Earthquake—generating Structure Revealed by 1999 Sichuan mianzhu Earthquake Sequence with Ms=5.0     

Zhao Zhu  Wang Bilan  Long Sisheng 《中国地震研究》2002,16(2):147-154

Through the accurate determination of hypocenter location,the measurement of the main focal mechanism solutions and the analyses of time dependent processes for Sichuan Mianzhu earthquake sequence with Ms=5.0 occurred along the middle segment of Longmenshan fault zone on November 30,1999,the distribution of focal depth section,the stress relase and seismicity features are given to reveal the earthquake-geneating structure of the earthquake sequence.The obtained results show the activity features for this sequence as follows:(1) There is no obvious foreshock,the accumulated strain energy releases in nearly pulse way,fluctuation of the seismic activity level is not quite evident during the duration of the sequence,and the statistical relation between the large events and the small events is less compatible with the traditional G-R estimation;(2) The epicenters of the earthquake sequence are not distributed on the main Longmenshan piedmont faults emerging out ground,but near the hidden Longmenshan piedmont faults.The direction of epicenter distribution is not very coincident with the fault strikes.The microscopic epicenters are relatively far from the macroscopic epicenters,The focal depths range from 5km to 16km;(3) The fractures of focal fault plane with the NE strike appear out the strike-slip displacement with a few overthrust components under the major principal compressive stress of NNE direction.From these,we consider it should be paid more attentions to the underground hidden faults near the ground fault zone on a large scale for their generating earthquake risk.  相似文献   

Focal Fault of the 1999 Datong Ms5.6 Earthquake in Shanxi Province   总被引：1，自引：0，他引：1  

Wang Yan  Diao Guiling  Zhang Sichang  Wang Qincai  Liu Yunqing  Zhu Zhenxing  Zhang Yanqing 《中国地震研究》2002,16(4):363-368

Several earthquakes with Ms≥5.0 occurred in the Datong seismic region in 1989,1991 and 1999,The precise focus location of the earthquake sequence was made by the records of the remote sensing seismic station network in Datong.Using that data together with macro-intensity distribution and focal mechanism solutions,we analyze the difference among three subsequences.The results show that the focal fault of the 1999 Ms 5.6 earthquake was a NWW-trending left-lateral strike-slip fault.It is 16km long and 12km wide.It developed at the depth of 5km and is nearly vertical in dip.The two previous earthquake subsequences,however,were generated by activity along NNE-trending right-lateral strike-slip fault.It can be found that the rupture directioin of the 1999 earthquake has changed.It is generally found that a rupture zone has more than two directions and has different strength along these two directions.The complicate degree of focal circumstance is related to the type of earthquake sequences.There is the NE-trending Dawangcun fault and the NW-trending Tuanbu fault in the seismic region,but no proof indicates a connection between focal faults and these two tectonic faults.The feature that focal faults of three subsequences are strike-slip is different from that of the two tectonic faults.It is suggested that the 1999 earthquake subsequence was possibly generated by a new rupture.  相似文献   

Extracting coseismic deformation of the 1997 Mani earthquake with differential interferometric SAR   总被引：2，自引：0，他引：2  

单新建  马瑾  王长林  柳稼航 《地震学报(英文版)》2002,15(4):431-438

Introduction The development and application of Interferometric Synthetic Aperture Radar (InSAR) have a close relationship with the sensors development of Synthetic Aperture Radar (SAR). The conception of SAR is proposed comparatively to the real aperture radar antenna. It is well known that the longer the antenna is, the higher the observation resolution will be. Just limited by the length of the antenna, the resolution of real aperture radar is generally very low and cannot meet the r…  相似文献   

An scientific evaluation of annual earthquake prediction ability   总被引：1，自引：0，他引：1  

张国民  刘杰  石耀霖 《地震学报(英文版)》2002,15(5):550-558

Introduction There have been nearly 40 years for earthquake prediction since the research on earthquake prediction was carried out in plan by some advanced countries since 1960s. For the hard long process of earthquake prediction, Alen, American famous scientist and former president of the evaluation commission of earthquake prediction in California, USA, said that the difficulty of earthquake prediction is more than the expected and the practical progress of earthquake prediction is more sl…  相似文献   

上海地震台阵的地震定位方法   总被引：5，自引：0，他引：5  

赵镇岭  朱元清 《地震地磁观测与研究》2002,23(2):85-96

详细介绍了上海地震台阵数据处理软件系统中的地震定位方法，用台阵的聚束方法得到地震的方位角和视慢度，根据统计得到的视慢度－震中距表推算震中距。并结合了地震台网的定位方法，由单台记录的各类主要震相从J－B走时表得到震中距，然后进行地震定位。该定位方法可对近震、远震进行定位处理，并由深震相得到震源深度。  相似文献   

用于地震调查的航空红外遥感实时传输系统研究     

乔成斌  李茂堂  张瑞青 《地震地磁观测与研究》2002,23(3):15-19

该系统提供了航空红外遥感资料的袢时采集和传输，为及时开展地震野外调查工作提供了一个有力的手段。该系统由红外传感器系统、机载站图像和数据实时处理系统、机载站通信系统、转发站通信系统、地面站接收系统、地面站图像和数据实时处理系统组成。  相似文献   

新疆数字地震前兆台网的数据传输功能分析   总被引：1，自引：0，他引：1  

哈斯高娃  陈勇 《内陆地震》2002,16(3):266-270

为了进一步提高地震前兆数据的传输效率和准确性 ,实现前兆数据采集和管理的自动化 ,对新疆地震局数字化地震前兆台网中心的功能、数据采集原理、数据传输特征进行了分析 ,认为数字化观测技术为地震前兆数据的采集、传输提供了一种高效、可靠的手段  相似文献   

黄海及其沿岸历史地震初步研究     

吴戈  刘昌森  江在雄  翟文杰  吴镝 《四川地震》2002,(2):14-22

黄海及其边缘，经历史地震资料整理，地震参数估定与编目，截至1949年8月，共有M≥3级地震2187次，其中M≥43/4级地震259次，资料显示大致有三个相对集中活跃区，16世纪曾有过历史地震活动高潮。  相似文献   

山西大同——阳高5.6级地震离石台地倾斜异常特征分析     

阎存清 《山西地震》2002,(3):8-12

1999年 11月 1日 ,在山西大同—阳高一带发生了 Ms5 .6地震。山西离石地震台依据该台地倾斜观测出现的异常 ,震前对这次地震作了较好的短临地震预报 ,为了探讨单台地震预报的方法 ,在该次短临预报的基础上 ,进一步用差分法、滤波法、矢量法、形态分析法对观测资料作了进一步的处理 ,发现该台地倾斜震前异常反映较好 ,具有明显的阶段性特征。指出 ,这对山西的地震监测预报有重要的作用。  相似文献   

山西北部至晋冀蒙交界地区几次中强地震前4.0级地震活动的研究     

薛丁  徐建德  阎海滨  张晁军  朱学健 《山西地震》2002,(4):17-21

对山西北部至晋冀蒙交界地区中强地震前的 4 .0级地震进行了研究 ,得出其特征为异常增强—异常平静—信号地震的结论 ,认为该区某些 4 .0级地震活动似可作为某些中强地震的前兆地震而进行进一步的研究。  相似文献