Abstract
To investigate the reliability of high-rate GNSS in the rapid inversion of source parameters for the 2022 Menyuan Mw 6.6 earthquake, we collected high-rate GNSS and strong motion data within a 200 km radius of the epicenter. We performed high-precision calculations to obtain three-dimensional dynamic displacement waveforms for all stations and analyzed the reliability of coseismic deformation acquisition and source parameter inversion. The three-dimensional dynamic displacement waveforms show that the amplitude of displacement fluctuations at each station decreases with increasing distance from the epicenter. At the closest station to the epicenter, C007, the maximum amplitude in the east-west direction reached 15 cm, while the maximum amplitude in the north-south direction reached 10.8 cm. The inverted epicenter location using displacement waveforms is (101.263°E, 37.802°N), with an origin time of 17:45:25.9 (UTC) and a magnitude of Mw 6.65. These results are generally consistent with those obtained from seismological methods using seismic wave information. Based on the displacement waveforms 100 seconds before and after the earthquake, the horizontal coseismic deformation of this event can be quickly obtained. The results show opposite motion trends on the south and north sides of the seismogenic fault, with no significant vertical movement, indicating that the earthquake is predominantly characterized by left-lateral strike slip motion. The results indicate that using near-field high-rate GNSS and strong motion data can rapidly and effectively invert strong earthquake source parameters and coseismic deformation results. This can provide valuable reference for post-earthquake emergency response and rapid disaster assessment.