Three-Dimensional Surface Displacements of the 8 January 2022 Mw6.7 Menyuan Earthquake, China from Sentinel-1 and ALOS-2 SAR Observations

Jihong Liu,Zhiwei Li,Zhangfeng Ma,Wenbin Xu,Jun Hu,Qian Sun,Jianwen Shi

doi:10.3390/rs14061404

Jihong Liu, Zhiwei Li + Show 5 more

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https://doi.org/10.3390/rs14061404

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Journal: Remote Sensing	Publication Date: Mar 14, 2022
Citations: 20	License type: CC BY 4.0

Affiliation: Hohai University, Central South University

Abstract

The 8 January 2022 Mw6.7 Menyuan earthquake was generated in the transition zone between the western Lenglongling fault and the eastern Tuolaishan fault, both being part of the Qilian–Haiyuan fault system with an important role in the adjustment of the regional tectonic regime. In this study, four pairs of SAR (synthetic aperture radar) data from Sentinel-1 and ALOS-2 (Advanced Land Observation Satellite-2) satellites were used to derive the surface displacement observations along the satellite line-of-sight (LOS) and azimuth directions using the differential interferometric SAR (InSAR, DInSAR), pixel offset-tracking (POT), multiple aperture InSAR (MAI), and burst overlap InSAR (BOI) methods. An SM-VCE method (i.e., a method for measuring three-dimensional (3D) surface displacements with InSAR based on a strain model and variance component estimation) was employed to combine these derived SAR displacement observations to calculate the 3D co-seismic displacements. Results indicate that the 2022 Menyuan earthquake was dominated by left-lateral slip, and the maximum horizontal and vertical displacements were 1.9 m and 0.6 m, respectively. The relative horizontal surface displacement across the fault was as large as 2–3 m, and the fault-parallel displacement magnitude was larger on the southern side of the fault compared with the northern side. Furthermore, three co-seismic strain invariants were also investigated, revealing that the near-fault area suffered severe deformation, and two obviously expanding and compressed zones were identified. We provide displacements/strains derived in this study in the prevailing geotiff format, which will be useful for the broad community studying this earthquake; in addition, the SM-VCE code used in this study is open to the public so that readers can better understand the method.

Highlights

At 1:45:30 a.m. on 8 January 2022, an Mw = 6.7 earthquake occurred about54 km northwest of Menyuan county, Qinghai province, China with a focal depth of about10 km [1,2]
It is easy to infer that this earthquake was dominated by left-lateral strike slip, which is consistent with the overall tectonic movement of the Qilian–Haiyuan fault system (QHFS)
This may be attributed to the fact that, across the QHFS, the Qinghai–Tibet Plateau block on the southern side of this fault system is relatively active and continuously pushing northward, but being resisted by the Gebi–Alashan block and the Huabeikelatong block, which are relatively stable compared with the Qinghai–Tibet

Summary

Introduction

The QHFS comprises from west to east the following structures: the TF, LEF, Jinqianghe fault (JF), Maomaoshan fault (MF), Laohushan fault (LAF), and Hauyuan fault (HF) [3]. This fault system is generally characterized by left-lateral slip and is one of the most important fault systems in the northeastern boundary of the Qinghai–Tibet Plateau block [4]. In this fault system, the northeastward movements of the Qinghai–Tibet Plateau block are resisted by the Gebi–Alashan block and Remote Sens.

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