1999年11月大同地震部分余震的定位及震源机制反演
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摘要
本篇硕士学位论文通过对1999年11月1日大同-阳高5.6级地震的部分余震序列的精确定位和震源机制解的测定,分析了大同地震部分余震和区域应力场的分布情况。精确定位结果显示此次余震活动分布于近东西走向的六棱山北麓断裂和北东走向的大王隐伏断裂及北西走向的团堡断裂交汇带上,地理位置在六棱山东段的秋林村至大王村段约10公里处。震源机制解的结果表明此部分余震的运动形态主要为正倾滑断层。但是各个余震所在的断层走向并不完全一致,余震的震源机制解反映了处于多个断层交汇处的复杂的构造应力状态。
第一章 介绍了对数字地震台网记录的1991年11月1日大同-阳高5.6级主震后的部分余震系列的精确定位过程。
中国地震局地球物理所的王鸣和腾云田等在1999年11月1日大同5.6级地震发生后,在主震的震中区附近用数字地震仪对余震进行了近场观测。我们整理了1999年11月7日至11月18日的观测记录资料,利用SHM地震分析处理软件对余震系列的震相到时进行了拣取,根据山西地质条件和王培德等的地层速度模型建立了速度模型,用可以调整模型参数的定位程序HYPO71对此部分余震系列进行了定位计算。将定位结果绘制于大同-阳高极震区附近构造图上,显示这部分余震主要分布在近东西走向的六棱山山前断裂带、北西西走向的团堡断裂和北东北方向的大王断裂的交汇带上。与地质调查提供的断层活动资料比较,大同余震基本上是位于大王到秋林这一段处于地质上的最活动断裂带上。
第二章 描述了为余震记录中波形数据记录清晰完整的18个余震,测定其震源机制解的过程和结果。采用水平分层介质中计算理论地震图方法,通过调整大王、后贵仁和堡村三个台站的沉积层的厚度模型使得计算理论地震图所得到直达波Sg-Pg的走时差与实际记录波形的Sg—Pg的走时差一致。转换原始的加速度记
This article is for a master degree. An earthquake with magnitude Ms 5.6 hit the place from Pucun village to XituanPu village, Datong county, Shanxi province in the first of November, 1999. An aftershock sequence followed the main event. The location and mechanism of partial aftershocks were illustrated in this paper. We located 31 events, which are well recorded, and 18 of them, which have clear waveform, were chosen to calculate the mechanism. We use the software "Seismic Handler" and HYP071 program for location. And we use the moment tensor inversion program to calculated focal mechanism. The process of moment tensor inversion is in frequency domain. The location result shows that the aftershock sequence is at an intercourse of EW striking Liulengshang fault, the NE striking Dawang fault and NW striking TuanBao fault. The mechanism shows that the movement of aftershock is on strike-slip fault. But the strikes of different events are not at same orientation. This is why the location was in the fault intercourse place.Chapter one describes the location process. Staff of the institute of geophysics set up a temporal digital seismic network around the meizoseismal region after the magnitude 5.6 earthquake of November 1st, 1999. We sort out the record of the aftershock sequence began from the eleventh of November to eighteenth, using the software of "Seismic Handler" for phase time picking and HYPO71 program for calculating the hypocenter location. We get the velocity model by refence from "rupture activities of Datong in Oct., 1989 and Mar., 1991" ( Wang and Stammler, 2001., in Chinese). The epicenter distribution map shows that the location of aftershock is fit for the activity of faults locating in Datong, Shanxi area.Chapter two describes the way to use the moment tensor inversion program to calculating the focal mechanism of 18 events, which have clear waveform among the well located 31 events. The resolution of mechanism shows that the movement of aftershock event is on strike-slip fault. But the strikes are not at same orientation. This is why the location was in the fault intercourse place.The results of the location calculating and focal mechanism show that the aftershocks were not occurred at same fault, which the main shock occurred on it, but at several faults around main fault. It means when main shock happened the stress on the fault changed, this effect the stress balance of other faults around it. Some of the aftershock is just for adjusting the balance of stress on the faults.
第一章 介绍了对数字地震台网记录的1991年11月1日大同-阳高5.6级主震后的部分余震系列的精确定位过程。
中国地震局地球物理所的王鸣和腾云田等在1999年11月1日大同5.6级地震发生后,在主震的震中区附近用数字地震仪对余震进行了近场观测。我们整理了1999年11月7日至11月18日的观测记录资料,利用SHM地震分析处理软件对余震系列的震相到时进行了拣取,根据山西地质条件和王培德等的地层速度模型建立了速度模型,用可以调整模型参数的定位程序HYPO71对此部分余震系列进行了定位计算。将定位结果绘制于大同-阳高极震区附近构造图上,显示这部分余震主要分布在近东西走向的六棱山山前断裂带、北西西走向的团堡断裂和北东北方向的大王断裂的交汇带上。与地质调查提供的断层活动资料比较,大同余震基本上是位于大王到秋林这一段处于地质上的最活动断裂带上。
第二章 描述了为余震记录中波形数据记录清晰完整的18个余震,测定其震源机制解的过程和结果。采用水平分层介质中计算理论地震图方法,通过调整大王、后贵仁和堡村三个台站的沉积层的厚度模型使得计算理论地震图所得到直达波Sg-Pg的走时差与实际记录波形的Sg—Pg的走时差一致。转换原始的加速度记
This article is for a master degree. An earthquake with magnitude Ms 5.6 hit the place from Pucun village to XituanPu village, Datong county, Shanxi province in the first of November, 1999. An aftershock sequence followed the main event. The location and mechanism of partial aftershocks were illustrated in this paper. We located 31 events, which are well recorded, and 18 of them, which have clear waveform, were chosen to calculate the mechanism. We use the software "Seismic Handler" and HYP071 program for location. And we use the moment tensor inversion program to calculated focal mechanism. The process of moment tensor inversion is in frequency domain. The location result shows that the aftershock sequence is at an intercourse of EW striking Liulengshang fault, the NE striking Dawang fault and NW striking TuanBao fault. The mechanism shows that the movement of aftershock is on strike-slip fault. But the strikes of different events are not at same orientation. This is why the location was in the fault intercourse place.Chapter one describes the location process. Staff of the institute of geophysics set up a temporal digital seismic network around the meizoseismal region after the magnitude 5.6 earthquake of November 1st, 1999. We sort out the record of the aftershock sequence began from the eleventh of November to eighteenth, using the software of "Seismic Handler" for phase time picking and HYPO71 program for calculating the hypocenter location. We get the velocity model by refence from "rupture activities of Datong in Oct., 1989 and Mar., 1991" ( Wang and Stammler, 2001., in Chinese). The epicenter distribution map shows that the location of aftershock is fit for the activity of faults locating in Datong, Shanxi area.Chapter two describes the way to use the moment tensor inversion program to calculating the focal mechanism of 18 events, which have clear waveform among the well located 31 events. The resolution of mechanism shows that the movement of aftershock event is on strike-slip fault. But the strikes are not at same orientation. This is why the location was in the fault intercourse place.The results of the location calculating and focal mechanism show that the aftershocks were not occurred at same fault, which the main shock occurred on it, but at several faults around main fault. It means when main shock happened the stress on the fault changed, this effect the stress balance of other faults around it. Some of the aftershock is just for adjusting the balance of stress on the faults.
引文
1.徐锡伟、邓起东,1988.晋北张性区盆岭构造及其形成的力学机制,中国地震,4,2,19—27.
2.王培德、S. Klaus,2001.1989年10月和1991年3月大同地震的活动断裂,地震地磁观测与研究,21,6,19—25.
3.陈运泰、吴忠良、王培德、许力生、李鸿吉、牟其铎,2001.数字地震学,北京,地震出版社,96-145页
4.陈运泰、吴忠良、倪江川、王培德、王鸣,1994.近震源宽频带记录的地震矩张量反演,地震学报 16(2):141-152。
5.李旭、陈运泰、王培德,1994.水平层状介质中理论地震图计算程序的使用说明 国家地震局地球物理研究所 北京。
6.徐锡伟、吴卫民,张先康、马胜利、马文涛、于贵华、顾梦林、江娃利,等著.2002.首多圈地区地壳最新构造变动与地震 科学出版社,中国地震局地质研究所论著 F0001
7.K.E、B.A博尔特。地震学引论 1999 地震出版社。
8.苏宗正、程新原,1989年大同—阳高地震的地质环境与地震构造 山西地震,1992年3月第一期 总第68期
9.丁学文、丁有礼、郭星全、郭俊杰 王跃杰。1999年山西大同—阳高5.6级地震宏观烈度考察报告 山西地震 第一期 总第100期 2000年1月
10 大同-阳高地震现场分析组.1992,1989年大同-阳高地震现场分析预报工作回顾山西地震,1992年3月第一期 总第68期
11. Lee W H K and Lahr, JC, 1972. HYPO71 (revised): A computer program for determing hypocenter, magnitude and frist motion pattern of local earthquake, U S Geology Survey, Open-File Rept. 73-311a.
12. Stammler K, 1993. SeismicHandle-Programble mutichannel data handler for interacter and automatic processing of seismological analysese,Computer and Geoscience, 19 (2): 135～140
13. D. Legrand and B. Delouis, 1999, Determination of the fault plane using a single near-field seismic station with a finit-demention source model, Geophys. J. Int, 138, 801-808.
14. Fabrizio Marra, 1999- —, Low-magnitude earthquakes in Rome: structural interpretation and implications for the local stress field, Geophys. J. Int. 138, 231-243.
15. Bernd Schurr and John Nabelek, 1999. New techniques for the analysis of earthquake sources from local array data with an application to the Scotts Mills, Oregon, aftershock sequence, Geophys. J. Int., 137, 585-600
16. V. Lanza, D. Spallarosa, M. Cattaneo, D. Bindi and P. Augliera, 1999. Source parameters of small events using constrained deconvolution with empirical Green's functions, Geophys. J. Int. 137, 651-662.
17. Denis Hatzfeld, Maria Ziazia, Despina Kementzetzidou, et al, 1999. Micrpseismicity and focal mechanism at the western termination of the North Anatolian Fault and their implications for continental tectonics, Geophys. J. Int., 137, 891-908.
18. E. Jacques, J. C. Ruegg, J. C. Lepine, P. Tapponnier, G. C. P. King and A. Omar, 1999. Relocation of M>= 2 events of the 1989 Dobi seismic sequence in Afar: evidence for earthquake migration, Geophys. J. Int., 138, 447-469.
19. R. Tibi, C. H. Estabrook and G Bock, 1999. The 1996 June 17 Flores Sea and 1994 March 9 Fiji-Tonga earthquakes: source processes and deep earthquake mechanisms, Geophys. J. Int., 138, 525-642.
2.王培德、S. Klaus,2001.1989年10月和1991年3月大同地震的活动断裂,地震地磁观测与研究,21,6,19—25.
3.陈运泰、吴忠良、王培德、许力生、李鸿吉、牟其铎,2001.数字地震学,北京,地震出版社,96-145页
4.陈运泰、吴忠良、倪江川、王培德、王鸣,1994.近震源宽频带记录的地震矩张量反演,地震学报 16(2):141-152。
5.李旭、陈运泰、王培德,1994.水平层状介质中理论地震图计算程序的使用说明 国家地震局地球物理研究所 北京。
6.徐锡伟、吴卫民,张先康、马胜利、马文涛、于贵华、顾梦林、江娃利,等著.2002.首多圈地区地壳最新构造变动与地震 科学出版社,中国地震局地质研究所论著 F0001
7.K.E、B.A博尔特。地震学引论 1999 地震出版社。
8.苏宗正、程新原,1989年大同—阳高地震的地质环境与地震构造 山西地震,1992年3月第一期 总第68期
9.丁学文、丁有礼、郭星全、郭俊杰 王跃杰。1999年山西大同—阳高5.6级地震宏观烈度考察报告 山西地震 第一期 总第100期 2000年1月
10 大同-阳高地震现场分析组.1992,1989年大同-阳高地震现场分析预报工作回顾山西地震,1992年3月第一期 总第68期
11. Lee W H K and Lahr, JC, 1972. HYPO71 (revised): A computer program for determing hypocenter, magnitude and frist motion pattern of local earthquake, U S Geology Survey, Open-File Rept. 73-311a.
12. Stammler K, 1993. SeismicHandle-Programble mutichannel data handler for interacter and automatic processing of seismological analysese,Computer and Geoscience, 19 (2): 135～140
13. D. Legrand and B. Delouis, 1999, Determination of the fault plane using a single near-field seismic station with a finit-demention source model, Geophys. J. Int, 138, 801-808.
14. Fabrizio Marra, 1999- —, Low-magnitude earthquakes in Rome: structural interpretation and implications for the local stress field, Geophys. J. Int. 138, 231-243.
15. Bernd Schurr and John Nabelek, 1999. New techniques for the analysis of earthquake sources from local array data with an application to the Scotts Mills, Oregon, aftershock sequence, Geophys. J. Int., 137, 585-600
16. V. Lanza, D. Spallarosa, M. Cattaneo, D. Bindi and P. Augliera, 1999. Source parameters of small events using constrained deconvolution with empirical Green's functions, Geophys. J. Int. 137, 651-662.
17. Denis Hatzfeld, Maria Ziazia, Despina Kementzetzidou, et al, 1999. Micrpseismicity and focal mechanism at the western termination of the North Anatolian Fault and their implications for continental tectonics, Geophys. J. Int., 137, 891-908.
18. E. Jacques, J. C. Ruegg, J. C. Lepine, P. Tapponnier, G. C. P. King and A. Omar, 1999. Relocation of M>= 2 events of the 1989 Dobi seismic sequence in Afar: evidence for earthquake migration, Geophys. J. Int., 138, 447-469.
19. R. Tibi, C. H. Estabrook and G Bock, 1999. The 1996 June 17 Flores Sea and 1994 March 9 Fiji-Tonga earthquakes: source processes and deep earthquake mechanisms, Geophys. J. Int., 138, 525-642.