深震前地下流体异常特征研究  

Research on anomalous characteristics in underground fluid before deep source earthquake

作　　者：李富[1] 李克[1] 刘俊清[1] 

机构地区：[1]吉林省地震局,吉林长春130022

出　　处：《地震》2005年第2期98-107,共10页Earthquake

摘　　要：论述了1999～2002年分别发生在吉林省汪清县、珲春县的二次深源地震前, 地下流体异常的形态、时间及空间演化特征. 研究结果认为, 其异常具有阶段性、配套性及集中性, 异常分布不均一、不连续, 与震中距、井震距密切相关. 异常的时空演化具有迁移性, 中、短期阶段异常由外围向震中方向迁移、收缩; 临震阶段, 异常由震中向外围发散. 并对深、浅源地震前地下流体异常的异同及异常机制进行了讨论, 认为单井的异常曲线、频带、变化速率、重复性及多井群体异常的空间分布是相同的, 而异常变化方向、幅度、形式、宏观现象、异常阶段和多井群体异常的时间特性、时空演化是不同的. 深震前地下流体异常是等效张应力、含水层孔隙压变化、水动力学三重机制共同作用的结果.In this paper the authors discussed the pattern, time and space evolutional characteristics before two deep source earthquakes, occurred in Wangqing and Hunchun County, Jilin Province. There are such features as phasic and assorted development and concentration, showing that the anomaly is distributed non-uniformly and discontinuously, and is closely related to the epicentral distance and the distance between the well and epicenter. Its time and space evolution is of migration feature, the short- and medium-term phasic anomaly migrated from the periphery to the epicentral direction and contracted. During the imminent stage the anomaly migrated from the epicenter to the periphery. The paper discussed the similarities and differences of underground fluid and anomaly mechanism before the deep source and shallow earthquakes. The authors conclude that the anomaly curve, frequency band, change rate and repeatedness of single well as well as anomaly time distribution of multiple well group are same, however, the direction, amplitude, pattern, macroscopic phenomenon and anomaly stage of single well are different from the time characteristics and time-space evolution of the multiple well group. The anomaly of underground fluid before the deep source earthquakes is resulted from joint action of three kinds of mechanism, i.e. equivalent extensional stress, change of pore pressure for aquifer and hydrodynamics.

关 键 词：深源地震 地下流体异常 时空演化 异常盲区 异常机制 时间特性 等效张应力 含水层孔隙压 水动力学 

分 类 号：P315.7[天文地球—地震学]