Earthquake focal mechanism analysis of Central Anatolia

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2018
Birsoy, Seda
Anatolian interior is characterized by large lateral and vertical displacements and a complex tectonic history. Especially, Central Anatolia is located between escape tectonics in the east and extensional deformation in the west. The nature of this transition is still under much debate and requires detailed analysis of active tectonic stresses within the region. In this study, regional moment tensor inversion is performed for 29 earthquakes with M>3.5 recorded between 2013-2015 by a temporary broadband seismic network. Resultant focal mechanisms are later used for stress tensor inversion to map the active stress field. Our focal mechanisms solutions indicate dominantly strike-slip and normal faulting across the region. Stress analysis conducted for sub-regions revealed strike-slip regime along East Anatolian Fault Zone (EAFZ) and across the interior parts of Anatolian plate (North of 38° latitude) where maximum principle stress (σ1) rotates clockwise from NW-SE to NE-SW towards east. On the other hand, earthquakes occurring near Adana Basin and İskenderun Gulf where three plates merge, display scattered seismicity and high (>35%) CLVD components associated to tectonic complexity and principal stress directions support a transtensional regime producing simultaneous NE-SW trending left-lateral strike-slip and E-W trending normal faulting.

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Citation Formats
S. Birsoy, “Earthquake focal mechanism analysis of Central Anatolia,” M.S. - Master of Science, Middle East Technical University, 2018.