THE BIGNOL, EASTERN TURKEY, EARTHQUAKE. CO-SEISMICPHENOMENA AND DAMAGE DISTRIBUTION

摘要

On May 1, 2003 a large catastrophic and deadly earthquake (Mw=6.4), occurred at the Eastern Turkey,some Km to the North of Bingol city. The large scale tectonics of the region is controlled by the collisionbetween the Eurasian and Arabian plates. This is the result of the northward motion of the Arabian plate,relative to Eurasia, which also causes the lateral escape of the Anatolian block to the West. The Anatolianblock is bounded to the North by the North Anatolian Fault (NAF) and to the South by the East AnatolianFault (EAF). These two branches of the Anatolian Fault System cross cut to the east at Karliova triplejunction point. The recent Bingol earthquake occurred near the eastern part of the EAF.The field work data show that the tectonic pattern of this area is very complicated and is representing bothby NE-SW or NW-SE strike-slip faults and N-W normal faults. According to the fault plane solution thisearthquake may have been the result either of the reactivation of a part of the NE-SW trending EAF or ofthe reactivation of someone of the NW-SE faults crossing the area. Although the aftershock distributionpattern, with M>2, is scattered, the distribution of the main aftershocks, with M>4.5 follows a clear NWSEdirection.A zone of co-seismic strike-slip, right-lateral surface ruptures, trending to the NW-SE direction, observed15-20 Km to the North of Bingol city. The distribution of landslides, rock falls and settlements, whichtook place during the seismic event, also follow the same direction. All these data suggest the reactivationof a NW-SE trending right-lateral, strike-slip fault to the North of Bingol.