• 标题：Variations in Locking Along the East Kunlun Fault, Tibetan Plateau, China, Using GPS and Leveling Data
• 关键词：East Kunlun Fault, fault locking, GPS, leveling.
• 作者：LIANGYU ZHU, LINGYUN JI, and FENGYUN JIANG

全文下载

Abstract—The East Kunlun Fault (EKF) is one of the largest and most active sinistral strike-slip faults in the Qinghai–Tibet Plateau. Since 1900, many earthquakes of magnitude [7 have occurred in this region. The Maqin–Maqu Segment (MMS), a seismic gap underlying a densely populated zone, is particularly important. While the area has been extensively researched to assess seismic risk, refifined asperity geodetic imaging is defificient. We combined multiple sets of GPS and leveling observations to obtain spatial–temporal distributions of locking along the EKF. We delineated the probable asperity ranges according to the fault plane locking and the distribution of small earthquakes. Long-term observations on GPS velocity (1999–2013) and leveling (1970–2013) indicate that the Dulan–Maduo segment (DMS) of the EKF has a 140-km-long strong coupling section, and both the MMS and the eastern Ruoergai segments have a 40-km-long locking range. The 2013–2015 GPS velocity observations show that from Maqu to Maqin, the locked DMS and MMS lengths increased to 200 km and 240 km, respectively, while the locked eastern Ruoergai segment decreased and migrated 60 km to the west. This change in locking over time implies that the post-seismic effects of surrounding earthquakes have had signifificant impacts on the EKF. The locking area derived from 2015 to 2017 GPS velocity shows a growing trend and indicates the connectedness between the two speculative asperities. Combining the distribution of historical earthquakes and the precision positioning of small earthquakes, we conclude that the geodetic imaging of the EKF indicates that the MMS and DMS are high-risk zones for destructive earthquakes.