大規模地震発生時の電離圏総電子数の変動解析

抄録

This paper describes an analysis of trend changes of the total electron content (TEC) on the ionosphere as a possible precursor to massive earthquakes from 2005 to 2012 around Japan. To evaluate the TEC, we defined an index called Ratio, which can measure the deviation of a trend line of TEC around the target period. Regarding the earthquakes whose magnitude was more than 5, the results confirmed that the value of Ratio tended to be affected especially when the depth of earthquake occurrence points was less than 100 km.