Slip rates and seismic moment deficits on major active faults in mainland China

Abstract

The Chinese mainland features widespread active faults and intensive seismic activity; both can be described in terms of slip rates on these faults. Previous studies of fault slip rates in mainland China have focused on individual faults or fault segments, and large discrepancies exist among results derived from different methods. Here we derive a self‐consistent estimate of the slip rates on all major faults in mainland China using the recently updated GPS data and an elastic block model. The predicted slip rates are high in western and low in eastern China, ranging from 25.1 ± 2.0 mm/yr in the Himalayan Thrust System to less than 1.0 mm/yr in north China. Using these slip rates, we estimated the rates of moment accumulation on the major fault zones and compared them with the seismic moment released on each fault zone using the Chinese historical earthquake catalog that extends for more than 2000 years in many regions. The results show nine seismic zones with large moment deficits (unreleased moment). Future refinement of GPS measurements and earthquake history will allow better estimates of slip rates on individual faults and better assessment of earthquake hazard on these faults in mainland China.

Reassessment of Stable Continental Regions of Southeast Asia

“…Geologic data including slip rates of individual faults indicate eastward movement with respect to Siberia of 1-2 mm/yr in the eastern half of the North China block and 2-4 mm/yr in the western half (Liu et al 2007). Geodetic data indicate rates consistent with those of Liu et al (2007) (Wang et al 2011).…”

“…This isolation allows the possibility that the southern Korean peninsula might be a small fragment of comparatively intact ACR crust that is being carried east-southeastward by Neogene extension of the surrounding more active continental crust. The possibility is consistent with the small horizontal relative motions and dilational strains between the southern part of the peninsula and adjacent ACRs to the west and southwest (Liu et al 2007;Wang et al 2011). The 1994 and 2011 versions of the China SCR extend as far offshore as 700 km southeast of Hainan Island (Figures 1, 2; Broadbent and Allan Cartography 1994).…”

“…The extension also requires reclassifying this part of the 1994 China SCR as active crust (Table 1). (Wang et al 2011). The continental margin is more seismically active than the South and North China blocks, especially west of Taiwan (Liu et al 2007;Wang et al 2011).…”

“…The Tanlu fault separates the Mongolia and 2011 China SCRs. The Mongolia SCR is moving eastward with respect to a fixed Eurasia (Liu et al 2007;Wang et al 2011). The relative motion takes place on a belt of extensional and left-lateral transtensional faulting north of the SCR, between it and the Siberian part of the Eurasian SCR.…”

Near-field motion of the Haiyuan fault zone in the northeastern margin of the Tibetan plateau derived from InSAR permanent scatterers analysis

“…Using geological methods and investigations of the features of the terrain around the fault, and using geological dating, the Holocene slip rates of various segments of the Haiyuan fault zone are estimated to be 3 to 10 mm∕year. [4][5][6][7] Most of the recent GPS measurements suggest that this fault zone is in a left-slip state at rates of 3 to 8 mm∕year, [8][9][10][11] though individual work reports slip rates of only 1.1 to 1.7 mm∕year. 12 The discrepancy in these geodetic estimations may be associated with differences in measurement sites, station spacing, and analysis methods.…”