Abstract
We present the source mechanisms and rupture processes for the damaging 23 February 2020 earthquake doublet of Mw 5.8 and Mw 5.9 that occurred near the Turkish-Iranian border regions of Qotur-Goharan-Mir'Omar-Ravian (NW Iran), extending towards Saray and Başkale (Eastern Turkey), as obtained from seismological waveform analysis and space geodesy imaging. Seismotectonic characteristics of the sequence highlight the role of indentation tectonics developed within regional-scale compressional environment where the Arabian microplate collides with the Eurasian plate. Here we report optimal finite-fault slip distribution patterns of the 2020 Qotur-Ravian earthquake doublet revealing complex co-seismic rupture propagation along the fault planes with maximum displacements ranging from 20 to 50 cm, stretching from the hypocentre to the surface. Analysis of aftershocks based on 3.5 months-long seismicity confirms distributed deformation. This energetic earthquake sequence demonstrates the distinct rupture characteristics illuminating differences in seismogenic properties and seismic hazard. Coulomb stress transfer modelling predicts triggering of the second event of Mw 5.9 by the first event of Mw 5.8. The zone of Coulomb stress changes attributed to varying pore pressure linking to geothermal water resources in the region as a driving force, may have an impact on the nucleation of triggered faulting. Evaluation of Interferometric Synthetic Aperture Radar (InSAR) data reveals the activated faults with evident co-seismic slip. Specifically, (1) we detected a rare case in earthquake-induced ground deformation where there is overlapping surface deformation due to sequential shallow events located closely in the crust, (2) the initial event ruptured a normal fault located towards W-NW of the latter inferred strike-slip fault and (3) the conjugate system of faults is closely placed at a few km apart. The frequent Sentinel-1 interferograms enhanced our imaging abilities of geometry and kinematics of shallow moderate-size M < 6.0 earthquakes and to trace seismogenic structures in remote and mountainous earthquake prone regions.
Original language | English |
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Article number | 229482 |
Journal | Tectonophysics |
Volume | 838 |
DOIs | |
Publication status | Published - 5 Sept 2022 |
Bibliographical note
Publisher Copyright:© 2022 Elsevier B.V.
Funding
We gratefully acknowledge the Disaster and Emergency Management Presidency of Türkiye (AFAD) providing initial catalogue of aftershocks and phase-arrival data acquired from their bulletin resources for the period 23 February 2020–13 June 2020. We also thank Ali Mouradi (Institute of Geophysics, University of Tehran, Iran) for providing initial catalogue of aftershocks and phase-arrival data acquired from bulletin resources of national earthquake network of Iran for the period 23 February 2020–26 March 2020. The IRIS Data Management Centre were used for access to teleseismic waveforms. We thank ESA, Geohazards Lab and Terradue for providing access to Geohazards Exploitation Platform (GEP– https://geohazards-tep.eu) for InSAR cloud processing. Athanassios Ganas and Vasilis Kapetanidis thank “HELPOS - Hellenic Plate Observing System” (MIS 5002697) which is funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). We thank Istanbul Technical University Research Fund, the National Scientific and Technological Research Council of Türkiye (TÜBİTAK), Turkish Academy of Sciences (TÜBA) in the framework for Young Scientist Award Program (TÜBA-GEBİP), the Science Academy Chamber–Türkiye (BAGEP), and the Alexander von Humboldt Foundation Research Fellowship Award for financial support and for further providing computing facilities and other relevant computational resources through Humboldt-Stiftung Follow-Up Programme. We have further benefited from fruitful discussions with Ömer Emre, Onur Köse, Taylan Öcalan and Ilektra Karasante for computational support and interpretation of neotectonics features observed and for structural damages reported in the catastrophic area. Communications with Mohammad Faridi (July 2020; GSI, Tabriz), Esmaeil Farzanegan (August 2020, ISMN, Tehran) and the Western Azarbaijan Crisis Management Office (Urumiyeh, Iran) are greatly appreciated. Manuel Berberian's research was not supported by any grant, organization or individual. Cyrus Esmaeili was supported by the Geological Survey of Iran (GSI) north-western regional office at Tabriz, Iran. We are grateful to the Editor-in-Chief Gregory Houseman and the reviewers Jiří Zahradník and an anonymous one for their valuable comments, constructive advice and suggestions of judicial reviews that resulted in significant improvement of this manuscript. Tuncay Taymaz thanks Beyza Taymaz for her help in Persian literature. We gratefully acknowledge the Disaster and Emergency Management Presidency of Türkiye (AFAD) providing initial catalogue of aftershocks and phase-arrival data acquired from their bulletin resources for the period 23 February 2020–13 June 2020. We also thank Ali Mouradi (Institute of Geophysics, University of Tehran, Iran) for providing initial catalogue of aftershocks and phase-arrival data acquired from bulletin resources of national earthquake network of Iran for the period 23 February 2020–26 March 2020. The IRIS Data Management Centre were used for access to teleseismic waveforms. We thank ESA, Geohazards Lab and Terradue for providing access to Geohazards Exploitation Platform (GEP– https://geohazards-tep.eu ) for InSAR cloud processing. Athanassios Ganas and Vasilis Kapetanidis thank “HELPOS - Hellenic Plate Observing System” (MIS 5002697) which is funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). We thank Istanbul Technical University Research Fund, the National Scientific and Technological Research Council of Türkiye (TÜBİTAK), Turkish Academy of Sciences (TÜBA) in the framework for Young Scientist Award Program (TÜBA-GEBİP), the Science Academy Chamber–Türkiye (BAGEP), and the Alexander von Humboldt Foundation Research Fellowship Award for financial support and for further providing computing facilities and other relevant computational resources through Humboldt-Stiftung Follow-Up Programme. We have further benefited from fruitful discussions with Ömer Emre, Onur Köse, Taylan Öcalan and Ilektra Karasante for computational support and interpretation of neotectonics features observed and for structural damages reported in the catastrophic area. Communications with Mohammad Faridi (July 2020; GSI, Tabriz), Esmaeil Farzanegan (August 2020, ISMN, Tehran) and the Western Azarbaijan Crisis Management Office (Urumiyeh, Iran) are greatly appreciated. Manuel Berberian's research was not supported by any grant, organization or individual. Cyrus Esmaeili was supported by the Geological Survey of Iran (GSI) north-western regional office at Tabriz, Iran. We are grateful to the Editor-in-Chief Gregory Houseman and the reviewers Jiří Zahradník and an anonymous one for their valuable comments, constructive advice and suggestions of judicial reviews that resulted in significant improvement of this manuscript. Tuncay Taymaz thanks Beyza Taymaz for her help in Persian literature.
Funders | Funder number |
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BAGEP | |
Esmaeil Farzanegan | |
ISMN | |
Istanbul Technical University Research Fund | |
National Scientific and Technological Research Council of Türkiye | |
Science Academy Chamber–Türkiye | |
TÜBA | |
TÜBA-GEBİP | |
Western Azarbaijan Crisis Management Office | |
Alexander von Humboldt-Stiftung | |
European Commission | |
European Space Agency | |
Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | |
Türkiye Bilimler Akademisi | |
European Regional Development Fund | |
Geological Survey and Mineral Exploration of Iran |
Keywords
- Active tectonics
- Continental strike-slip faulting
- Earthquake source mechanisms
- East Anatolia and NW Iran
- Satellite geodesy
- Slip history