摘要
利用小波变换分析方法提取沂沭断裂带及其分支断裂跨断层流动短水准和长水准趋势变化成分,计算分析不同断裂的垂直形变速率和受力状态,结果表明:沂沭断裂带及其北西向分支断裂近期垂直形变速率均较小,没有明显的速率异常和受力状态改变;同一断裂具有分段和分时活动特征,断裂活动性质与地质考察结果基本一致;大部分水准观测场地在1995年苍山5.2级、2011年日本9.0级地震前后断裂垂直形变速率和受力方式发生了变化;山东近几年出现的跨断层水准异常基本结束,仅存的冯家坊子水准异常存在一定干扰,沂沭断裂带及附近地区近期发生强震的形变背景尚不明显。
Wavelet transform analysis method is utilized to extract the long-term trend component of both mobile short leveling and long leveling observations at the Yishu fault zone and its branch faults, and vertical deformation rate and stress state are calculated and analysed. The results show that： The vertical deformation rate of the Yishu fault zone and its NW branch faults are small, with no obvious abnormal rate and stress state change. The same fault may have piecewise and time-sharing activity characteristics, and fault activities are basically consistent with the geological investigation results. Vertical deformation rate and loading mode of most of the leveling observation fields changed before and after the Cangshan MS. 2 earthquak in 1995 and the Japan M9.0 earthquake in 2011. Several abnormal ohsvervations of across fault leveling in Shandong province in recent years main- ly have come to an end and there are some interference factors in the only remaining Fengjiafangzi leveling abnormity, so the crustal deformation background for a strong earthquake in the recent future is not obvious.
出处
《地震》
CSCD
北大核心
2018年第1期167-177,共11页
Earthquake
基金
中国地震局地震科技星火计划项目(XH16019)
2017年中国地震局监测运维项目资助
关键词
垂直形变
沂沭断裂带
小波变换分析方法
水准测量
Yishu Fault Zone
Vertical deformation
Wavelet transform analysis method
Leveling observation
