南北地震带中南段典型强震震前跨断层形变特征分析

摘要/Abstract

摘要： 基于南北地震带中南段18个不同震级的典型震例震前跨断层形变观测异常特征, 结合《中国震例》已有研究结果, 定性分析了各地震震前跨断层形变观测异常的类型和时、空变化特征。结果表明, 对于8.0级以下地震, 震前2~3年异常数量明显增多、震前1~1年半左右异常达到峰值、震前部分场地异常恢复的特征对区域强震预测在时间上具有一定的中期或短期前兆意义; 震前跨断层场地异常震中距和异常类型对强震震级具有一定的预测意义; 无论是跨断层异常类型、空间分布, 还是异常的时间进程特征均与区域强震发生地点没有显著的统计关系。汶川M_S8.0地震前出现趋势异常多、中短期异常较少、外围异常多和中心异常少的特征; 异常最早出现在7~8年前, 震前3年左右明显增加, 震前部分异常恢复; 异常以趋势异常和速度变化为主, 没有破年变异常。

关键词: 跨断层形变, 地震预测, 南北地震带中南段

Abstract: Based on abnormal characteristics of cross-fault observation in and around the mid-southern segment of the North-South Seismic Belts, and combined with the results from Earthquake cases in China, this paper qualitatively analyse temporal and spatial variation characteristics of cross-fault anormalies before typical earthquakes happened in the research zone. The results show that, for earthquakes less than M_S8.0, time variation characteristics that cross-fault anomaly increased obviously two to three years before earthquake happened, reached top value one year to a year and a half before earthquake occurred, and some anomalies disappeared before earthquake happened, may have relations to the prediction of the occurrence time of the large earthquakes which maybe happened in 1~2 years, or in several months; the epicentral distance and abnormal types of abnormal cross-fault observations are related to the prediction of the magnitude of the earthquake in the future; and all of the abnormal types, the spatial distribution characteristics and the time variations characteristics have no relationship with the place which the earthquake will happened in the future. For Wenchuan earthquake, it shows that there were more trend anomalies, little short term anomalies, more peripheral anomalies, and little in the center near the epicenter. The anomaly of Wenchuan earthquake first occurred about seven or eight years ago, and increased obviously about three years and some anomaly disappeared before the earthquake. The main types of these anomalies were trend and velocity variations, and there were no breaking yearly changes.

Key words: Cross-fault observation, Abnormal deformation characteristics, Earthquake prediction, Mid-southern segment of the north-south belt

中图分类号:

P315.7

陈长云, 郑智江, 李腊月, 畅柳. 南北地震带中南段典型强震震前跨断层形变特征分析[J]. 地震, 2016, 36(4): 47-60.

CHEN Chang-yun, ZHENG Zhi-jiang, LI La-yue, Chang Liu. Abnormal Characteristics of Cross-fault Observation in the Southern Segment of the North-South Seismic Belt[J]. EARTHQUAKE, 2016, 36(4): 47-60.

参考文献

[1] 薄万举, 郭良迁, 周伟. 据断层垂直形变确定华北活动块体边界[J]. 地壳形变与地震, 2001, 21(1): 64-71.
[2] 江在森, 祝意青, 王庆良, 等. 永登5.8级地震孕育发生过程中的断层形变与重力场动态图像特征[J]. 地震学报, 1998, 20(3): 264-271.
[3] 车兆宏, 范燕. 华北地区震前断层异常活动方式[J]. 地震, 2004, 24(2): 109-118.
[4] 李杰, 刘文义, 楼关寿, 等. 跨断层形变观测显示的断裂活动特征分析研究[J]. 中国地震, 2010, 26(1): 46-49.
[5] 张希, 唐红涛, 贾鹏, 等. 跨断层形变的慢时变结构分析与异常识别初探[J]. 武汉大学学报·信息科学版, 2013, 38(6): 710-715.
[6] 李忠华, 苏有锦, 刘祖荫. 丽江7.0级地震滇西实验场区跨断层短基线、短水准测量的变化特征[J]. 中国地震, 1998, 14(2): 140-149.
[7] 薄万举, 章思亚, 刘宗坚, 等. 大地形变资料用于地震预测的回顾与思考[J]. 地震, 2007, 27(4): 68-74.
[8] 江在森, 祝意青, 王庆良等. 永登5.8级地震孕育发生过程中的断层形变与重力场动态图像[J]. 地震学报, 1998, 20(3): 264-271.
[9] 王双绪, 江在森, 陈文胜, 等. 景泰5.9级地震的断层形变异常及中短期预报[J].地震学报, 2001, 23(2): 151-158.
[10] 苏琴, 杨永林, 郑兵, 等. 4·20芦山7.0级地震预测思路及过程回顾[J]. 地震地质, 2014, 36(4): 1077-1093.
[11] 陈兵, 江在森, 赵振才.中国西部断层形变趋势异常特征与地震活动关系研究[J]. 中国地震, 16(1): 77-85.
[12] 国家地震局震害防御司(编). 中国历史强震目录[M]. 北京: 地震出版社, 1995: 1-514.
[13] 中国地震局震害防御司(编). 中国近代强震目录[M]. 北京: 中国科学技术出版社, 1999: 1-637.
[14] CENC (China Earthquake Networks Center). http:∥www.csndmc.ac.cn/newweb/data.htm, 2015.
[15] 陈石, 徐伟民, 蒋长胜. 中国大陆西部重力场变化与强震危险关系[J]. 地震学报, 2015, 37(4): 562-574.
[16] Chen S, Jiang C S, Zhuang J C. Statistical evaluation of efficiency and possibility of earthquake predictions with gravity field variations and its analytic signal in western China[J]. Pure and Applied Geophysics, 2015, 1-15, doi:10.1007/s00024-015-1114x.
[17] 曹建玲, 李腊月. 华北地区跨断层前兆异常特征综述[J]. 地震, 2016, 36(4): 61-75.
[18] 李瑞莎, 张希, 唐红涛, 等. 青藏块体东北缘跨断层形变典型震例总结与预测判据指标分析[J]. 地震, 2016, 36(4): 35-46.
[19] 唐方头, 邓志辉, 张培震, 等. 由跨断层形变测量反映的华北地块近期断裂活动特征[J]. 中国地震, 2004, 20(4): 399-404.
[20] 中国地震局监测预报司. 汶川8.0级地震科学研究报告[M]. 北京: 地震出版社, 2009.
[21] 张肇诚主编. 中国震例(1976—1980)[M]. 北京: 地震出版社, 1990.
[22] 张肇诚主编. 中国震例(1981—1985)[M]. 北京: 地震出版社, 1990.
[23] 张肇诚主编. 中国震例(1986—1988)[M]. 北京: 地震出版社, 1999.
[24] 张肇诚主编. 中国震例(1989—1991)[M]. 北京: 地震出版社, 2000.
[25] 陈棋福主编. 中国震例(1992—1994)[M]. 北京: 地震出版社, 2002.
[26] 陈棋福主编. 中国震例(1995—1996)[M]. 北京: 地震出版社, 2002.
[27] 陈棋福主编. 中国震例(2000—2002)[M]. 北京: 地震出版社, 2008.
[28] 中国震例(2007—2012)[M]. 北京: 地震出版社, 待出版.
[29] 张希, 江在森, 王双绪, 等. 断层形变的应变强度比动态图像与震例综合研究[J]. 地壳形变与地震, 2001, 21(2): 37-42.
[30] 张希, 唐红涛, 李瑞莎, 等. 基于灰色关联度的鲜水河断裂活动特征与大震关系研究[J]. 地震研究, 2012, 35(4): 500-505.
[31] 周硕愚, 韩键, 宋永厚, 等. 断层网络形变前兆学原理与应用[J]. 地壳形变与地震, 1990, 10(1): 1-12.
[32] 薄万举, 华彩虹. 地形变强震前兆指标探讨[J]. 地震, 2001, 21(1): 25-32.