HR: 11:35h
AN: T52B-06    [Abstracts]
TI: Seismotectonics of the Cyprus Arc and Dead Sea Fault Zone: Eastern Mediterranean
AU: * Yolsal, S
EM: yolsalse@itu.edu.tr
AF: Istanbul Technical University, Faculty of Mines, Department of Geophysics, Ayazaga Campus, Maslak, Istanbul, 34390 Turkey
AU: Taymaz, T
EM: taymaz@itu.edu.tr
AF: Istanbul Technical University, Faculty of Mines, Department of Geophysics, Ayazaga Campus, Maslak, Istanbul, 34390 Turkey
AB: This presentation is concerned with the seismotectonics of Cyprus Arc, Dead Sea Fault Zone, and surrounding regions that are prominent features in the collision zone between the African and Arabian plates accommodating the relative motion between the plates, and provides us with a relatively simple pattern of deformation. Seismotectonics of the Eastern Mediterranean region is evolved as a result of the interaction between the African, Arabian and Eurasian plates. Most of the seismic activity are concentrated and released along the major tectonic boundaries: Dead Sea Transform Fault, Hellenic and Cyprus Arcs, the East and North Anatolian Faults and Bitlis-Zagros suture zone. The Cyprus Arc extends from the Antalya Bay to the Gulf of Iskenderun (SE Turkey), eventually reaching East Anatolian Fault Zone. The nature of relative motion and the geometry of Cyprus Arc, and Dead Sea Fault Zone have been closely examined. We have studied the tectonic characteristics of a comprehensive seismicity occurred in the region during the last 15 years, based on newly retrieved and obtained source mechanisms and rupture histories of $\sim$15 earthquakes, M$_w$$>$5.3, by using waveform inversion of teleseismic long-period P-, SH-, and broad-band P-waveforms recorded in the distance range of 30-90$\deg$, for which signal amplitudes were large enough, with synthetic waveforms. Seismograms are generated by combining direct (P, S) and reflected (pP and sP or sS) phases from a point source embedded in a given velocity structure. The solutions were also constrained by P-wave first motion polarities of near-field stations, and InSAR data where available. Source mechanisms exhibit the characteristics and structural complexities associated with strike-slip, thrust and normal faulting as a result of ongoing crustal deformation. The character of the faulting along the Dead Sea Fault Zone exhibits mainly left-lateral strike-slip faulting with normal component that is in a good agreement with the geology and neotectonic features of the region. In the Gulf of Aqaba region, focal depth of earthquakes become shallower and scarcely reaches to the lower crust. Focal depth distribution exhibits the thinning of the seismogenic zone in the south that is probably related to the increase in the heat flow distribution towards the Red Sea. At the southwestern part of Cyprus, most of the mechanisms show right-lateral strike-slip faulting with thrust component, but some earthquakes with shallow focal depths confirm the normal faulting with strike-slip component.
DE: 7230 Seismicity and seismotectonics
DE: 8107 Continental neotectonics
DE: 8123 Dynamics, seismotectonics
DE: 7203 Body wave propagation
DE: 7215 Earthquake parameters
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting