Premium
Formulation of coseismic changes in Earth rotation and low‐degree gravity field based on the spherical Earth dislocation theory
Author(s) -
Xu Changyi,
Sun Wenke,
Chao B. Fong
Publication year - 2014
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2014jb011328
Subject(s) - earth's rotation , geodesy , rotation (mathematics) , polar motion , geology , gravity of earth , gravitational field , dislocation , degree (music) , earth model , figure of the earth , magnitude (astronomy) , earth (classical element) , polar , geophysics , geometry , physics , mathematics , classical mechanics , condensed matter physics , astronomy , acoustics , mathematical physics
In this paper we present analytical formulas to compute the coseismic Earth rotation change (polar motion and length of day) and low‐degree gravity field change based on a spherical dislocation theory. Using the preliminary reference Earth model and our formulas, we calculate coseismic changes in Earth's rotation and low‐degree Stokes coefficients caused by the four largest earthquakes since 1960. The results verify that the present method is consistent with previous studies, but the method cannot be verified by the observations. A case study on the 2011 Tohoku‐Oki earthquake ( M w 9.0) indicates that the coseismic Earth rotation change depends on the magnitude and source parameters, and results show a difference between a point source and finite fault model. We also investigate the effect of seawater redistribution on coseismic Earth rotation change, but the effect is small and can be neglected.