The December 2nd, 2015 Bingöl, Eastern Anatolia-TURKEY, earthquake (Mw = 5.3): A rupture on optimally oriented fault plane

Abstract

Eastern Anatolia is a ∼2 km high plateau shaped by the continent-continent collision of the Arabian and Eurasian plates. The left lateral East Anatolian Fault Zone, the right lateral North Anatolian Fault Zone and the Bitlis fold-thrust belt are the major tectonic boundaries of this convergence zone. The Arabian-Eurasian collision has resulted in high volcanism and well recorded seismic activity in Eastern Anatolia and its surroundings. Karlıova Junction is located at the intersection of these major fault systems and contains secondary faults such as the Karakoçan fault and the Sancak-Uzunpınar fault. We processed high quality waveform data collected from a recent seismic activity in the proximity of the city of Bingöl where the largest event is the moderate-size earthquake (Mw = 5.3) occurred on 2 December 2015. This event is located to the west of Karlıova Junction and to the northwest of Sancak-Uzunpınar fault. The spatial distribution of the aftershocks points out unmapped faults with NNW-SSE alignment towards the west of Sancak-Uzunpınar fault. Aftershock depth distribution indicates a nearly 15 km deep brittle seismogenic zone. The relocated aftershock distributions and seismic moment calculations yield a rupture area 9 km in length and 5 km in width with an average 8 cm of slip. The latest four earthquakes preceding the 2015 Eq with magnitudes larger than Mw > 6 enhanced the Coulomb stress failure in the 2015 Bingöl Earthquake rupture area. The ruptured fault plane is in-line with the optimally oriented right-lateral strike-slip faults.