The Use of Satellite Gravimetry: Coseismic Gravity Changes in Central Chile, Sumatra-Andaman and the Earthquake in Tohoku - Oki
Speaker: Yu-Siang Lin
Abstract
The GRACE (Gravity Recovery and Climate Experiment) space mission, launched in March 2002, consists of two low-orbiting spacecrafts linked by an inter-satellite microwave ranging system. Besides, GRACE has first detected coseismic gravity changeable in Sumatra-Andaman earthquake (Mw 9.0 - 9.3) in 2004. The earthquake in central Chile also left coseismic gravity changeable detectable by GRACE in 2010. The Tohoku-Oki earthquake in 2011 is the third detection by GRACE of coseismic gravity changeable. In addition, the spatial patterns of the gravity changeable of these earthquakes are very similar because they are all shallow angle reverse faulting at convergent plate boundaries. We compared seismic moments and maximum gravity decreases observed by GRACE. Also, we found the linear relationship between decrease in gravity and seismic moments. It appears that the gravity approximately changes scales with the moment, and the threshold of their detection with GRACE seems to lie in Mw 8.6 - 8.7.
Reference
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