Earthquake Magnitude Estimation from High-Rate GNSS Data: A Case Study of the 2021 Mw 7.3 Maduo Earthquake

Abstract

Peak ground displacement (PGD) and peak ground velocity (PGV) are critical parameters during earthquake early warning, as they can provide rapid magnitude estimation before rupture end. In this study, we used the high-rate Global Navigation Satellite System (GNSS) data from 55 continuous stations to estimate the magnitude of the 2021 Maduo earthquake in western China. We used the relative positioning method and variometric approach to acquire real-time GNSS displacement and velocity waveforms, respectively. The results showed the amplitude of displacement and velocity waveforms gradually decreased with increasing hypocentral distance. Our results showed that the fluctuation of PGD magnitudes over time is smaller than that of PGV magnitudes. Nonetheless, the earthquake magnitudes estimated from both methods were consistent with their counterparts (Mw 7.3) reported by the United States Geological Survey (USGS). The final magnitude estimated from the PGD and PGV methods were Mw 7.25 and Mw 7.31, respectively. In addition, our results highlighted how the number of high-rate GNSS stations could influence the stability and convergence time of magnitude estimation.

Fast 1-D Velocity Optimization Inversion to 3D Velocity Imaging: A Case Study of Sichuan Maerkang Earthquake Swarm in 2022

“…From the relocation results, we found that the aftershock sequence of the Maerkang earthquake moved southeastward and deeper underground (Figure 6). According to the analysis of regional tectonic stress research results, this is mainly due to the influence of the enormous stress environment of the block extrusion on the Tibetan Plateau, Like most other earthquakes in the Qinghai Tibet Plateau [49,50]. When the crustal material of the Tibetan Plateau migrated eastward, it was obstructed by the hard Sichuan Basin in the east to generate stress accumulation.…”

Effects of Strong Earthquake on Plant Species Composition, Diversity, and Productivity of Alpine Grassland on Qinghai-Tibetan Plateau

“…According to the China Earthquake Information Network ( http://www.csi.ac.cn/ ), Maduo earthquake has the focal depth of 17 km, and the average altitude of 4,200 m within 10 km of the epicenter. Up to date, many scholars have kept on studying on the occurrence mechanism and induced geohazards of the 2021 Maduo earthquake (Chen et al, 2021 ; Gao et al, 2021 ; Wang et al, 2021 ; Zhu et al, 2021 ). However, we still know less about how will plant community responds to the earthquake in alpine grassland.…”

Simultaneous Rupture Propagation Through Fault Bifurcation of the 2021 Mw7.4 Maduo Earthquake

“…The left‐lateral strike‐slip Mw7.4 Maduo earthquake occurred on 21 May 2021, rupturing the near E‐W oriented JiangCuo fault, which is located within the Bayan Har block (Zhan et al., 2021) in the northeastern Tibetan Plateau (Figure 1b). The earthquake was well‐recorded in space geodetic images (He et al., 2022; J Liu et al., 2022) and nearby static (M. Wang, Wang, et al., 2022) and high‐rate Global Positional System (GPS) offsets (Gao et al., 2021). Earlier reports of the earthquake show that this was a bilateral rupture, which propagated ∼80 km to both sides of the epicenter (He et al., 2022; Ren et al., 2022; S. Wang, Song, et al., 2022).…”