Han Shin-Chan, Shum C K, Bevis Michael, Ji Chen, Kuo Chung-Yen
Geodetic Science, Department of Geological Sciences, Ohio State University, 275 Mendenhall Laboratory, 125 South Oval Mall, Columbus, OH 43210-1398, USA.
Science. 2006 Aug 4;313(5787):658-62. doi: 10.1126/science.1128661.
We report the detection of an earthquake by a space-based measurement. The Gravity Recovery and Climate Experiment (GRACE) satellites observed a +/-15-microgalileo gravity change induced by the great December 2004 Sumatra-Andaman earthquake. Coseismic deformation produces sudden changes in the gravity field by vertical displacement of Earth's layered density structure and by changing the densities of the crust and mantle. GRACE's sensitivity to the long spatial wavelength of gravity changes resulted in roughly equal contributions of vertical displacement and dilatation effects in the gravity measurements. The GRACE observations provide evidence of crustal dilatation resulting from an undersea earthquake.
我们报告了通过天基测量检测到一次地震。重力恢复与气候实验（GRACE）卫星观测到2004年12月苏门答腊 - 安达曼大地震引发的重力变化为±15微伽。同震变形通过地球分层密度结构的垂直位移以及改变地壳和地幔的密度，在重力场中产生突然变化。GRACE对重力变化的长空间波长的敏感性导致在重力测量中垂直位移和膨胀效应的贡献大致相等。GRACE的观测结果为海底地震导致地壳膨胀提供了证据。
