摘要
本文使用滇西地震实验场区近场微震观测中的洱源、脉地、松挂地区的三次微震序列资料，研究了地面运动峰值速度ｖｍ与地震矩Ｍ０和环境应力τ０的关系，利用ｖｍ∝Ｍ０１／３τ０４／３的关系，估算了这三次微震序列的环境应力参数τ０值和应力降△σ。结果认为，地面运动峰值速度参数（ｖ·ｒ）是环境应力参数τ０或△σ的函数，且τ０或△σ与地震构造背景及介质状态相关，表现为处于不同构造背景的三次微震群测定的τ０和△σ值存在明显的差异。脉地震群为高应力序列，应力参数在（０．５～５．０）ＭＰａ，松桂震群为中等应力序列，在（０．３～１．５）ＭＰａ；洱源震群为低应力序列，在（０．０１～０．５）ＭＰａ。由此而讨论了不同构造背景与环境应力参数的依赖性及其前兆意义。
In this paper, using digital data of 3 earthquake sequencies observed from near field in Eryuan, Maidi and Songgui located in WYEPSA,we have studied the relationship among peak velocity of ground motion Vm,seismic moment Mo and surrounding stress τo. The surrounding stress value τo and stress drop △σ of the 3 earthquake sequencies have been evaluated from the relations of Vm∝M01/3 τ04/3. The results show that the peak velocity of ground motion, v and r, are the functions of surrounding stress τo and △σ, which are related with seismic structural background and media state that demonstrate obvious differences of τo and △σ in 3 micro-seismic swarms located in different structures. Maidi swarms show high stress sequence with stress parameter 0.5-5.0 Mpa,moderate stress sequence with 0.3-1.5 Mpa for Songgui swarms and low sequence with 0.01-0.5 Mpa for Eryuan swarms. From mentioned above,dependence and precursory sense between different structures and surrounding stresses have been discussed in this paper.
出处
《地震研究》
CSCD
北大核心
1995年第4期341-349,共9页
Journal of Seismological Research
基金
国家地震局"八五"重点资助
关键词
地面运动
地震构造
微震
地面运动
环境应力值
Ground motion
Stress
Seismotectonics
Microearthquake
Western-Yunnan Earthquake Prediction Study Area
