Evaluation of gravitational anomalies in the areas of strongest earthquakes based on GRACE satellite measurements

A method for extracting the pre-seismic gravity anomalies over the Tibetan Plateau based on the maximum shear strain using GRACE data

“…Before and after the 1964 Alaska earthquake, the 1965-1967 Songdai earthquake swarm in Japan, the 1974 Izu earthquake in Japan, the 1976 Gazley earthquake swarm in the Soviet Union, and the 2013 M s 7.0 Lushan earthquake and gravity drop after the mainshock (Barnes, 1966;Wang LH et al, 2023Zhu YQ et al, 2023, the time-varying information on gravity before earthquakes was observed with time series of absolute and relative gravity data. The gravity data obtained by the Gravity Recovery And Climate Experiment (GRACE), which is representative of gravity satellite technology, contains information on the crustal density distribution and can be used to study the interaction mechanism between and within plates before earthquakes (Wahr et al, 1998;Peidou and Pagiatakis, 2019;Zotin et al, 2019;Gido et al, 2020;Velicogna et al, 2020;Liu C and Sun WK, 2023). Sun W and Okubo (2004) studied whether the GRACE satellites could detect coseismic gravity changes based on dislocation theory and concluded that GRACE is capable of detecting coseismic deformation signals from earthquakes with a magnitude greater than 7.5.…”