【摘要】 基于法国DEMETER卫星数据,在识别2级图像的基础上,通过对1级数据进行滑动中值处理、纬度变化分析以及空间差值研究,发现2010年2月27日智利8.8级地震的震前震中区上空附近有异常变化:20日距离震中1500 km处电子浓度升高,24日电子浓度降低;25、26日电场、磁场及部分等离子体参量呈现同步扰动;26日2条轨道的电子浓度值出现高于背景值的异常;27日震前4小时在磁赤道附近出现电场频谱下降,等离子体参量强烈扰动的现象.更多还原

【Abstract】 Based on the data of France DEMETER（Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions） satellite,some abnormities in the ionosphere above the epicenter of February 27^th,2010,Chile M8.8 earthquake were found through distinguishing level 2 picture and analyzing level 1 data with moving median,latitude study,and spatial difference methods.In the area 1500 km apart from the epicenter,electron density rose on Feb 20^th. Electron density declined on 24^th.Electric,magnetic fields and some plasma parameters disturbed at the same time on 25^th and 26^th.Besides that,on 26^th,electron density of 2 orbits exceeded the background values.Electric field spectrum around magnetic equator on 27^th began to drop 4 hours before the earthquake,and there were simultaneous strong perturbations of some plasma parameters.更多还原