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Spatiotemporal earthquake clusters along the North Anatolian fault zone offshore Istanbul

January 1, 2011

We investigate earthquakes with similar waveforms in order to characterize spatiotemporal microseismicity clusters within the North Anatolian fault zone (NAFZ) in northwest Turkey along the transition between the 1999 İzmit rupture zone and the Marmara Sea seismic gap. Earthquakes within distinct activity clusters are relocated with cross-correlation derived relative travel times using the double-difference method. The spatiotemporal distribution of microearthquakes within individual clusters is resolved with relative location accuracy comparable to or better than the source size. High-precision relative hypocenters define the geometry of individual fault patches, permitting a better understanding of fault kinematics and their role in local-scale seismotectonics along the region of interest. Temporal seismic sequences observed in the eastern Sea of Marmara region suggest progressive failure of mostly nonoverlapping areas on adjacent fault patches and systematic migration of microearthquakes within clusters during the progressive failure of neighboring fault patches. The temporal distributions of magnitudes as well as the number of events follow swarmlike behavior rather than a mainshock/aftershock pattern.

Publication Year 2011
Title Spatiotemporal earthquake clusters along the North Anatolian fault zone offshore Istanbul
DOI 10.1785/0120100215
Authors Fatih Bulut, William L. Ellsworth, Marco Bohnhoff, Mustafa Aktar, Georg Dresen
Publication Type Article
Publication Subtype Journal Article
Series Title Bulletin of the Seismological Society of America
Index ID 70036641
Record Source USGS Publications Warehouse
USGS Organization Earthquake Science Center