Evolution of the crustal inner shear deficit in a reference to 2010-2023 Aegean Sea earthquakes
1 RUDN University, Moscow, Russia
2 Dokuz Eylul University, Izmir, Turkey
3 Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
Abstract
The animation provides a synoptic analysis of the evolution of internal crustal motion deficits associated with the 2011–2023 strong Aegean earthquakes and regional fault tectonics. The strongest event during this period was the Samos earthquake on 10/30/2022 (M7, Depth 21 km). The deficit of internal movements is the area of minimum modules of vectors of accumulated horizontal displacements of continuous GNSS stations in the inner coordinate system, independent of the general tectonic trend of movements of the region. Time series of GNSS station coordinates with an interval of one day were obtained from the Nevada Geodetic Laboratory website [Blewit et al., 2018]. In the animation, this area is colored dark brown, in accordance with the isoline color bar. The zone of deficiency of internal movements demonstrates their absence or smallness at the level of accuracy in determining displacements of ~2 cm. The epicenter areas of future strong earthquakes are marked with white circles before the events. This characteristic shows that in the region under study there are places that do not experience rapid movements, which is typical for “locked” compacted areas of the earth’s crust. In seismically active areas, such zones are zones of accumulation of elastic seismic energy. When a certain strength limit is reached, these zones are destroyed by a seismic rupture. The study of the evolution of such zones contributes to the study of the spatial kinematics of the accumulation of seismogenic stresses. Stress drop begins in the south-southeast of the region with the 2011-2012 M6 earthquakes. The depth of the source of the first event was 60 km, the second – 35 km. The movements are more intense near the epicenter of the first deep event. The GNSS station on Santorini Island receives the greatest accumulation of displacements. This may indicate the activation of deep-laid volcanic activity under the active volcanic region. The expansion of the destruction zone is accompanied by two seismic events M6.3-6.6 with hypocenter depths of 12 and 7 km, respectively. After these events, the area of internal displacement deficit concentrated in the center of the region, covering the site of the future epicenter of the Samos M7 earthquake. This earthquake destroys the middle part of the general area of small movements. The distribution of the area of deficit of internal movements occurs covering the axial line of the border between Aegean and Anatolian tectonic plates in the direction southwest - northeast. The strongest earthquake provoked a left-lateral shift of the territory of Turkey (Anatolian plate) to the north-northwest in relation to Greece (Aegean plate), which moved to the southeast.
Noteworthy are the areas of Chios Island and the coast of Turkey, where residual zones of displacement deficiency still remain.
Database creation date: 2024; Publication date: December 2024
Contributor:
Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
Institution: Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
Publisher: Geophysical Center of the Russian Academy of Sciences (GC RAS), Moscow, Russia (http://www.gcras.ru/eng/)
Data format: .m4v (M4V File Format)
doi: 10.2205/esdb-aegean-deficit
Citation: Kaftan V. I., Melnikov A. Yu., Dokukin P. A. (2024) Evolution of the crustal inner shear deficit in a reference to 2010-2023 Aegean Sea earthquakes, GCRAS, Moscow, https://doi.org/10.2205/esdb-aegean-deficit
References:
- Blewitt, G., Hammond, W. C., Kreemer C. Harnessing the GPS data explosion for interdisciplinary science. Eos, 99 (2018) https://doi.org/10.1029/2018EO104623.
License: 
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
URL for downloading: http://esdb.wdcb.ru/doi/2024/esdb-aegean-quake-2010-2023/Evolution_of_the_crust_inner_shear_deficit_in_a_reference_to_2010-2023_Aegean_Sea_earthquakes.m4v
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