The Sumatran earthquake impact on Earth Rotation from satellite gravimetric measurements

Christian Bizouard (1) , Lucia Seoane (1)

1 SYRTE - Systèmes de Référence Temps Espace

From the satellite gravity field measurements (mission GRACE and LAGEOS) we computed the changes in inertia moments of the Earth, which have followed the gigantic Sumatra Earthquake of December 26, 2004. Our approach is based upon the geoid height variations, which has been caused by the Earthquake. According to those gravimetric data, the pole was shifted up to 2 mas towards 90 degree East and the length of day dropped up to -5 microseconds. The phase obtained for the pole shift contradicts that one derived from seismic model.

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]

Christian Bizouard, Lucia Seoane. The Sumatran earthquake impact on Earth Rotation from satellite gravimetric measurements. 2006. ⟨hal-00117348⟩