Title: Comparison of Palaeostress Analysis, Geodetic Strain Rates and Seismic Data in the the Western Part of the Sultandağı Fault in Turkey
Abstract: The Sultandağı Fault is an active dip-slip normal fault bounding the southeastern border of the NW-SE striking Afyon-Akşehir Graben, an actively growing rift area in western Anatolia. The historical and instrumental earthquake record periods suggest the existence of a large number of earthquakes that created surface ruptures in this system. The recent activities of the Sultandağı Fault are two earthquakes that occurred on February 3, 2002 (Mw=6.3 and Mw=6.0) and caused a surface rupture up to 26 km along with an approximately 30 cm vertical displacement. Based on the possible continuation of this earthquake migration towards the west, seismic gaps existing in the region, the presence of historical destructive earthquakes and active faults reveal the seismic hazard around the province of Afyonkarahisar. In this study, we determined the fault activities and stress directions in the western part of the Sultandağı Fault by comparing the results from the Palaeostress analysis of fault segments, focal mechanism solutions of recent earthquakes and geodetic analysis. The geologic, geodetic and earthquake data all indicate that both northern and southern master faults of the middle part of the Afyon-Akşehir Graben are dip-slip normal faults and were shaped under a NW-SE and NE-SW-directed bimodal extensional tectonic regime during the Quaternary period.