On the Potential of Rapid Moment Magnitude Estimation for Strong Earthquakes in Sichuan–Yunnan Region, China, Using Real-Time CMONOC GNSS Observations

Abstract

Abstract High-rate (≥1 Hz) real-time Global Navigation Satellite Systems (GNSS) data have been now incorporated into earthquake early warning systems where dense GNSS network exists, like the United States west coast, Japan, and so on. In this manuscript, we exploit the potential of rapid moment magnitude (Mw) estimation in Sichuan–Yunnan region using GNSS records from Crustal Movement Observation Network of China (CMONOC) for seven magnitude (M) ≥ 6 events from 2011 to 2020. We find that currently it is still quite challenging to get reliable Mw using the peak ground displacement or peak ground velocity approach, which is caused by the sparse stations and probably the inaccurate scaling law itself. By contrast, the Mw estimations from focal mechanism grid search are all consistent with Global Centroid Moment Tensor catalog, even by one station. Considering the CMONOC network is going to be densified in the coming decade, it is expected that high-rate GNSS waveforms will play a more important role in fast postevent response.