COMPARISON OF PALAEOSTRESS ANALYSIS, GEODETIC STRAIN RATES AND SEISMIC DATA IN THE WESTERN PART OF THE SULTANDAGI FAULT IN TURKEY

The Sultandagi Fault is an active dip-slip normal fault bounding the southeastern border of the NW-SE striking Afyon-Aksehir Graben, an actively growing rill area in western Anatolia. The historical and instrumental earthquake record suggest the existence of a large number of earthquakes that created surface niptures in this system. The recent activities of the Sultandagi Faul (were evidenced bytwo 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. The possible continuation of this earthquake migration towards the west, seismic gaps existing in the region. the presence of historical destructive earthquakes, and the 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 Sultandagi 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-Alqehir Graben are dip-slip normal faults and were shaped under a NW-SE and NE-SW-directed bimodal extensional tectonic regime during the Quaternary-Holocenethe period.