三峡井网地下流体动态与映震能力的初步分析  

BEHAVIORS OF SUBSURFACE FLUID AND THEIR RESPONSIBILITY TO SEISMIC EVENT IN THREE-GORGE OBSERVATION WELL NETWORK

作　　者：刘五洲[1] 鱼金子[1] 车用太[1] 刘喜兰[2] 姚运生[3] 颜萍[3] 

机构地区：[1]中国地震局地质研究所,北京100029 [2]天津市地震局,天津300201 [3]中国地震局地震研究所,武汉430071

出　　处：《地震地质》2003年第4期632-639,共8页Seismology and Geology

基　　金：中国地震局地质研究所论著2003B0040。

摘　　要：系统分析了三峡井网 8口井水位、4口井水温和 4个井台土氡 2 0 0 1年的观测数据 ,建立了各个测项的正常动态 ,并检验了其各自的映震能力。结果表明 ,8口井水位均有固体潮显示 ,其对地壳体应变的响应灵敏度为 10 - 9～ 10 - 10 体应变 /mm。井水位大多有气压效应 ,并受一定程度的降雨干扰。 4口井的水温动态相对平稳 ,日变幅一般为千分之几度。 4个井台的土氡动态起伏较大 ,变化范围在几到几十Bq/L之间。在 2 0 0 1年 10月 16日秭归县梅家河ML3 6地震前 ,有 6口井水位、1口井水温和 1个井台的土氡有异常显示 ,表明三峡井网具有较强的映震能力。This paper presents the results of analysis of observed data of water levels from 8 observation wells, water temperature from 4 wells and soil radon from 4 well sites obtained during the year of 2001. Based on the work, the normal behaviors of each observation item are established and their responsibility to earthquake event are tested. The results indicate that all the groundwater levels from 8 wells are able to reflect the solid tide. The sensitivity of the response of groundwater to volumetric strain of the earth crust in eight wells ranges from 10 -9 to 10 -10 volumetric strain/mm. Groundwater levels in most wells within the well network have barometric effects and are influenced to some extent by the rainfall. The water temperature in 4 wells is relatively stable, the daily change of which is ranging within several degrees a thousandth. The soil radon in 4 well sites fluctuates dramatically, and the annual change ranges from ten to several tens Bq/L. The anomalies of water levels in 6 wells, water temperature in one well, and soil radon in one well site were observed before the M L3.6 earthquake occurred at Meijiahe, Zigui County on October 16, 2001. This may indicate that the Three Gorge observation well network has a relatively high capability to respond earthquake event.

关 键 词：地下流体 映震 正常动态 震前异常 三峡井网 

分 类 号：P315.723[天文地球—地震学]