Slip rate and slip magnitudes of past earthquakes along the Bogd left‐lateral strike‐slip fault (Mongolia)

摘要: We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, principal structure involved in Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Fault is 260 km long and can be subdivided into five main geometric segments, based on variation strike direction. West East these segments are, respectively: Ih (WIB), North (NIB), Baga (WBB) (EBB) segments. Morphological analysis offset streams, ridges alluvial fans-particularly well preserved arid environment Gobi region-allows evaluation late Quaternary slip rates different faults In this paper, we measure over past 200 ka at four sites distributed across three western Fault. Our results show that rate similar 1 mm yr(-1) WIB EIB 0.5 NIB segment. These variations are consistent with restraining bend geometry Fault.;Our study also provides additional estimates horizontal associated part rupture, complementing previously published studies. mean decreases progressively 5.2 m west 2.0 east, reflecting progressive change kinematic style pure faulting left-lateral-reverse faulting. Along cumulative displacements multiples coseismic offset, which may a characteristic slip. Moreover, using data, re-estimate moment magnitude M-w 7.78-7.95.;Combining our distribution per event determined recurrence interval 2500-5200 yr for earthquakes This suggests Gurvan Bulag thrust fault (a reverse bounding southern side ruptured during earthquake) have average times, therefore together previous as they did 1957. suggest system, including fault, usually behaves 'characteristic earthquake' mode.