天山地震带及乌恰交汇区强震活动特征

STRONG SEISMIC ACTIVITIES IN TIANSHAN SEISMIC ZONE AND WUQIA CONVERGENT AREA ANALYSIS

根据1880～1990年天山和乌恰地区M_s≥5.5级地震资料,分析讨论了研究区内各带强震活动的韵律特征和相关性、强震活动的整体迁移规律及环境因子与强震之间可能存在的某些内在联系。用信息熵和马尔柯夫方法对各地震带资料进行了统计计算。认为:在大区域构造应力场作用下,由于力源和构造环境的差异,造成区内应力场分布不均匀,应力在一定范围内变化、调整和传递,形成了各带地震活动在时间和空间分布上的差异。据此对整个天山地震带和乌恰区近期强震活动趋势作了判断。

Some internal relations of strong seismic activities with rhythmic feature, simularity, bulk migration regulation and environment factors were analyzed and discussed according to the seismic data (Ms = 5. 5)in Tianshan and Wuqia areas during 1880-1990. After statistically calculating the seismic data of each zone by means of information entropy and and Markov method.it is considered that under the force of large regional tectonic stress field,nonuniform stress field was formed due to the difference of tectonic environment and force source. As stress varied, adjusted and transfered in a certain range,difference of seismicity on each zone appeared in the aspects of time and space. Recent tendency of seismic activity in the whole region of Tianshan seismic zone and Wuqia area was considered based on the above facts.