1976年唐山地震前后的重力变化和震区莫霍面的变形
GRAVITY VARIATION AND MOHO SURFACE DEFORMATION BEFORE AND AFTER 1976 TANGSHAN EARTHQUAKE
-
摘要: 本文分析了1976年唐山地震前后十年的流动重力测量资料及其观测精度,通过降噪试验和可靠性分析,证实了重力趋势性异常变化的存在;分析了引起重力变化的物理因素,采用时域带通滤波的方法对资料进行预处理,用样条函数求得了重力测值的拟合曲面和分析区域等间距网点异常变化值,借助于窗口滑动求均方法滤去浅部短波长密度扰动的重力效应,根据剩余重力异常场作约束反演,发现震前、震时和震后该区莫霍面附近岩层可能出现过变形,尤其是震前数年,变形幅度可能更大。看来,莫霍面附近岩层的变形可能是造成壳内应力集中并孕育唐山地震的重要原因。Abstract: In this paper, data of mobile gravity survey and the observation precision within ten years before and after the 1976 Tangshan earthquake were investigated. It was proved that there existed a trend of anomalous change in the epicentral region before and after the earthquake through the noise-depression experiment and reliability analysis. We analysed the physical factors which caused the gravity variation. Bandpass filtering method in the time domain was adopted to preprocess the data. A fitting curved surface to the values of gravity survey was obtained. We also analysed the values of anomalous change at equally spaced points in the region with the aid of the moving window average method to filter out the gravitational effect caused by shallow short wavelength density changes. Restraint inversion was done according to the remainder of the abnormal gravity field and it was found that deformation in rock formation in the vicinity of the Moho surface in this area might have appeared before, during and after the earthquake; especially, the deformation amplitude might be rather large several years proior to the earthquake. It is shown that the deformation of the rock formation near tie Moho surface may be a significant cause of stress concentration in the crust and the seismogenesis of the Tangshan earthquake.
-
-
[1] 国家地展局编辑组,一九七六年唐山地震,地震出版社,1982.
[2] Gu Gongxu, On the variation, of gravity field before and after large earthquakes, ISCSEP Abstracts,The Organizing Cpmmittee of ISCSEP, 1982.
[3] 陈运泰、顾浩鼎、卢造勋,1975年海城地震与1976年唐山地震前后的重力变化,地震学报,2, 1, 1980.
[4] 赵炜、马丽,重力重复测量精度讨论,地壳形变与地震, 3, 1981.
[5] 贾民育、袁果田、项爱民、齐敏,唐山地震前后的重力场及其与地壳垂直形变的关系,地壳形变与地震,创刊号,1981.
[6] Ma Li and Zhao Wei, Gravity variation before and after the Tangshan earthquake, Tectonophysics, 97,p. 158, 1983.
[7] 阿姆斯塔特,B. L. 可靠性数学,彭兴文译,科学出版社,1978.
[8] Weiss, M. R. et al., Study and development of the INTEL. technique for improvement of speech intelligibility, NTIS, 1975.
[9] 邢如英、田时秀、孔繁永、何承奎,二阶谱法及其在地声数据处理上的应用,地震料学研究,6, 1984.
[10] 高木昇等,可靠性摹础数学,五所译,国防工业出版社,1979.
[11] 吴兵,唐山地震的重力异常,西北地震学报,3, 3, 1981.
[12] 朱岳清,一个三维密度界面反演的权函数法,地震科学研究,1, 1984.
[13] 滕吉文、姚虹、周海南,北享、天津、唐山和张家口地区的地壳结构,地球物理学报,22, 3, 1979.
[14] 邵学钟、张家茹、章思亚、李振江,京津唐地区地壳上地幔立体构造,地震地质,4, 1, 1982.
[15] 张少泉、林楚贞、安昌强,北京地区莫霍界面形状的初步研究,地震学报,3,4, 1981.
[16] 刘元龙、王谦身、赵建华,根据重力资料探讨北京一天津及其邻近地区的地壳构造,地球物理学报,21,1,1978. -
期刊类型引用(5)
1. 王玮铭，冯志生，朱培育，廖晓峰，何畅，张致伟. 2021年9月16日四川泸县M_S6.0地震前地磁扰动异常特征分析. 地震工程学报. 2025(01): 229-239 . 
百度学术
2. 索朗南杰，桑杰卓玛，索朗多吉，次仁多吉，益西拉姆，高锦瑞. 2008年以来西藏地区强震前固体潮调制比特征分析. 地震地磁观测与研究. 2023(01): 14-22 . 百度学术
3. 艾萨·伊斯马伊力，翟世龙，张桉赫，冯丽丽，贺曼秋，冯志生. 新疆地区电磁预测指标体系在2023年1月30日沙雅M_S6.1地震中的应用. 内陆地震. 2023(03): 272-280 . 百度学术
4. 李霞，冯丽丽，赵玉红，张朋涛，刘磊，苟智栋. 2021年青海玛多M_S 7.4地震前电磁异常时空演化特征. 地震地磁观测与研究. 2023(S1): 229-233 . 百度学术
5. 冯丽丽，李霞，赵玉红，张朋涛. 2022年1月8日青海门源6.9级地震短临异常跟踪分析. 中国地震. 2022(01): 12-20 . 百度学术
其他类型引用(2)
计量
- 文章访问数: 1068
- HTML全文浏览量: 28
- PDF下载量: 40
- 被引次数: 7
下载:
