云南地区水位、水温对尼泊尔Ms8.1地震的响应特征研究

通过统计2015年4月25日尼泊尔MS8.1地震和5月12日MS7.5余震发生时云南地区水位、水温的空间分布、异常形态、变化幅度、起始和结束时间等远场响应特征,分析认为:同震响应主要集中在川滇菱形块体东南部、滇缅弧形块体东部和小滇西一带,即云南地区中西部;同井观测的水位、水温同震响应异常形态多样,单井同测项的同震响应异常形态具有一致性,与地震震级、震中距、方位无关;观测井的记震能力与观测仪器的分辨率、井孔含水层条件等有关,同震响应的异常幅度(ΔH、ΔT)与震级(M)、震中距(D)之间有一定的数量关系;近来云南区域地震活动整体呈现"平静—活动—平静"特征,小震活动有丛集特点,未来一段时间需注意滇西—滇西北和滇西南地区中强地震的危险性。

Co-seismic Response of Well Water Level and Temperature inYunnan Area to the Nepal MS 8.1 Earthquake in 2015

The co-seismic response of underground fluid wells to the 2015 Nepal M_S8.1earthquake and its aftershock M_S7.5 in the Yunnan area were recorded. Based on observed data, this paper analyzes the spatial distribution, anomaly shape, anomaly amplitude, and anomaly start and end times in the appropriate wells. The results show that the co-seismic responses were mainly concentrated in the southeast of the Sichuan-Yunnan rhombic block, the east of the Yunnan-Myanmar arc block, and the west of Yunnan area. The anomaly shapes of the co-seismic responses of water level and temperature in the same well are complicated and multiple. The observation items in a single well show consistency and are unconnected to earthquake magnitude, epicenter distance, and azimuth. The well''s ability to record earthquakes is connected to the resolution of the observation instrument, well aquifer condition, and so on. The co-seismic response anomaly amplitude shows a certain quantitative relationship with magnitude and epicenter distance. In recent years, seismic activity has shown a "quiet-active-quiet" characteristic and small earthquakes have been clustered in the Yunnan area. In the near future, there is a risk of moderate-strong earthquakes in the west-northwest and southwest of Yunnan.