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Papers by Joanna Papoulia
Social Science Research Network, 2022
Tectonophysics, 1978
Deep seismic soundings performed in Greece in the years 19711974 revealed that the area of Greec... more Deep seismic soundings performed in Greece in the years 19711974 revealed that the area of Greece consists of continental crust of variable thickness. The crust of the west Hellenic chains is 46 km thick and covered by sediments which locally exceed 10 km. That of the Aegean ...
Active Volcanoes of the World, 2017
A Vp velocity model of the sediments, crust and upper mantle of the Kos-Rhodos area, southeastern... more A Vp velocity model of the sediments, crust and upper mantle of the Kos-Rhodos area, southeastern Aegean Sea, was obtained by evaluating wide aperture reflection refraction seismic data, collected by using 4C Ocean Bottom Seismographs (OBS) and stand-alone land stations along 8 seismic lines of 1000 km total length. Seismic energy was generated by air gun shots spaced at 120 m intervals fired by a tuned air gun array of 49 l volume. Velocity modelling by seismic tomography and ray tracing revealed the structure of the crust and sediments. Good Ps, Pg and PmP reflections were recorded at nearly all observed sections, allowing delineating the sediments and crust structure and defining crustal thickness. The sediments are 3–5 km thick. Four sedimentary layers were mapped with velocities ranging from 1.7 to 5.4 km/s. The lateral velocity variations in the sediments and the existence of several faults indicate intense fragmentation and the development of several individual basins, like the western and eastern Kos basins, the Kondelioussa basin, the north Karpathos basin, the south Nisyros basin, the Tilos basin and a number of basins west of Rhodos. The upper crust is approx. 6.5 km thick with Vp velocities ranging from 5.8 to 6.5 km/s. The lower crust is 10–12 km thick with Vp velocities 6.8–7.2 km/s. The crust is stretched continental, with the Moho discontinuity located at 17 km towards the Cretan Sea, 20 km below Kos—Nisyros area, thickening to 22 km under Rhodos and western Turkey. Pn velocities have a value of approx. 7.8 km/s, indicating that below the Dodecanese area a low velocity zone exists in the uppermost part of the mantle, limited in depth by a high velocity layer of approx. 8.1 km/s. A deep sub-Moho reflector at 31 km depth was identified, implying the solid nature of rocks in the upper mantle. Magmatic intrusions were identified in the broader Caldera region.
SEG Technical Program Expanded Abstracts 2018, 2018
Seismic Instruments, 2012
The paper describes the structure and organization of operation of a portable telemetric seismo l... more The paper describes the structure and organization of operation of a portable telemetric seismo logical station, as well as its use for both terrestrial and marine observations. The main attention is paid to the implementation of the scheme of data transmission by a real time protocol, as well as to the feature of oper ation by this protocol while using a cellular communication channel. Using a standard protocol and a cellular network, in conjunction with low power consumption, relatively small cost of equipment, and ease of instal lation and maintenance make our solution attractive for the rapid deployment of a network of such stations. This is topical for regular monitoring of an object (or a region) to assess seismic hazards, tsunami warning, as well as in areas of aftershock activity following large earthquakes. Through the use of standard real time pro tocols, data is transmitted to data processing centers and do not require additional configuration of mathe matical support and an expensive procedure to organize processing of new data streams.
Journal of Applied Geophysics, 2007
Shallow seismic surveys can constitute a useful tool in actively deforming regions by yielding pr... more Shallow seismic surveys can constitute a useful tool in actively deforming regions by yielding precise information on the location of active faults, their geometry and cumulative displacement. Since the structures in these regions are rarely flat but always with sharp dips, 3D effects and side reflections can influence the results, thus the interpretation must be combined with geomorphological and geological data. The application of shallow seismic techniques in the hanging wall area of the Atalanti normal fault, central Greece, provided new data on hanging wall deformation, the amount of crustal extension and the long-term slip distribution along the fault.
Active Volcanoes of the World, 2017
Geophysical Journal International, 2013
In order to assess geological and environmental hazard in the south Evoikos basin, between Gramma... more In order to assess geological and environmental hazard in the south Evoikos basin, between Grammatiko and Aliveri, we performed a combined geophysical, sentimentological and oceanographic study. The geophysical results obtained from velocity modeling from 38 ocean bottom seismographs, single channel high resolution seismics, microseismicity observations from local amphibious arrays and magnetic mapping revealed the following results: The Basin is 1900m thick at the SSW, and 1500m thick at the NNE part of it, and is developed in two phases. Extension opened first an 8 Km wide basin at its SSW part, causing 180m subsidence, adding another 220m of sediments during a second phase of stretching that caused the complete basin to subside, and is still active. These recent sedimentary layers overlie a 3.2Km/s sequence with inclusions of highly magnetized rocks transported during the last glaciation period from Evia to the SSW. The lower part of the Basin is floored by two layers of 4.25 and...
72nd EAGE Conference and Exhibition incorporating SPE EUROPEC 2010, 2010
New findings about the deep origin of the geothermal fields and volcanic centres of the North Evi... more New findings about the deep origin of the geothermal fields and volcanic centres of the North Evian Gulf area, Central Greece, were arisen by combining a three-dimensional traveltime inversion study of a microseismic dataset recorded of 37 portable stations together with a Curie depth point analysis based on aeromagnetic data. A possible magma chamber can be presumed by the detection of a low seismic velocity volume with high Poisson ratio values at depths below 8 km and the Curie point depth estimation at about 7-8 km depth as well.
In Fall 2006, we deployed a combined on/offshore seismic network consisting of 17 4C ocean bottom... more In Fall 2006, we deployed a combined on/offshore seismic network consisting of 17 4C ocean bottom seismographs and 15 3C land-stations in the Kyparissiakos gulf and the surrounding area, of western Peleponese and observed the seismic activity for a period of 2 months. We located more than 3,500 earthquakes by using arrivals from a minimum of 6 stations at a time, applying a local velocity model obtained from active seismic observations. For 581 earthquakes we also defined local mechanisms. Seismic activity is closely associated with the active fault zones of this area: The shallow seismicity (0 to 15 km ) is mainly confined at the continent-ocean crustal transition approximately 70 km west of the island of Zakynthos, onshore Zakynthos and the area of Pylos, western part of Messinia (SW-Peleponese). All three zones are deforming by thrusting of the westwards moving Hellenic napes, which form topographic uplifts and are frequently associated with exposed metamorphic limestones. The orientation of this fault system is parallel to the collision front. Seismicity associated with the deeper part of the crust (15 -30 Km) coincides with the tectonically uplifted blocks of Messinia and that of the island of Zakynthos.
Bollettino di Geofisica Teorica ed Applicata
The volcanic edifice of Thera is located at the transition between the thickened crust of the Cyc... more The volcanic edifice of Thera is located at the transition between the thickened crust of the Cyclades massif, to the north, and the stretched continental crust of the Cretan sea, to the south. In the Cyclades area, crustal thickness is approximately 25 Km, whereas in the Cretan Sea, the crust is 15 to 18 Km thick. The in-between zone limits two different crustal units and at the same time two different tectonic regimes: the Cyclades that have developed by compression and thrusting, and the Cretan Sea dominating by transtension and crustal thinning. Volcanic activity, expressed by the volcanoes of Santorini, Colombo and Milos, occurs along this zone. Magma, originating from a depth of approximately 120 Km, finds its way to the surface through zones of weakness at the limit of the two crustal domains.
Social Science Research Network, 2022
Tectonophysics, 1978
Deep seismic soundings performed in Greece in the years 19711974 revealed that the area of Greec... more Deep seismic soundings performed in Greece in the years 19711974 revealed that the area of Greece consists of continental crust of variable thickness. The crust of the west Hellenic chains is 46 km thick and covered by sediments which locally exceed 10 km. That of the Aegean ...
Active Volcanoes of the World, 2017
A Vp velocity model of the sediments, crust and upper mantle of the Kos-Rhodos area, southeastern... more A Vp velocity model of the sediments, crust and upper mantle of the Kos-Rhodos area, southeastern Aegean Sea, was obtained by evaluating wide aperture reflection refraction seismic data, collected by using 4C Ocean Bottom Seismographs (OBS) and stand-alone land stations along 8 seismic lines of 1000 km total length. Seismic energy was generated by air gun shots spaced at 120 m intervals fired by a tuned air gun array of 49 l volume. Velocity modelling by seismic tomography and ray tracing revealed the structure of the crust and sediments. Good Ps, Pg and PmP reflections were recorded at nearly all observed sections, allowing delineating the sediments and crust structure and defining crustal thickness. The sediments are 3–5 km thick. Four sedimentary layers were mapped with velocities ranging from 1.7 to 5.4 km/s. The lateral velocity variations in the sediments and the existence of several faults indicate intense fragmentation and the development of several individual basins, like the western and eastern Kos basins, the Kondelioussa basin, the north Karpathos basin, the south Nisyros basin, the Tilos basin and a number of basins west of Rhodos. The upper crust is approx. 6.5 km thick with Vp velocities ranging from 5.8 to 6.5 km/s. The lower crust is 10–12 km thick with Vp velocities 6.8–7.2 km/s. The crust is stretched continental, with the Moho discontinuity located at 17 km towards the Cretan Sea, 20 km below Kos—Nisyros area, thickening to 22 km under Rhodos and western Turkey. Pn velocities have a value of approx. 7.8 km/s, indicating that below the Dodecanese area a low velocity zone exists in the uppermost part of the mantle, limited in depth by a high velocity layer of approx. 8.1 km/s. A deep sub-Moho reflector at 31 km depth was identified, implying the solid nature of rocks in the upper mantle. Magmatic intrusions were identified in the broader Caldera region.
SEG Technical Program Expanded Abstracts 2018, 2018
Seismic Instruments, 2012
The paper describes the structure and organization of operation of a portable telemetric seismo l... more The paper describes the structure and organization of operation of a portable telemetric seismo logical station, as well as its use for both terrestrial and marine observations. The main attention is paid to the implementation of the scheme of data transmission by a real time protocol, as well as to the feature of oper ation by this protocol while using a cellular communication channel. Using a standard protocol and a cellular network, in conjunction with low power consumption, relatively small cost of equipment, and ease of instal lation and maintenance make our solution attractive for the rapid deployment of a network of such stations. This is topical for regular monitoring of an object (or a region) to assess seismic hazards, tsunami warning, as well as in areas of aftershock activity following large earthquakes. Through the use of standard real time pro tocols, data is transmitted to data processing centers and do not require additional configuration of mathe matical support and an expensive procedure to organize processing of new data streams.
Journal of Applied Geophysics, 2007
Shallow seismic surveys can constitute a useful tool in actively deforming regions by yielding pr... more Shallow seismic surveys can constitute a useful tool in actively deforming regions by yielding precise information on the location of active faults, their geometry and cumulative displacement. Since the structures in these regions are rarely flat but always with sharp dips, 3D effects and side reflections can influence the results, thus the interpretation must be combined with geomorphological and geological data. The application of shallow seismic techniques in the hanging wall area of the Atalanti normal fault, central Greece, provided new data on hanging wall deformation, the amount of crustal extension and the long-term slip distribution along the fault.
Active Volcanoes of the World, 2017
Geophysical Journal International, 2013
In order to assess geological and environmental hazard in the south Evoikos basin, between Gramma... more In order to assess geological and environmental hazard in the south Evoikos basin, between Grammatiko and Aliveri, we performed a combined geophysical, sentimentological and oceanographic study. The geophysical results obtained from velocity modeling from 38 ocean bottom seismographs, single channel high resolution seismics, microseismicity observations from local amphibious arrays and magnetic mapping revealed the following results: The Basin is 1900m thick at the SSW, and 1500m thick at the NNE part of it, and is developed in two phases. Extension opened first an 8 Km wide basin at its SSW part, causing 180m subsidence, adding another 220m of sediments during a second phase of stretching that caused the complete basin to subside, and is still active. These recent sedimentary layers overlie a 3.2Km/s sequence with inclusions of highly magnetized rocks transported during the last glaciation period from Evia to the SSW. The lower part of the Basin is floored by two layers of 4.25 and...
72nd EAGE Conference and Exhibition incorporating SPE EUROPEC 2010, 2010
New findings about the deep origin of the geothermal fields and volcanic centres of the North Evi... more New findings about the deep origin of the geothermal fields and volcanic centres of the North Evian Gulf area, Central Greece, were arisen by combining a three-dimensional traveltime inversion study of a microseismic dataset recorded of 37 portable stations together with a Curie depth point analysis based on aeromagnetic data. A possible magma chamber can be presumed by the detection of a low seismic velocity volume with high Poisson ratio values at depths below 8 km and the Curie point depth estimation at about 7-8 km depth as well.
In Fall 2006, we deployed a combined on/offshore seismic network consisting of 17 4C ocean bottom... more In Fall 2006, we deployed a combined on/offshore seismic network consisting of 17 4C ocean bottom seismographs and 15 3C land-stations in the Kyparissiakos gulf and the surrounding area, of western Peleponese and observed the seismic activity for a period of 2 months. We located more than 3,500 earthquakes by using arrivals from a minimum of 6 stations at a time, applying a local velocity model obtained from active seismic observations. For 581 earthquakes we also defined local mechanisms. Seismic activity is closely associated with the active fault zones of this area: The shallow seismicity (0 to 15 km ) is mainly confined at the continent-ocean crustal transition approximately 70 km west of the island of Zakynthos, onshore Zakynthos and the area of Pylos, western part of Messinia (SW-Peleponese). All three zones are deforming by thrusting of the westwards moving Hellenic napes, which form topographic uplifts and are frequently associated with exposed metamorphic limestones. The orientation of this fault system is parallel to the collision front. Seismicity associated with the deeper part of the crust (15 -30 Km) coincides with the tectonically uplifted blocks of Messinia and that of the island of Zakynthos.
Bollettino di Geofisica Teorica ed Applicata
The volcanic edifice of Thera is located at the transition between the thickened crust of the Cyc... more The volcanic edifice of Thera is located at the transition between the thickened crust of the Cyclades massif, to the north, and the stretched continental crust of the Cretan sea, to the south. In the Cyclades area, crustal thickness is approximately 25 Km, whereas in the Cretan Sea, the crust is 15 to 18 Km thick. The in-between zone limits two different crustal units and at the same time two different tectonic regimes: the Cyclades that have developed by compression and thrusting, and the Cretan Sea dominating by transtension and crustal thinning. Volcanic activity, expressed by the volcanoes of Santorini, Colombo and Milos, occurs along this zone. Magma, originating from a depth of approximately 120 Km, finds its way to the surface through zones of weakness at the limit of the two crustal domains.