摘要
分析2016年10月20日射阳M_S4.4地震前地下流体典型异常特征并对其机理进行讨论。该地震前的地下流体前兆异常(1)从时间进程看可分为中期趋势背景异常和短期异常;(2)从空间演化上看,在中期趋势背景阶段,异常分布在离震中300km范围内,其在起始时间上表现为从震中向外围迁移继而向震中靠拢的特点。相较于中期趋势背景阶段异常;短期异常在空间上向震中收缩,分布在离震中100~200km范围内,其在起始时间上,表现为向震中靠拢的特点。井水温异常变化可能是区域应力加载作用的产物,而离子浓度的变化可能是水岩反应加剧引起的。
In this paper,we summarize the characteristics of the typical underground fluid anomalies associated with the Sheyang M_S4.4 earthquake that occurred on Oct.20,2016,and discuss the precursor mechanisms.Our analysis results show that the underground fluid anomalies prior to the earthquake can be divided into medium-and short-term anomalies.The medium-term anomalies are distributed within a 300-km radius of the epicenter and initially migrated from the epicenter to the outer area and then near to the epicenter.Compared to the medium-term anomalies,the short-term anomalies are located much closer to the epicenter,being distributed within 100-200 km of the epicenter and migrate close to the epicenter.The spatial properties and distribution characteristics of the anomalies show that the change in the water-temperature anomalies,which occurred prior to the Sheyang earthquake,may be caused by regional stress variations.
出处
《地震工程学报》
CSCD
北大核心
2017年第A01期72-78,共7页
China Earthquake Engineering Journal
基金
地震监测预报专项(1770505)
地震动力学国家重点实验室开放基金课题(LED2013B04)
关键词
射阳MS4.4地震
地下流体
典型前兆异常
Sheyang M_S4
4earthquake
underground fluid
typical precursory anomalies
