汶川Mw7.9与日本Mw9.0地震同震电离层扰动研究

Coseismic Ionospheric Disturbances of Mw7.9 Wenchuan Earthquake and Mw9.0 Japan Earthquake

通过分析研究2008年的汶川Mw7.9地震、2011年的日本Mw9.0地震,发现伴随强震的发生,存在明显的同震电离层扰动现象。这种现象持续时间较短,一般在震前30～40min出现,并在震后大约10min达到极值,然后逐渐消失。持续时间及强度和震级存在着密切的关系,具体来说,震级越大其异常值也越大,持续时间也越长。另外一个值得注意的现象是,在震中附近出现较为明显的正异常的同时,距离震中较远的地区出现了负异常。

Coseismic ionospheric disturbances（CID）obviously exist when large earthquake oc- curs by analysis of Mw7.9 Wenchuan Earthquake and Mw9.0 Japan Earthquake. The dura- tion of CID is short, usually starts 30 -40 min before earthquake and reaches the extreme value about 10 min after earthquake. Then it disappears. The duration and amplitude of CID depends on seismic magnitude, specifically, magnitude greater and the duration and ampli- tude greater. In addition to clear precursory positive anomaly of ionospheric TEC around the earthquake epicenter, it＇s mentionable that weak negative anomaly of ionospheric TEC exist far away from the earthquake epicenter.