Implications of 2007’s Earthquake Activity in Eğirdir Lake (SW Anatolia) Based on Moment Tensor Solutions and Inversion of Stress State
We analyzed the waveforms of the small- to moderate-sized earthquakes that took place in the northern part of the inner Isparta Angle (IA) to retrieve their source parameters and combine these results with the focal mechanism solutions of the larger events that occurred in 2007 in Eğirdir Lake at the apex of IA. In total, source mechanisms of 20 earthquakes within the magnitude range 3.5 < M < 5.0 were calculated using a regional moment tensor inversion technique. The inversion of the focal mechanisms yields an extensional regime with a NNE–SSW (N38°E) trending σ 3 axis. Inversion results are related to a mainly WNW–ESE oriented normal fault beneath Eğirdir Lake. The R value of a NNE–SSW extensional regime is 0.562 showing a triaxial stress state in the region. The current stress regime results from complex subduction processes such as slab pull, slab break-off, roll-back and/or retreating mechanism along the Hellenic and Cyprus arcs and the southwestward extrusion of the Anatolian block since the early Pliocene.
KeywordsMoment Tensor African Plate Triaxial Stress State Moment Tensor Solution Moment Tensor Inversion
The authors would like to thank Elif Tolak Çiftçi and Uğur Mustafa Teoman for their contributions. To improve the manuscript, we would also like to thank to the rewivers. This research was supported by Istanbul University Scientific Research Project (Project No: T-673/30062005). Most of the figures were created using the Generic Mapping Tools (GMT) software prepared by Wessel and Smith (1998).
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