On April 1 6,201 6,the Mw7.0 Kumamoto earthquake abruptly shocked in Ja-pan.In order to analyze the ionospheric variations in earthquake preparation area before the great earthquake,the GIM (global ionosphere map)supplied by the Center for Orbit Deter-mination in Europe and the observation data of gmsd and smst stations were utilized.Consid-ering the ionospheric disturbances caused by solar-terrestrial environment,the results indica-ted the total electron content decreased sharply in the 1 st day before Kumamoto earthquake, the amplitude was about-8 TECU.In addition,the distribution of global TEC anomalies showed obvious negative TEC anomalies appeared in the seismogenic zone,and most of TEC anomalies were distributed in the northern and southeast regions of Kumamoto earthquake, the duration of TEC anomalies was approximately 12 hours,which may be the ionospheric precursors of Kumamoto earthquake.%2016年4月16日日本熊本发生 Mw7.0地震,为了研究地震前孕震区的电离层异常。采用欧洲定轨中心提供的全球电离层图(GIM)与 gmsd、smst 测站的观测数据分析了孕震区的电离层变化情况。在排除了太阳与地磁活动造成的干扰之后,结果发现,在熊本地震前1天,孕震区内电离层电子含量显著下降,幅度达-8 TECU；同时全球 TEC 异常分布图显示,该天地震影响范围内有明显 TEC 负异常出现,异常主要出现在震中的北部和东南部区域,持续约12 h,这可能是熊本地震的电离层前兆之一。
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