Rupture Process of the 2022 Mw6.6 Menyuan, China, Earthquake from Joint Inversion of Accelerogram Data and InSAR Measurements

oleh: Chuanchao Huang, Guohong Zhang, Dezheng Zhao, Xinjian Shan, Chaodi Xie, Hongwei Tu, Chunyan Qu, Chuanhua Zhu, Nana Han, Junxian Chen

Format: Article
Diterbitkan: MDPI AG 2022-10-01

Deskripsi

We obtained the rupture process and slip distribution of the 2022 Mw6.6 Menyuan earthquake by jointly inverting accelerogram data and InSAR measurements. The near-field InSAR measurements provide good constraints on the shallow slip distributions (<6 km). The accelerogram data enable us to better resolve the deeper coseismic slip (>6 km). The combination of two types of data provided improved constrains on slip distribution of the 2022 Menyuan earthquake. The results from joint inversion of InSAR and accelerogram data reveal a 26-km-long rupture length, which roughly agrees with the mapped length from the optically identified surface rupture trace and the InSAR deformation field. We imaged a major asperity with a dimension of 14 × 6 km at 4 km depth updip of the hypocenter. The maximum slip is estimated to be 3.8 m at 4 km depth. The duration of the 2022 Menyuan earthquake is ~14 s, and 90% of the seismic moment is released in the first 10 s. The total seismic moment is estimated to be 1.31 × 1 × 10<sup>19</sup> N·m, equivalent to a moment magnitude of Mw6.7. Our results highlight that the moderate but shallow rupture during the 2022 Menyuan earthquake could intensify the seismic damage on the surface, confirmed by field investigations.