闽南漳州沙建温泉区的微震观测

MICROSEISM OBSERVATION IN SHAJIAN THERMAL SPRING AREA OF ZHANGZHOU, SOUTHERN FUJIAN PROVINCE

1982年9—12月,在漳州温泉区布设了台网进行微震观测。结果表明,在漳州及其以北的沙建温泉区一带均有微震与小震群活动,震级为M_s=-1～1级,震源为3—14km。用震源的分布、震源机制解和微震综合断层面解的结果,研究了地质断裂的现今活动性及其与温泉的关系。认为区内东西向与北东向断裂是控制温泉分布的主要构造,而北西向断裂则是温泉的涌水构造。经探明,在有浅层热储的漳州市以及地质断裂发育的沙建地区,地震波速与介质泊松系数均低于正常值。此外,台网尚观测记录到一些异常的振动现象。根据地震的综合信息,探讨了研究区微震活动与水热活动的关系。

Microseismic surveillance network was set up to observe the microseismic activities in Shajian hot spring area of Zhangzhou from September to December, 1982. It is found that microseismic activities and microseismic swarms have been occurring frequently in the Shajian hot spring area. The seismic grade was at Ms -1~1 and the seismic source about 3-14km. According to the distribution of focus, the solution of focal mechanism and the result of explanation of fault plane, we have studied the relation between the current fault activities and thermal spring. We think that EW fault and NNE fault are the main structures which control the distribution of thermal springs. Meanwhile, NW fault is a struc- ture of pouring water. After exploration, it was found that the seismic velocity and medium Poisson coefficient are both lower than the normal values in Zhangzhou area which is with the shallow thermal reservoir and in Shajian area fault structure has been perfectly developed. In addition, some vibration anomaly also has been observed and recorded by the surveillance network. On the basis of these d ta, this article also gives a discussion on the relation between the microseismic activities and hydrothermal activities.