震源介质参数的连续监测及其在张北地震前的变化

地震 ›› 2000, Vol. 20 ›› Issue (z1): 154-161.

震源介质参数的连续监测及其在张北地震前的变化

张天中, 高阿甲, 黄蓉良, 刘庆芳

中国地震局地球物理研究所 ,北京 100081

收稿日期:2000-06-05 修回日期:2000-06-20 出版日期:2000-09-30 发布日期:2022-09-23
作者简介:张天中 (1945-) ,男 ,江苏苏州人 ,研究员 ,主要从事地震预测、地震波传播和工程地震等研究。
基金资助:
中国地震局“九五”科研攻关项目 (95-04-05-01)部分成果

Continuous monitoring of focal medium parameters and their changed before Zhangbei earthquake

ZHANG Tian-zhong, GAO A-jia, HUANG Rong-liang, LIU Qing-fang

Institute of Geophysics, CSB, Beijing 100081, China

Received:2000-06-05 Revised:2000-06-20 Online:2000-09-30 Published:2022-09-23

摘要/Abstract

摘要： 通过对首都圈地区的小震复合震源机制、尾波 Q值和波速比三项震源介质参数的连续监测发现 ,在 1998年 1月 10日河北张北 6. 2级地震前, 1997年小震复合机制解的矛盾符号比达到了历年的最低点 ,且其方向接近于张北地震由初动得到的震源机制方向; 山西恒山台 30~ 60 s时间窗的尾波 Q0 于 1997年出现了较高的值 ; 张北地区自 1995年 1月至 1997年 3月 ,存在 27个月的 V P /VS 的低值异常。这些结果除可直接作为前兆现象用于地震预测外 ,对于理解地震孕育发生的物理过程也是很有意义的。

关键词: 小震复合震源机制, 尾波 Q值, 波速比, 张北地震

Abstract: Continuously monitoring the compo site focal mechanism, coda Q and seismic wave velocity ratio, we have found that the inconsistency ratio of composite focal mechanism in 1997 reached its lowest value over the years and its direction similar to the Zhangbei earthquake. The coda Q0 for 30-60s-ti me window in 1997 is higher than before and the wave velocity ratio from February of 1995 to M arch of 1997 were lower than usual. These variations can be used as precursors to predict earthquake, also are helpful for us to understand the physical process of earthquake preparation and development.

Key words: Compo site focal mechanism, Coda Q value, Wave velocity ratio, Zhangbei earthquake

中图分类号:

P315.3

张天中, 高阿甲, 黄蓉良, 刘庆芳. 震源介质参数的连续监测及其在张北地震前的变化[J]. 地震, 2000, 20(z1): 154-161.

ZHANG Tian-zhong, GAO A-jia, HUANG Rong-liang, LIU Qing-fang. Continuous monitoring of focal medium parameters and their changed before Zhangbei earthquake[J]. EARTHQUAKE, 2000, 20(z1): 154-161.

参考文献

[1] 许忠淮, 阎明,赵仲和. 由多个小震推断的华北地区构造应力场的方向 [J]. 地震学报, 1983, 5(3): 268-279.
[2] 黄雨蕊,高阿甲,许忠淮 . 地震震源机制的研究应用于地震预报的探索 [J]. 地震地磁观测与研究, 1997, 18(1): 52-57.
[3] 华祥文 .唐山强震前后北京、天津周围地区应力的变化过程 [J], 地震学报, 1980, 2(2): 130-145.
[4] 阎明 .区域小震平均节面解的时空分析 [J]. 地震学报, 1991, 13(1): 10-20.
[5] Jin A, Aki K. Observational and physical bases for the co da Q-1 precursor [A]. In Evaluation of proposed earthquake precursors(ed M . Wyss) [C]. AG U, 1991, Washing ton, D C. 33-53.
[6] Cho et B, Aki K, Tsujiura M. Regional variation of the scaling law of earthquake source spectra [J]. Bull Seism Soc Am, 1978, 68: 49-79.
[7] Sa to H. Temporal changes in scattering and attenuation associated with the ear th quake o ccur rence— a review of recent studies on coda waves [J]. Pure Appl Geo pfy s, 1988, 126: 465-497.
[8] Jin A, Aki K.Temporal change in coda before the Tangshan earthquake of 1976 and the haichengearth quake of 1975[J]. J Geophy s Res, 1986, 91: 665-673.
[9] Novelo-Casanova D A, Berg E, Hsu V , et al . Time-space variation seismic S-wave coda attenuation(Q -1) and magnitude distribution (b-values) for the Petatlanea rthquake [J]. Geo phys Reslett, 1985, 12: 789-792.
[10] Peng J Y, Aki K, Lee W H K, et al . Temporal change in coda Qassociated with 1984 Ro und Valley earthquake in California [J]. J Geophys Res, 1987, 92: 3507-3536.
[11] Hellweg M, Spudich P, Fletcher J B, et al . Stability of co da Q in the region of Parkfield, California: View from the U . S. Geo logical Survey Parkfield Dense Seismograph Array [J]. J Geo phys Res, 1995, 100(B2): 2089-2102.
[12] Beroza G C, Cole A T, Ellsworth W L.Stability of coda wave attenuation during the Lo ma Prieta, California, earthquake sequence [J]. J Geo phy s Res, 1995, 100(B3): 3977-3987.
[13] 马云生, 张天中, 张焕生. 北京及其周围地区尾波 Q 值分布特征的研究 [J]. 地震学报, 1995, 17(4): 448-458.
[14] 王筱荣, 魏若萍. 用地震波参数预测地震的实践 [J]. 地震, 1997, 17(1): 75-79 .
[15] Gusev A A.Temporal variations of the co da decay rate on Kamchatka: Are they real and precursory? [J]. J Geophys Res, 1997, 102(B4): 8381-8396.
[16] Tselentis, G-Akis.Evidence for stability in coda Q associated with the Egion (Central Greece) earthquake of 15 June 1995[J]. Bull Sism So c Am, 1997, 87(6): 1679-1684.
[17] 马云生, 黄蓉良, 张天中, 等 . 华北地区尾波 Q值分布特征及其准实时监测 [J]. 地震地磁观测与研究, 1998, 19(1A): 62-66.
[18] 李清林, 张文玉. 张北6. 2级地震及晋北地区的重力场变化 [A]. 中国地震学会 . 第七次学术大会论
文摘要集[C]. 北京: 地震出版社, 1998. 106 .
[19] 力武常次 . 地震预报[M]. 冯锐, 周新华译. 北京: 地震出版社, 1978. 123-128.
[20] Wyss M.Second round of evaluations of proposed earthquake precusors [J]. P A GEO PH, 1997, 149: 3-16.