Slip Model of the 2020 Yutian (Northwestern Tibetan Plateau) Earthquake Derived From Joint Inversion of InSAR and Teleseismic Data

Abstract

Both InSAR and teleseismic P wave were used to resolve the ambiguity of fault geometry.2. The rupture nucleation point and origin time were clarified by a Bayesian bootstrap optimization inversion method.3. Rupture process of this earthquake was predominantly normal-slip with slight rightlateral strike-slip components.

Co‐ and Post‐Seismic Mechanisms of the 2020 Mw 6.3 Yutian Earthquake and Local Stress Evolution

“…The seismic moment released from the distributed sliding fault plane is 3.35 × 10 18 N·m, corresponding to a moment magnitude of Mw 6.29, which is almost consistent with that ( Mw 6.3) obtained by Li, Li, et al. (2021) by combining InSAR and teleseismic waveform data and that ( Mw 6.3) determined by the seismological methods from several agencies. The maximum coseismic slip that we obtained is larger than those of He et al.…”

“…(2020) and is more consistent with Li, Li, et al. (2021) and Yu, Wang, et al. (2020) who used variable dip angles to determine the sliding distribution.…”

“…The Indian plate is converging on the Eurasian plate at a rate of ∼46 mm yr −1 , causing continued uplift, crustal thickening and lateral‐extrusion of the Tibetan Plateau. The Baryan Har Block (BHB) is the most dominant seismically active area within the Tibetan Plateau (Figure 1a) (Deng et al., 2014; Li, Li, et al., 2021; Li et al., 2008). At the western boundary of the BHB, there are three large left‐lateral strike‐slip faults (i.e., the Altyn Tagh fault, the Kangxiwar fault and the Longmu Co‐Bangda Co fault), forming a unique and complex tectonic conjunction region in northwestern Tibetan Plateau (Figure 1b) (Elliott et al., 2010; Xu et al., 2013; Yuan et al., 2020).…”

“…The 2020 Mw 6.3 Yutian earthquake is another strong seismic event in the region following the 2008 Mw 7.2, 2012 Mw 6.2, and 2014 Mw 6.9 earthquakes. As an event occurred at a junction area with complex tectonic settings in northwestern Tibet, it has attracted widespread attention from scholars in the determination of the geometric parameters and slip distribution of the seismogenic fault and the Coulomb stress (He et al., 2020; Jia et al., 2021; Li, Li, et al., 2021; Yu, Wang, et al., 2020). Both He et al.…”

A possible characteristic of foreshocks derived from the evaluation of loading/unloading induced by earth tides

“…The earthquake catalogs were retrieved from the China earthquake networks Center (CENC). Their source models were listed in Table 1, which were from the China Earthquake Administration (CEA), Global CMT Catalog and Li et al (2021). The internal friction coefficient for the calculation of CFS is also 0.4.…”