大姚6级双震前的地震前兆特征  

CHARACTERISTICS OF EARTHQUAKE PRECURSOR BEFORE TWO DAYAO EARTHQUAKES

作　　者：张燕[1] 吴云[1] 刘永启[2] 施顺英[1] 

机构地区：[1]中国地震局地壳应力研究所武汉创新基地 [2]武汉大学,武汉430079

出　　处：《大地测量与地球动力学》2004年第4期72-75,共4页Journal of Geodesy and Geodynamics

基　　金：地震科学联合基金 (60 40 2 1)

摘　　要：在连续形变观测资料中除了存在于整个时间域的短周期潮汐信息 (固体潮 )外 ,还有出现在某个时间段的长周期非潮汐信息 ,如何从时间或空间上认识和提取这些信息 ,成为认识地震过程和进行地震预报关键和迫切的问题之一。利用小波分析的时 频特性和奇异性检测特性 ,对大姚 6级双震前的连续形变观测资料进行了处理 ,提取潮汐资料中的非潮汐信息。发现在地震前震中附近的形变台站都接收到了相同频段的异常信号 ,周期为几天到十几天 ,出现在各个台站的时间也大致相同。这些在震前具有一定时、空分布的信息有可能是地震前兆。Continuous deformation data include short-period tidal information which exists in the whole time domain and long-period non-tidal information which exists in some time phases. How to identify and obtain time and space distribution of the information is very important to know about the seismic process and serve for earthquake prediction. In this paper,wavelet analysis is introduced into the continuous deformation data processing. The study shows that before two Dayao earthquakes the deformation stations near epicenter recorded some abnormal signals of the same frequency at the same time and their period is from several days to over ten days. These abnormal signals with certain time-space distribution are earthquake precursor possibly.

关 键 词：形变观测 地震前兆 潮汐 台站 前震 形变台 固体潮 空分 定时 信息 

分 类 号：P315[天文地球—地震学] P414.95[天文地球—固体地球物理学]