence interval. Slip rates range from 1.6 to 4.3 mm yr −1 , with a maximum up to 6.3 mm yr −1. Three surface faulting events occurred in the seven centuries prior to 1888 AD, yielding an average (maximum) recurrence interval of 360 yr. To cite this article: D.

We document the active fold growth of the s outhern segment of the Ainos Thrust Fault (ATF), in t... more We document the active fold growth of the s outhern segment of the Ainos Thrust Fault (ATF), in the Cephalonia Island, Greece, based on tectonic geomorphic analysis using several indices of active tectonics along with geomorphic criteria. The Cephalonia Island is located at the external edge of the Hellenic fold-and-thrust system, one of the most active seismic regions worldwide, characterized by the frequent occurrence of large magnitude earthquakes. The approximately NW-SE-trending ATF is one of the most prominent tectonic features of the island. The southernmost ~20 km of the fault, which is the focus of this work, exhibits up to ~1600 m of topographic relief. Quantitative measurement of geomorphic indices such as the stream length-gradient index (SL), the mountain-front sinuosity (Smf), the valley floor width to valley height ratio (Vf) and the hypsometric integral (Hi), extracted from the DEM using standard GIS methods, were analyzed in order to identify the level of tectonic a...

Bulletin of the Geological Society of Greece, 2017

Remote Sensing and photogrammetric techniques have always been used in geological applications. C... more Remote Sensing and photogrammetric techniques have always been used in geological applications. Current advancements in the technology behind Unmanned Aerial Vehicles (UAVs), in accordance with the consecutive increase in affordability of such devices and the availability of photogrammetric software, makes their use for large or small scale land mapping more and more popular. With the UAVs being used for mapping, the problems of increased costs, time consumption and the possible accessibility problems -due to steep terrain-, are all solved at once. In this study, a custom-made UAV with 2 cameras onboard, is used to monitor two complex –regarding their topography- regions in Western Greece. One open pit limestone mine and a landslide occurring on sandy-clayous sediments. Both regions were mapped using surveying instruments like tachymeters and geodetic GPS, as well as using the aforementioned UAV system. 3D models of both regions were created using off-the-shelf photogrammetric softw...

Bulletin of the Geological Society of Greece, 2001

Paleoseismological analysis based on geological data enable us to understand the recent seismic h... more Paleoseismological analysis based on geological data enable us to understand the recent seismic history of the Eliki fault. Along the eastern "segment (or strand)" scarp 5 trenches have been excavated (8x5x2m), their walls were mapped in scale 1:20 and further analyzed by precise tectono-stratigraphic methodology. The Kerynitis river, which crosses the Eliki fault from S to Ν and supplies the alluvial plain, has subsided at a rate of 1.4 mm/ yr. The river was running from west to east, resulting the fluvial conglomerates in the trenches, which have buried under the colluvial sediments. Based on colluvium stratigraphy, displacement of distinct horizons, deposition of sedimentary layers and C14 dating, faulting events have been identified affecting unconsolidated sediments in the trench. The penultimate 373 BC event and the two younger events with a throw of 0.93 m and 1.37 m respectively, the third event, with a throw of 0.44 m, suggest a variable seismic history.

Bulletin of the Geological Society of Greece, 2004

Most active processes on the surface imply that tectonics and geomorphology converge in a way tha... more Most active processes on the surface imply that tectonics and geomorphology converge in a way that landscape change may be used as a tectonic signal, given that erosion and weathering have been taken into account. We selected two faults, the Kompotades and the Nea Anchialos faults in the Sperchios and South Thessaly rift zones respectively, and we performed a morphometric analysis. This analysis comprises geomorphic indices that have been used successfully in studies of active tectonics, as the mountain front sinuosity index (Smf), stream gradient index (SL) and valley floor width to valley height ratio (Vf). At both studied mountain fronts, the Vf index ranged between 0,4 to 1,2, implying high uplift rates, while the Smf «1 index revealed relatively high tectonic activity, which decreases towards the west. On the other hand, the SL index though more sensitive to non-tectonic processes, (i.e. the rock resistance, stream length) is less indicative of tectonic activity. Based on the d...

Bulletin of the Geological Society of Greece, 2017

The present study assessed landslide events over a time span of fifty years in the prefecture of ... more The present study assessed landslide events over a time span of fifty years in the prefecture of Ioannina. Historical data analysis commonly provides valuable data for understanding distribution of landslides. The methodology included collection and analysis of articles about landslides events found in the local newspapers between 1960 and 2008, also in the national newspapers (1960-1967) and in the contemporary national newspapers (1995-2008). The time interval selected in this study is representative of the entire time period of systematic newspapers publication. During this time spam, eighty nine historical landslides were identified. Newspaper articles annotate the time and the location of the landslides as well as primarily the role of weather conditions in triggering the landslides. In addition, published articles provide information on the damages caused by the landslides. The study shows that these events occurred due to extremely high precipitation, snowstorms or prolonged ...

Minerals, 2022

Beachrocks are generally mapped on the coastline surface and/or in a low depth in the subtidal zo... more Beachrocks are generally mapped on the coastline surface and/or in a low depth in the subtidal zone in coastlines and are cemented chiefly by carbonate material. Their outcrops may vary from a tenth of meters to a tenth of kilometers in length. Along the Epirus coast, in Greece, beachrocks outcrops are laying on the coastline for more than ten kilometers. In the present work, we used Unmanned Aerial Vehicles (UAVs), in situ sampling, and the Geographical Information System (GIS) to map three beachrock areas with a length of 500 m to 600 m each. In synergy with extended mineralogical and petrographic analyses, we provide preliminary data about the geographical distribution and the mineralogical differences of these beachrocks. Furthermore, for the first time, we tried to investigate the correlation between the geotectonic setting of the broader area and the beachrock extent, shape, and petrographic parameters. The laboratory analyses proved that the beachrocks belong to a similar dep...

Bulletin of the Geological Society of Greece, 2017

Inventory of pre-earthquake and earthquake triggered landslides is used to provide insight of the... more Inventory of pre-earthquake and earthquake triggered landslides is used to provide insight of the tectonic forcing in the development of the rock slopes of the Skolis Mountain, in the North Peloponnese. For the purposes of inventory of landslides we analyzed © Google Earth photographs based on drawing polygons and paths in order to create ‘Keyhole Markup Language’ or KML files. © Google Earth photographs analysis and surface mapping indicate that the Skolis Mountain is affected by long- term climatically and tectonically controlled rock falls and minor rock slides. The rock falls show a progressive inflation in surface area from 2007 to 2009. The post-earthquake surface area of the rock falls increased three times. In addition, there was a series of rock falls descending Skoli’s slopes by free fall, bouncing, or rolling causing damages in the Santomerion village and blocking significant part of the dirt roads around it. These boulders are clustered in three areas across the western ...

Comptes Rendus …, 2004

We performed palaeoseismological investigations along the Aigion Fault, one of the main faults th... more We performed palaeoseismological investigations along the Aigion Fault, one of the main faults that bound the southern side of the Corinth Gulf. The mapped trace of the Aigion Fault onland is about 8 km long and may extend as much as 14 km if one includes its offshore trace. We made detailed studies at two sites adjacent to the Meganitas River. Although dating of faulted sediments was a bit problematic, we present a preliminary estimate of the faults short-term slip rate and recurrence interval. Slip rates range from 1.6 to 4.3 mm yr −1 , with a maximum up to 6.3 mm yr −1. Three surface faulting events occurred in the seven centuries prior to 1888 AD, yielding an average (maximum) recurrence interval of 360 yr. To cite this article: D.

Geological Society, London, Special Publications, 2010

Microstructural, petrofabric, strain and vorticity data from quartz-rich tectonites were used to ... more Microstructural, petrofabric, strain and vorticity data from quartz-rich tectonites were used to investigate the kinematics of rock flow in the Evia and Ochi ductile thrust zones, formed during exhumation of the high-pressure nappes of the Attico-Cycladic Massif. The Evia thrust zone defines the base of the Styra nappe while the Ochi thrust zone defines the contact between the Styra and the overlying Ochi nappe. A dominant top-to-the-ENE sense of shearing along both thrust zones is indicated by several shear sense criteria. ...

Results from palaeoseismological trenching for four active faults in Greece are presented. The ma... more Results from palaeoseismological trenching for four active faults in Greece are presented. The main target is to determine palaeoearthquake slip and slip associated with events hosted on four active faults: two of them located with the Gulf of Corinth southern part of the Greece (Kaparelli and Eliki) and two in the northern Greece within the Mygdonia and Aliakmon basins. All excavated trenches expose evidence of more than three events, thus enabling to estimate the recurrence interval (RI) of past events and the slip rate (SR) of the faults. Results for the four faults are Eliki fault: RI = 900-400 years, SR = 1.5 mm/a, Kaparelli fault: RI = 2300 years, SR = 0.3 mm/a, Mygdonia fault: RI = 900 years, SR = 0.26-0.7 mm/a, and Paleohori-Sarakina fault: RI = 30,000 (?) years, SR = 0.01-0.03 mm/a. The latter result is under question, because a different dating method was used. From all trenches the inferred earthquake magnitude is in the order of 6.5. On the other hand, both RI and SR range two orders of magnitude with faults located southerly and easterly showing shorter RI and larger SR in reference with the northwesternmost Greece. This palaeoseismological study helps us to propose a model for the behaviour of large seismogenic faults in the Aegean area in response to their geotectonic setting.

European Journal of Geography, 2021

A riverbed swamp in the Krathis River, N. Peloponnese, is studied and analyzed geomorphologicaly.... more A riverbed swamp in the Krathis River, N. Peloponnese, is studied and analyzed geomorphologicaly. Our analysis is also based on sedimentological, geochemical, palaeontological and radiometric dating data which enabled the investigation of the possible relationship between the studied swamp and the 1913 Tsivlos landslide. Sedimentological analysis showed that the current sedimentation is dominated by fine grain material and occasional coarse-grained beds. Micropalaeontological analysis indicated that the deeper layers of the core are barren, while the upper ones contain fresh water ostracods suggesting hydrodynamically a progressively more stable environment. In accordance, radiocarbon C14 and 137Cs dating showed a progressively decreasing sedimentation rate over the last fifty years. The results of this study show that the Tsivlos landslide is not the only cause for the formation of the modern swamp. Tectonic movements in the area seem to play a decisive role causing uplift and subs...

Journal of Structural Geology, 2007

New finite strain data from a thrust-sense shear zone, which extends for 600km along-strike in th... more New finite strain data from a thrust-sense shear zone, which extends for 600km along-strike in the high-pressure belt of the External Hellenides (Greece), were used to describe the variation of ductile strain with structural distance (D) from the basal thrust. Sampling was carried out along four traverses across the central and southeastern parts of the zone. The strain ratio in XZ sections (RXZ) of 120 samples was obtained using the theta-curve, the mean object ellipse and the mean radial length methods. All methods give very consistent ...

Journal of Structural Geology, 2013

This study investigates the tectonic evolution of the Omalos transverse zone, which served as a c... more This study investigates the tectonic evolution of the Omalos transverse zone, which served as a crustal-scale oblique ramp in the External Hellenides thrust belt on Crete island. The Omalos oblique ramp developed above an inherited Mesozoic fault zone that strikes NE-SW, oblique to the regional SSW-directed tectonic transport. During the Early Miocene-Pleistocene evolution of the thrust belt, the oblique ramp was repeatedly reactivated localizing deformation above the inherited structure. Geological and structural mapping combined with kinematic analysis of ductile and brittle structures suggest that the Omalos oblique ramp generated a local kinematic field, which deviated significantly from the regional kinematic pattern in the thrust belt. The most conspicuous feature in the tectonic evolution of the oblique ramp is a change from a ductile wrench-dominated to a brittle, primarily reverse faulting regime across the brittle-ductile transition, followed by brittle wrench deformation after the final exhumation of high-pressure (HP) rocks. Deflections of transport and compression orientations from the regional pattern are attributed to buttressing against basement-cover offsets produced by the preexisting fault zone, to oblique ramping, and to transfer faulting, respectively. Our findings are potentially applicable to other examples of crustal-scale oblique thrust ramps in various tectonic settings.

Geological Journal, 2011

In the central Aegean, the Cycladic island of Amorgos consists of two high-pressure (HP) units, t... more In the central Aegean, the Cycladic island of Amorgos consists of two high-pressure (HP) units, the marble-rich Amorgos unit, which is correlated to the Mesozoic 'cover' sequence of the Menderes Massif, and the Cycladic Blueschist unit. New structural data show that the deformation history of the Amorgos HP-rocks was principally governed by early Oligocene (or late Eocene)-early Miocene ductile to brittle thrusting (D 1-D 3) followed by middle-late Miocene oblique contractional movements (D 4-D 5). The D 1 phase caused syn-blueschist-facies ductile thrusting of the Cycladic Blueschist unit over the Amorgos unit, with ambiguous kinematics. Progressive deformation under continuous NW-SE compression produced a sequence of imbricate NW-directed thrusts (D 2/3) characterized by a stratification of faultrelated rocks, with mylonitic zones (D 2) giving way downwards to cataclastic zones (D 3). Ductile D 2 thrusting synchronous to greenschistfacies retrogression, was accompanied by mega-sheath folding during constrictional and general shear deformation. Brittle D 3 thrusting was associated with NW-verging F 3 folds trending at a high-angle to the transport direction. Orthogonal contraction gave way to transpression during which the compression orientation changed from NW-SE (D 4) to NE-SW (D 5). Back-arc related NW-SE pure extension (D 6) seems to have been established in post-late Miocene times and related high-angle normal faulting affected HP-rocks only after they had already reached the uppermost crustal levels. Oligocene-early Miocene deformation history is interpreted to indicate syn-compressional exhumation of HP-rocks possibly in an extrusion wedge. In this case, Amorgos HP-rocks should have occupied the base of the extrusion wedge.

Comptes Rendus Geoscience, 2004

We performed palaeoseismological investigations along the Aigion Fault, one of the main faults th... more We performed palaeoseismological investigations along the Aigion Fault, one of the main faults that bound the southern side of the Corinth Gulf. The mapped trace of the Aigion Fault onland is about 8 km long and may extend as much as 14 km if one includes its offshore trace. We made detailed studies at two sites adjacent to the Meganitas River. Although dating of faulted sediments was a bit problematic, we present a preliminary estimate of the faults short-term slip rate and recurrence interval. Slip rates range from 1.6 to 4.3 mm yr −1 , with a maximum up to 6.3 mm yr −1. Three surface faulting events occurred in the seven centuries prior to 1888 AD, yielding an average (maximum) recurrence interval of 360 yr. To cite this article: D.

We document the active fold growth of the s outhern segment of the Ainos Thrust Fault (ATF), in t... more We document the active fold growth of the s outhern segment of the Ainos Thrust Fault (ATF), in the Cephalonia Island, Greece, based on tectonic geomorphic analysis using several indices of active tectonics along with geomorphic criteria. The Cephalonia Island is located at the external edge of the Hellenic fold-and-thrust system, one of the most active seismic regions worldwide, characterized by the frequent occurrence of large magnitude earthquakes. The approximately NW-SE-trending ATF is one of the most prominent tectonic features of the island. The southernmost ~20 km of the fault, which is the focus of this work, exhibits up to ~1600 m of topographic relief. Quantitative measurement of geomorphic indices such as the stream length-gradient index (SL), the mountain-front sinuosity (Smf), the valley floor width to valley height ratio (Vf) and the hypsometric integral (Hi), extracted from the DEM using standard GIS methods, were analyzed in order to identify the level of tectonic a...

Bulletin of the Geological Society of Greece, 2017

Remote Sensing and photogrammetric techniques have always been used in geological applications. C... more Remote Sensing and photogrammetric techniques have always been used in geological applications. Current advancements in the technology behind Unmanned Aerial Vehicles (UAVs), in accordance with the consecutive increase in affordability of such devices and the availability of photogrammetric software, makes their use for large or small scale land mapping more and more popular. With the UAVs being used for mapping, the problems of increased costs, time consumption and the possible accessibility problems -due to steep terrain-, are all solved at once. In this study, a custom-made UAV with 2 cameras onboard, is used to monitor two complex –regarding their topography- regions in Western Greece. One open pit limestone mine and a landslide occurring on sandy-clayous sediments. Both regions were mapped using surveying instruments like tachymeters and geodetic GPS, as well as using the aforementioned UAV system. 3D models of both regions were created using off-the-shelf photogrammetric softw...

Bulletin of the Geological Society of Greece, 2001

Paleoseismological analysis based on geological data enable us to understand the recent seismic h... more Paleoseismological analysis based on geological data enable us to understand the recent seismic history of the Eliki fault. Along the eastern "segment (or strand)" scarp 5 trenches have been excavated (8x5x2m), their walls were mapped in scale 1:20 and further analyzed by precise tectono-stratigraphic methodology. The Kerynitis river, which crosses the Eliki fault from S to Ν and supplies the alluvial plain, has subsided at a rate of 1.4 mm/ yr. The river was running from west to east, resulting the fluvial conglomerates in the trenches, which have buried under the colluvial sediments. Based on colluvium stratigraphy, displacement of distinct horizons, deposition of sedimentary layers and C14 dating, faulting events have been identified affecting unconsolidated sediments in the trench. The penultimate 373 BC event and the two younger events with a throw of 0.93 m and 1.37 m respectively, the third event, with a throw of 0.44 m, suggest a variable seismic history.

Bulletin of the Geological Society of Greece, 2004

Most active processes on the surface imply that tectonics and geomorphology converge in a way tha... more Most active processes on the surface imply that tectonics and geomorphology converge in a way that landscape change may be used as a tectonic signal, given that erosion and weathering have been taken into account. We selected two faults, the Kompotades and the Nea Anchialos faults in the Sperchios and South Thessaly rift zones respectively, and we performed a morphometric analysis. This analysis comprises geomorphic indices that have been used successfully in studies of active tectonics, as the mountain front sinuosity index (Smf), stream gradient index (SL) and valley floor width to valley height ratio (Vf). At both studied mountain fronts, the Vf index ranged between 0,4 to 1,2, implying high uplift rates, while the Smf «1 index revealed relatively high tectonic activity, which decreases towards the west. On the other hand, the SL index though more sensitive to non-tectonic processes, (i.e. the rock resistance, stream length) is less indicative of tectonic activity. Based on the d...

Bulletin of the Geological Society of Greece, 2017

The present study assessed landslide events over a time span of fifty years in the prefecture of ... more The present study assessed landslide events over a time span of fifty years in the prefecture of Ioannina. Historical data analysis commonly provides valuable data for understanding distribution of landslides. The methodology included collection and analysis of articles about landslides events found in the local newspapers between 1960 and 2008, also in the national newspapers (1960-1967) and in the contemporary national newspapers (1995-2008). The time interval selected in this study is representative of the entire time period of systematic newspapers publication. During this time spam, eighty nine historical landslides were identified. Newspaper articles annotate the time and the location of the landslides as well as primarily the role of weather conditions in triggering the landslides. In addition, published articles provide information on the damages caused by the landslides. The study shows that these events occurred due to extremely high precipitation, snowstorms or prolonged ...

Minerals, 2022

Beachrocks are generally mapped on the coastline surface and/or in a low depth in the subtidal zo... more Beachrocks are generally mapped on the coastline surface and/or in a low depth in the subtidal zone in coastlines and are cemented chiefly by carbonate material. Their outcrops may vary from a tenth of meters to a tenth of kilometers in length. Along the Epirus coast, in Greece, beachrocks outcrops are laying on the coastline for more than ten kilometers. In the present work, we used Unmanned Aerial Vehicles (UAVs), in situ sampling, and the Geographical Information System (GIS) to map three beachrock areas with a length of 500 m to 600 m each. In synergy with extended mineralogical and petrographic analyses, we provide preliminary data about the geographical distribution and the mineralogical differences of these beachrocks. Furthermore, for the first time, we tried to investigate the correlation between the geotectonic setting of the broader area and the beachrock extent, shape, and petrographic parameters. The laboratory analyses proved that the beachrocks belong to a similar dep...

Bulletin of the Geological Society of Greece, 2017

Inventory of pre-earthquake and earthquake triggered landslides is used to provide insight of the... more Inventory of pre-earthquake and earthquake triggered landslides is used to provide insight of the tectonic forcing in the development of the rock slopes of the Skolis Mountain, in the North Peloponnese. For the purposes of inventory of landslides we analyzed © Google Earth photographs based on drawing polygons and paths in order to create ‘Keyhole Markup Language’ or KML files. © Google Earth photographs analysis and surface mapping indicate that the Skolis Mountain is affected by long- term climatically and tectonically controlled rock falls and minor rock slides. The rock falls show a progressive inflation in surface area from 2007 to 2009. The post-earthquake surface area of the rock falls increased three times. In addition, there was a series of rock falls descending Skoli’s slopes by free fall, bouncing, or rolling causing damages in the Santomerion village and blocking significant part of the dirt roads around it. These boulders are clustered in three areas across the western ...

Comptes Rendus …, 2004

We performed palaeoseismological investigations along the Aigion Fault, one of the main faults th... more We performed palaeoseismological investigations along the Aigion Fault, one of the main faults that bound the southern side of the Corinth Gulf. The mapped trace of the Aigion Fault onland is about 8 km long and may extend as much as 14 km if one includes its offshore trace. We made detailed studies at two sites adjacent to the Meganitas River. Although dating of faulted sediments was a bit problematic, we present a preliminary estimate of the faults short-term slip rate and recurrence interval. Slip rates range from 1.6 to 4.3 mm yr −1 , with a maximum up to 6.3 mm yr −1. Three surface faulting events occurred in the seven centuries prior to 1888 AD, yielding an average (maximum) recurrence interval of 360 yr. To cite this article: D.

Geological Society, London, Special Publications, 2010

Microstructural, petrofabric, strain and vorticity data from quartz-rich tectonites were used to ... more Microstructural, petrofabric, strain and vorticity data from quartz-rich tectonites were used to investigate the kinematics of rock flow in the Evia and Ochi ductile thrust zones, formed during exhumation of the high-pressure nappes of the Attico-Cycladic Massif. The Evia thrust zone defines the base of the Styra nappe while the Ochi thrust zone defines the contact between the Styra and the overlying Ochi nappe. A dominant top-to-the-ENE sense of shearing along both thrust zones is indicated by several shear sense criteria. ...

Results from palaeoseismological trenching for four active faults in Greece are presented. The ma... more Results from palaeoseismological trenching for four active faults in Greece are presented. The main target is to determine palaeoearthquake slip and slip associated with events hosted on four active faults: two of them located with the Gulf of Corinth southern part of the Greece (Kaparelli and Eliki) and two in the northern Greece within the Mygdonia and Aliakmon basins. All excavated trenches expose evidence of more than three events, thus enabling to estimate the recurrence interval (RI) of past events and the slip rate (SR) of the faults. Results for the four faults are Eliki fault: RI = 900-400 years, SR = 1.5 mm/a, Kaparelli fault: RI = 2300 years, SR = 0.3 mm/a, Mygdonia fault: RI = 900 years, SR = 0.26-0.7 mm/a, and Paleohori-Sarakina fault: RI = 30,000 (?) years, SR = 0.01-0.03 mm/a. The latter result is under question, because a different dating method was used. From all trenches the inferred earthquake magnitude is in the order of 6.5. On the other hand, both RI and SR range two orders of magnitude with faults located southerly and easterly showing shorter RI and larger SR in reference with the northwesternmost Greece. This palaeoseismological study helps us to propose a model for the behaviour of large seismogenic faults in the Aegean area in response to their geotectonic setting.

Περίληψη Γεωτεκτονική τοποθέτηση: Το ρήγμα του Πηδήματος βρίσκεται στη Μεσσηνία (ΝΔ Πελοπόννησος)... more Περίληψη Γεωτεκτονική τοποθέτηση: Το ρήγμα του Πηδήματος βρίσκεται στη Μεσσηνία (ΝΔ Πελοπόννησος). Είναι μέρος της ρηξιγενούς ζώνης Ανατολικής Μεσσηνίας και το ίχνος του βρίσκεται στους δυτικούς πρόποδες του Ταϋγέτου, στη γειτονία των οικισμών Πήδημα και Αρφαρά. Το υπόβαθρο της λεκάνης της Καλαμάτας στη Μεσσηνία αποτελείται από αλπικά πετρώματα των Ζωνών Γαβρόβου-Τρίπολης και Ωλονού-Πίνδου. Το κεντρικό μέρος της λεκάνης καλύπτεται από μεταλπικά Πλειοκαινικά και Τεταρτογενή ιζήματα, τα οποία επικάθονται ασύμφωνα στο υπόβαθρο. Η νεοτεκτονική δομή της περιοχής χαρακτηρίζεται από την ύπαρξη τεκτονικών λεκανών και κεράτων λόγω της δράσης ρηγμάτων ΒΒΔ-ΝΝΑ διεύθυνσης. Δεδομένα: Η έρευνα επί της κατοπτρικής επιφάνειας του ρήγματος του Πηδήματος πραγματοποιήθηκε το Μάιο του 2015, με τη χρήση του επίγειου σαρωτή LIDAR ILRIS-(3D-HD). Η θέση σάρωσης βρισκόταν σε κάθετη απόσταση 10 m από την επιφάνεια και ο σαρωτής ρυθμίστηκε κατάλληλα ώστε το βήμα (χω-ρική ανάλυση) σάρωσης να είναι 1 mm. Σαρώθηκε όλη η αποκαλυμμένη ρηξιγενής επιφάνεια, εκτός από το ανώτερο τμήμα του νοτίου άκρου της λόγω πρακτικών δυσκολιών. Επεξεργασία δεδομένων: ο σκοπός της παρούσας εργασίας είναι η ανάλυση των αλλαγών της γωνίας και της διεύθυνσης κλίσης στην κατοπτρική επιφάνεια, χρησιμοποιώντας συνδυασμό αναλυτικών υπολογι-στικών εργαλείων. Συγκεκριμένα, χρησιμοποιήθηκε το πρόσθετο FACETS του λογισμικού ανοικτού κώ-δικα CloudCompare σε συνδυασμό με το ArcMap™. Καραμήτρος Ι., και συν.: Αποτύπωση και ανάλυση των γεωμετρικών χαρακτηριστικών της κατοπτρικής επιφά-νειας του ρήγματος στο Πήδημα Μεσσηνίας με τη χρήση επίγειου σαρωτή LIDAR. Εικόνα 1. Χάρτης της ΝΔ Πελοποννήσου με τη λεκάνη της Καλαμάτας. Το κόκκινο σημείο υποδεικνύει τη θέση με-λέτης στο ρήγμα του Πηδήματος.