| 多种地球物理场观测数据中亚失稳现象 |
| |
| 引用本文： | 张淑亮,王霞,郭文峰,陈慧,李惠玲.多种地球物理场观测数据中亚失稳现象[J].吉林大学学报(地球科学版),2021,51(2):571-583. |
| |
| 作者姓名： | 张淑亮 王霞 郭文峰 陈慧 李惠玲 |
| |
| 作者单位： | 1. 山西省地震局, 太原 030021;2. 太原大陆裂谷动力学国家野外科学观测研究站, 太原 030025 |
| |
| 基金项目： | 山西省地震局科技攻关项目(SBK-1936);山西省重点研发计划项目(201903D321013)。 |
| |
| 摘 要： | 20100124山西河津M4.8地震前，临汾地震台宽频倾斜仪记录到与实验室岩石破裂亚失稳过程类似图像，震源及附近地区也出现多项准同步性的短临异常。本文对这次地震前震源及附近地区多种地球物理场观测数据在发震断层黏滑失稳前不同阶段的变化特征进行了探讨。结果表明：1）震前记录到的亚失稳现象并非单点单测项，而是具有多点多物理场的群体性特征；2）这些异常出现的时间与临汾宽频倾斜仪记录的亚失稳事件时间基本同步，其形态上以大幅突变为主，时间上多集中在震前45 d左右，空间上主要集中在距震中100 km的范围内，且具有随时间从外围向震中区集中的特点；3）震前不仅在多种地球物理场观测数据中记录到类似亚失稳现象，而且在震前1~6 d一些地球物理场观测仪器还记录到与发震断层失稳前预滑有关的小事件；4）震前临汾宽频倾斜仪记录到的亚失稳现象、震源及附近地区出现多项准同步性的短临异常，是在震源及附近地区的区域应力场增强、介质特性发生改变的情况下出现的，可能与河津地震有关；5）震前多种地球物理场异常随时间推移显示出协同化的特点，即沿发震断裂方向有由外围向震中迁移和集中的特点。
|
| 关 键 词： | 河津M4.8地震 地球物理场 亚失稳 区域应力 |
| 收稿时间： | 2020-02-18 |
Sub-Instability Phenomena in Various Geophysical Fields Observation Data |
| |
| Zhang Shuliang,Wang Xia,Guo Wenfeng,Chen Hui,Li Huiling.Sub-Instability Phenomena in Various Geophysical Fields Observation Data[J].Journal of Jilin Unviersity:Earth Science Edition,2021,51(2):571-583. |
| |
| Authors: | Zhang Shuliang Wang Xia Guo Wenfeng Chen Hui Li Huiling |
| |
| Institution: | 1. Shanxi Earthquake Agency, Taiyuan 030021, China;2. National Continental Rift Valley Dynamics Observatory of Taiyuan, Taiyuan 030025, China |
| |
| Abstract: | Before the M4.8 earthquake on January 24, 2010 in Hejin, Shanxi, the broadband inclinometer at the Linfen seismic station recorded the images that are similar to the sub-instability process of rock fracture, and a number of quasi-synchronous short-term and imminent anomalies were also captured in the laboratory in the epicenter and nearby areas. In this paper, the change characteristics of different geophysical fields observation data before the Hejin M4.8 earthquake and the changes in different stages before stick-slip instability of the seismogenic fault are discussed as follows: 1) The sub-instability phenomenon recorded before the earthquake is not a single point or single measurement event but multi-points and multi-physical fields characteristics;2) The occurrence time of these anomalies is basically synchronous with the time of the sub-instability events recorded by the Linfen broadband inclinometer, and their morphology is mainly characterized by large sudden changes, mostly concentrated in the period of about 45 days before the earthquake within 100 km from the epicenter, and with time passed, they become frequent from the periphery to the epicenter area;3) Before the Hejin M4.8 earthquake, not only were similar sub-instability phenomena recorded in various geophysical field observation data, but also some small events related to pre-slip were captured by some precursory observation instruments before the instability of the seismogenic fault 1-6 d before the earthquake;4) The sub-instability phenomenon recorded by the Linfen broadband tilt-meter before the Hejin M4.8 earthquake, and the amount of quasi-synchronous short-term and imminent anomalies in the epicenter and nearby areas occurred when the regional stress in the source and nearby areas increased and the medium characteristics changed;5) The various geophysical field anomalies before the Hejin M4.8 earthquake showed the coordination of migration and concentration from the periphery to the epicenter along the direction of the seismogenic fault over time, which should be related to the Hejin earthquake. |
| |
| Keywords: | Hejin M4 8 earthquake geophysical fields meta-instability regional stress |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《吉林大学学报(地球科学版)》浏览原始摘要信息 |
| 点击此处可从《吉林大学学报(地球科学版)》下载免费的PDF全文 |
|
