Abstract
The Earth’s spin axis moves by various factors, and mass redistribution associated with seismic faulting is also expected to contribute to this movement. However, there have been no space geodetic observations of coseismic polar motion excitations to date. In this study, we analyze the time series of the excitation functions of the polar motion, and try to detect steps due to the three recent M9 class earthquakes, i.e. the 2004 Sumatra-Andaman, the 2010 Chile （Maule）, and the 2011 Tohoku-Oki earthquakes. For the 2010 Chile earthquake, a significant step was detected but was not consistent with the anticipated direction.
