THE 17 AUGUST 1999 GOELCUEK (KOCAELI)- ARIFIYE (ADAPAZARI) AND 12 NOVEMBER 1999 DUEZCE EARTHQUAKES, NW TURKEY: THEIR MECHANISMS AND TECTONIC SIGNIFICANCE

摘要

17 August 1999 Goelcuek (Kocaeli)-Arifiye (Adapazan) earthquake (Mw=7.4) occurred along the western part of the North Anatolian Fault Zone. The earthquake was centered at 40.702°N, 29.987°E and originated at a depth of 17 km. The earthquake created a 160 km long surface rupture in a right-lateral sense of shear and exhibits two large displacements at two geographic locations that are about 70 km apart. The displacements are 4.1 m at Goelcuek and 4.9 m in the south of Arifiye. An inversion analysis of seismic data suggests a two-stage fracturing. 12 November Duezce earthquake (Mw=7.1) occurred to the east of Goelcuek-Arifiye line and created a 38 km long surface rupture. The maximum rigth-lateral displacement of 4.5 m occurred in the middle of the surface rupture. To the south of Duezce, the surface ruptures of two earthquakes overlapped by about 10 km length. Duezce earthquake must have been triggered by Goelcuek-Arifiye earthquake.