Tectonic Processes and Crustal Evolution on/Offshore Western Peloponnese Derived From Active and Passive Seismics

Papoulia, J.; Makris, J.

doi:10.12681/bgsg.11187

Cited by 3 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This feature possibly corresponds to a low-angle shear zone representing the basal detachment accommodating the overlying Pelagonian nappe, mainly consisting of metamorphic rocks, onto the recrystallized carbonate platform of the Gavrovo unit. The result is corroborated by lithological succession in regions close to our study area (Makris et al, 2001;Papoulia and Makris, 2010;Makris and Papoulia, 2018) and in region characterized by similar geodynamic context, where a similar succession has been inferred (Improta et al, 2000;Amoroso et al, 2014;Napolitano et al, 2021). Currently, the latter extensively outcrops in the Mount Olympus tectonic window about Horizontal slices for 0-10 km depths showing P-and S-wave velocity models (left and right panels, respectively).…”

Section: Discussionsupporting

confidence: 88%

Seismic imaging of fluid-filled inherited structures of the Northern Thessaly (Greece) seismic gap

et al. 2023

View full text Add to dashboard Cite

We present the first seismic imaging of the crustal volume affected by the March-April 2021 Thessaly sequence by applying a 3D seismic tomography to the aftershocks recorded by an unprecedented number of stations. The results, in terms of VP, VS, and VP/VS ratio and earthquakes’ location parameters, depict blind fluid-filled inherited structures within the Northern Thessaly seismic gap. The tomographic images highlight the basal detachment accommodating the Pelagonian nappe onto the carbonate of the Gavrovo unit. The high VP/VS (>1.85) where most of the seismicity occurs increases from SE to NW, showing possible fluid accumulation in the NW edge of the seismogenic volume that could have contributed to the sequence evolution. The aftershock relocations correlate well with the fault planes of the three mainshocks proposed by several geodetic models, but also show additional possible faults sub-parallel and antithetical to the main structures, not to be overlooked for future seismic risk mitigation.

show abstract

Section: Discussionsupporting

confidence: 88%

Seismic imaging of fluid-filled inherited structures of the Northern Thessaly (Greece) seismic gap

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Varying fault plane dip angles could be attributed to listric thrust faults offshore Zakynthos (Kokinou et al 2005;Papoulia & Makris 2010;Kokkalas et al 2013). Cluster 3 was active immediately after the main shock (Fig.…”

Section: Discussion Part I: On the Methodological Implementationmentioning

confidence: 99%

Clusty, the waveform-based network similarity clustering toolbox: concept and application to image complex faulting offshore Zakynthos (Greece)

Petersen

Niemz

Cesca

et al. 2020

Geophysical Journal International

View full text Add to dashboard Cite

Summary Clusty is a new open source toolbox dedicated to earthquake clustering based on waveforms recorded across a network of seismic stations. Its main application is the study of active faults and the detection and characterization of faults and fault networks. By using a density-based clustering approach, earthquakes pertaining to a common fault can be recognised even over long fault segments, and the first-order geometry and extent of active faults can be inferred. Clusty implements multiple techniques to compute a waveform based network similarity from maximum cross-correlation coefficients at multiple stations. The clustering procedure is designed to be transparent and parameters can be easily tuned. It is supported by a number of analysis visualisation tools which help to assess the homogeneity within each cluster and the differences among distinct clusters. The toolbox returns graphical representations of the results. A list of representative events and stacked waveforms facilitate further analyses like moment tensor inversion. Results obtained in various frequency bands can be combined to account for large magnitude ranges. Thanks to the simple configuration, the toolbox is easily adaptable to new datasets and to large magnitude ranges. To show the potential of our new toolbox, we apply Clusty to the aftershock sequence of the Mw 6.9 October 25, 2018 Zakynthos (Greece) Earthquake. Thanks to the complex tectonic setting at the western termination of the Hellenic Subduction System where multiple faults and faulting styles operate simultaneously, the Zakynthos dataset provides an ideal case-study for our clustering analysis toolbox. Our results support the activation of several faults and provide insight into the geometry of faults or fault segments. We identify two large thrust faulting clusters in the vicinity of the mainshock and multiple strike-slip clusters to the east, west and south of these clusters. Despite its location within the largest thrust cluster, the mainshock does not show a high waveform similarity to any of the clusters. This is consistent with the results of other studies suggesting a complex failure mechanism for the mainshock. We propose the existence of conjugated strike-slip faults in the south of the study area. Our waveform similarity based clustering toolbox is able to reveal distinct event clusters which cannot be discriminated based on locations and/or timing only. Additionally, the clustering results allows distinction between fault and auxiliary planes of focal mechanisms and to associate them to known active faults.

show abstract

“…The tectonic map is compiled from numerous sources for Albania (Bega & Soto, 2017;Frashëri et al, 1996;Kilias et al, 2001;Meço et al, 2000;Robertson & Shallo, 2000;Scrocca et al, 2022;Velaj et al, 1999;Xhomo et al, 2002;Zelilidis et al, 2003Zelilidis et al, , 2015, Greece (Bornovas & Rondogianni-Tsiambaou, 1983;Bourli et al, 2019;Karakitsios & Rigakis, 2007;Kilias et al, 2002Kilias et al, , 2016Maravelis et al, 2014;Plougarlis et al, 2021;Zelilidis et al, 2003, 2015), Croatia, Kosovo, Montenegro, and North Macedonia (Schmid et al, 2020Schmitz et al, 2020). The geology in the offshore area integrates observations from Greece (Chamot-Rooke et al, 2005;Kokinou et al, 2005Kokinou et al, , 2006Monopolis & Bruneton, 1982;Papoulia & Makris, 2010;Sakellariou et al, 2013;Zelilidis et al, 2015Zelilidis et al, , 2016, Italy (Argnani et al, 2009;Auroux et al, 1985;Charier et al, 1988;de Alteriis, 1995;Fantoni & Franciosi, 2010;Festa et al, 2014;Santantonio et al, 2013), Albania and Croatia (Bega, 2015;Fantoni & Franciosi, 2010;Velić et al, 2015;Wrigley et a...…”

Section: General Structure Of the External Zones Of The Orogenmentioning

confidence: 99%

“…Tectonic map of the External Zones of the Albanides and Hellenides highlighting the structure of the IZ in Albania and western Greece. This map includes information from multiple cartographic sources, mostly the following sources for Albania(Argnani, 2013;Argnani et al, 1993Argnani et al, , 1994Scrocca et al, 2022;Xhomo et al, 2002), Greece(Bornovas & Rondogianni-Tsiambaou, 1983; IFP, 1966;Kamberis et al, 2000Kamberis et al, , 2013, offshore Albania(Fantoni & Franciosi, 2010;Kokinou et al, 2005Kokinou et al, , 2006, offshore areas from Zakynthos to Corfu(Birch, 1990;Brooks & Ferentinos, 1984;Chamot-Rooke et al, 2005;Cushing, 1985;Fournillon et al, 2017;Karakitsios, 2013;Makris & Papoulia, 2014;Papoulia & Makris, 2010;Underhill, 1988Underhill, , 1989Wardell et al, 2014), Gulf of Corinth(Bell et al, 2008;Palyvos et al, 2005;Zygouri et al, 2008), and active and recent faults(Brooks et al, 1988;Kassaras et al, 2020;Lekkas et al, 1997;Ntokos, 2018;Roberts & Jackson, 1991;Tranos et al, 2020). The approximate boundary between the Apulian and the Pre-Apulian (PrA) carbonate platforms with the South-Apulian Basin is taken from DelBen et al (2015).…”

mentioning

confidence: 99%

Contrasting Styles of Salt‐Tectonic Processes in the Ionian Zone (Greece and Albania): Integrating Surface Geology, Subsurface Data, and Experimental Models

Soto,

Tranos,

Bega

et al. 2024

Tectonics

View full text Add to dashboard Cite

The Ionian Zone (IZ) is one of the key elements of the fold and thrust belt (FTB) of the Albanian and Hellenides orogen and contains large outcrops of Triassic evaporites. The IZ consists of various thrust sheets with a general westward vergence, stacking over the Apulian and Pre‐Apulian zones, and repeating a thick carbonate sequence of Upper Triassic to Eocene age. Thrusting becomes younger toward the west with a piggyback sequence, starting during the latest Oligocene Epoch in the Internal Ionian and ending in the Pliocene in the External Ionian. We have studied the IZ in southern Albania and northwestern Greece using field observations and borehole data and by fully interpreting a recently acquired 2D seismic data set. Our objectives are to establish the geometry and nature of the contacts associated with the major Triassic outcrops, to unravel precursor salt diapirs, and to assess their role during the Alpine contraction. Salt structures include gentle salt pillows, isolated salt plugs and diapirs, thrust welds, and salt walls. Combining these observations with experimental modeling results, we show how these structures control the geometry and kinematics of the Alpine thrusts or the location and kinematics of recent strike‐slip faults. Salt minibasins have also been identified, demonstrating salt mobility conditioned Mesozoic sedimentation in the Ionian Basin. The use of salt‐tectonics principles to evaluate the structural style and evolution of the IZ FTB also opens new directions for interpreting the subsurface structure and evolution of the region.

show abstract

Tectonic Processes and Crustal Evolution on/Offshore Western Peloponnese Derived From Active and Passive Seismics

Abstract: We developed velocity models of the crust and sediments offshore south western Greece,

Cited by 3 publications

References 12 publications

Seismic imaging of fluid-filled inherited structures of the Northern Thessaly (Greece) seismic gap

Seismic imaging of fluid-filled inherited structures of the Northern Thessaly (Greece) seismic gap

Clusty, the waveform-based network similarity clustering toolbox: concept and application to image complex faulting offshore Zakynthos (Greece)

Contrasting Styles of Salt‐Tectonic Processes in the Ionian Zone (Greece and Albania): Integrating Surface Geology, Subsurface Data, and Experimental Models

Contact Info

Product

Resources

About