[M-IS03] Interdisciplinary studies on pre-earthquake processes

[MIS03-P03] Possible geomagnetic Sq abnormal related to great earthquake

*Xiaocan Liu^1,2、Katsumi Hattori^2,3、Peng Han⁴ (1.Institute of geophysics China Earthquake Administrition、2.Graduate School of Science, Chiba University, Chiba, Japan、3. Center for Environmental Remote Sensing, Chiba University, Chiba, Japan、4.Department of Earth and Space Sciences, Southern University of Science and Technology, ShenZhen, China)

キーワード：geomagnetic Sq, abnormal, great earthquake

At about 130°E to 150°E longitude sector, using 20 geomagnetic observatories absolute minutely xyz- three components data from 2009 to 2012, we detect the possible abnormal of geomagnetic solar quiet variation (Sq) related to the great Tohoku Mw9.0 earthquake, shocked at 11th Mar.2011, firstly, by NOC analyzing we pick out Sq variation from observation, then by Spheric Harmonic Analyzing (SHA), we depart the inner and external equivalent currents Je and Ji, well as the two parts model geomagnetic field Be and Bi, as the results, Je and Ji, well as the deviations ΔJe and ΔJi, are distorted in epicenter area at two geomagnetic quiet days of 27th and 23th in Jan. 2011, namely two months before the earthquake, and the x components phase direction changed for MMB ESA KNY OKI stations, besides the enlarged magnitudes at the two quiet days (23th and 27th), especially the different pattern of OKI at 27th, as double maximum of pre-noon and after-noon variation appeared.