腾冲地震台观测井水位同震响应特征分析

Analysis of coseismic response characteristics of observation well water level at Tengchong Seismic Station

以2008—2017年腾冲地震台井水位记录的同震响应事件为研究对象,系统分析该井水位的同震响应特征,结合井孔地质背景条件,对同震响应机理进行初步探讨。结果表明:腾冲地震台井水位同震响应能力随着震级增大而逐渐增强;因井震距不同,同震响应主要表现为近震阶降—复原型和远震振荡型变化;同震响应幅度随震级增大而增大,随井震距增大而减小,且水位同震变化受震级与井震距的影响力基本相当;震级越大,同震响应持续时间越长;发生井水位同震响应的地震分布具有明显区位型特点。分析认为,振荡型同震响应机理与面波作用有关,阶降—复原型同震响应机理可能与腾冲地震台观测井所处地质构造有关。

This paper takes all coseismic response events recorded at the water level of Tengchong Seismic Station well from 2008 to 2017 as research objects,systematically analyzes the coseismic response characteristics of the well water level,and preliminarily discusses the coseismic response mechanism based on the geological background conditions of the well.The results show that the coseismic response ability of water level in Tengchong well increases with the increase of magnitude;Due to the different well spacing,the coseismic response patterns mainly show the variation of near earthquakes order falling-complex type and far earthquakes oscillation type;The coseismic response amplitude of well water level increases with the increase of magnitude and decreases with the increase of well seismic distance,and the ability of well water level variation affected by magnitude and seismic distance is basically equal;The larger the earthquake magnitude,the longer the coseismic response duration;Well water level coseismic response has obvious locational characteristics.The mechanism of coseismic response caused by distant earthquakes is related to surface wave action,and the mechanism of coseismic response caused by near earthquakes may be related to the geological and structural background conditions of the water level well at Tengchong Seismic Station.