Slip Deficit on the North Anatolian Fault: Implications for Pending Earthquakes Offshore Istanbul
Abstract
Slip deficit and its interaction with the earthquake activity have been investigated on the North Anatolian Fault Zone in the Marmara region using inter-seismic period GPS measurements and refined earthquake catalogues. In this frame, along-fault distribution of slip deficit has been compared with the background seismicity as well as available co-seismic slip models. Historical earthquakes verify that the slip rate was 20 mm/yr for the time period of AD 500-2000 along the target fault section. The results verify that highly coupled fault patches generated the highest co-seismic slip during the 1999 Izmit earthquake. Highly coupled fault patches host currently low background seismicity along the Sea of Marmara segments, e.g. the segment beneath Central Basin and Eastern (Çınarcık) Basin. Low-coupling patches, however, host high background seismicity, e.g. the segment beneath Western (Tekirdağ) Basin. Our model verifies segmentation of the NAFZ in the Sea of Marmara section: Slip deficit remains below 1.7 m beneath Western (Tekirdağ) Basin. It reaches up to 4.0 m and 5.4 m beneath Central and Eastern (Çınarcık) Basins, respectively. These segments have failed during 1766b, 1766a and 1509 earthquakes and currently have a potential to generate Mw 7.2, Mw 7.4 and Mw 7.5, respectively. Simultaneous rupture of the entire Sea of Marmara would generate a Mw 7.7 earthquake, although historical catalog suggests at least two or more pending earthquakes (Mw>7.0) during current episode.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.S44A..08O
- Keywords:
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- 4314 Mathematical and computer modeling;
- NATURAL HAZARDSDE: 7215 Earthquake source observations;
- SEISMOLOGYDE: 7221 Paleoseismology;
- SEISMOLOGYDE: 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICS