日本Ms9.0地震前的连续重力观测异常

GRAVITY ANOMALIES IN BEFORE Ms9.0 EARTHQUAKE IN JAPAN OBSERVED BY CONTINUOUS RELATIVE GRAVIMETER IN CHINA

日本Ms9.0地震后,检测了17台(套)gPhone重力仪和成都GS15连续重力观测仪震前3天的观测数据。发现:乌什、郑州台的gPhone重力仪和成都台的GS15重力仪分钟采样在震前3天出现了不明原因的高频异常现象。初步分析表明,成都、乌什在3月9日的日本Ms7.3地震前的16小时产生了纺锤状的隆起现象;郑州台在日本Ms7.3和Ms9.0地震震前出现了明显的柱状异常现象。其异常虽然可以排除热带气旋、人为干扰等因素的影响,但与日本地震的关系以及震前更长时间尺度的异常还有待进一步分析。

After Ms9.0 earthquake in Japan,the data of 17 gPhones and GS15 continuous relative gravimeters 3 days before the huge earthquake were analyzed.It is shown that there were some unknown gravity anomalies of gPhone and GS15 in Wushi,Zhengzhou and Chengdu station.The preliminay analysis shows that the records at Chengdu and Wushi stations had the type of spindle gravity disturbance 16 hours before the Ms7.3 earthquake of Japan in 2011-03-09.And the gravimeter’s records in Zhengzhou station had the cylindrical gravity disturbance not only before the Ms7.3 earquake but also the Ms9.0 earquake in Japan.Although the tropical cyclones,the impact of human disturbance and other factor can be ruled out,the relationship between the gravity disturbance and the earthquake in Japan and the data of even more time scale are remained to be further analyzed.