Tittle: Coseismic Gravity Gradient Changes in a Spherical Symmetric Earth Model: Application to the 2011 Tohoku-Oki Earthquake
Abstract: In this study, a new approach for the computation of coseismic gravity gradient changes in a spherically symmetric Earth model is presented. We derived the mathematical expressions of gravity gradient changes based on the Green's functions for four independent seismic sources. The results obtained from numerical computations and those calculated using the flat-Earth model are in good agreement within a near field, verifying that our computing scheme is valid, while the differences in the far field show the advantages of the spherical model. Furthermore, the proposed method was applied to analyze the coseismic gravity gradient changes caused by the 2011 Tohoku-Oki earthquake. The theoretical gravity gradient changes agree well with the Gravity Recovery and Climate Experiment observations, indicating that the proposed dislocation theory is important and can be used to efficiently interpret seismic deformations. In addition, the contribution of seawater was discussed.
Citation: Ji, Y., Tang, H., & Sun, W. (2022). Coseismic gravity gradient changes in a spherical symmetric Earth model: Application to the 2011 Tohoku-Oki earthquake. Journal of Geophysical Research: Solid Earth, 127, e2021JB023560.
