景泰地震台短周期地震仪记录的几种异常波形特征与景泰6.2级地震的关系     

姚同福  付印发  王先 《华北地震科学》1996,(1)

本文研究了景泰地震台记录到的几种异常地震波形的形态特征及随时间分布特征,采用测震学的方法和数理统计的方法,对各个阶段的异常波形出现的数量、类型和振幅进行了定量分析,发现在1990年10月20日景泰6.2级地震前,异常波形数量明显地呈平静一密集交替出现的现象;临震前各种异常波形的数量增多,振幅增大,异常持续时间增长,震后异常波形很快衰减并消失.与其他前兆对比,可以认为异常波形的出现可能与景泰地震的孕育过程有关,根据该类波形的变化特征有可能对地震作出预报.  相似文献   

华北震后趋势判断的前兆综合指标与方法   总被引：1，自引：0，他引：1  

傅德川  张子广  王秀文  赵新平 《华北地震科学》1996,(2)

在对华北邢台、渤海、海城、唐山、大同五大震例的各前兆学科震后变化进行分析的基础上,本文归纳出综合判断后续地震异常的3项定量指标与4项定性指标,还给出了模糊综合评判的方法并计算出符合实际的结果,当评判有震时又给出预报后续地震三要素的经验性判据.  相似文献   

唐山7.8级强震孕育条件及前兆场时空演化的三维数值模拟计算与分析   总被引：1，自引：0，他引：1  

冯德益  舒立德 《华北地震科学》1996,14(4):1-10

首先对由深部地震测深剖面观测综合归纳出一个华北地区岩石圈１２层三维非均匀实际模型在承受和不承受来自底面的上拱力条件下的应力场进行了数值模拟计算，并根据计算结果对唐山地震孕震条件及长期前兆进行分析研究。  相似文献   

地电短临前兆产生机理及一种新的短临预报方法（谐振预报法）   总被引：3，自引：0，他引：3  

钱复业  赵玉林  赵跃臣  沈启兴  徐忠信 《华北地震科学》1996,(3)

研究了地电短临震兆机理，在此基础上给出了引潮力触发地电短临前兆模式。据此从理论上分析了地电临震震兆特征，并以唐山７．８级大震为例，从实际观测中检出具有此模式特征的震兆（具有起潮力特征），从而验证了所提模式理论的客观存在的可能性。最后给出与此有关的地电短临预报方法。即，根据脆性岩石失稳的相对刚度比较准则，定义部分岩体刚度λ＝０的状态为临震阶段，分析λ＝０时起潮力引起位移的特征和规律，得出原地监测岩体刚度是否为零（进入临震阶段）的方法。因为在弹性阶段，λ为较大正值，微小的起潮力只引起微小的位移，此时的电响应甚小，通常检测不到；但随着构造力的积累，介质进入临震阶段，此时同样微小的起潮力却可引起甚大的位移（λ＝０时，位移为无穷大），从而产生可检测的电响应。由于这种电响应具有与起潮力相同的周期，故可把临震电响应同各种干扰区分开，判定为临震前兆，从而建立了地电临震前兆起潮力触发模式，并可给出相应的短临预报方法。对１９７６年唐山７．８级强震前后震中周围地电阻率及大地电场实测资料进行谱分析，发现仅在主震前二个月至半月内，两种不同物理本质的电响应分别出现与起潮力ＭＳ波与ＭＳｆ波周期相同的异常变化。这是对所提临震前兆模式和预报  相似文献   

Morphological characteristics of the earthquake surface ruptures on Awaji Island, associated with the 1995 Southern Hyogo Prefecture Earthquake   总被引：1，自引：0，他引：1  

Aiming  Ian Shinichi  Uda 《Island Arc》1996,5(1):1-15

Abstract The earthquake surface ruptures on the northern side of Awaji Island accompanying the 1995 Southern Hyogo Prefecture Earthquake in Japan consist of three earthquake surface rupture zones called the Nojima, Matsuho, and Kusumoto Earthquake Surface Rupture Zones. The Nojima Earthquake Surface Rupture Zone is - 18 km long and was formed from Awaji-cho at the northern end of Awaji Island to Ichinomiya-cho. It occurred along the pre-existing Nojima geological fault in the northern segment and as a new fault in the southern segment. The northern segment of the Nojima Earthquake Surface Rupture Zone is composed of some subparallel shear faults showing a right-step en echelon form and many extensional cracks showing a left-step en echelon form. The southern segment consists of some discontinuous surface ruptures which are concentrated in a narrow zone a few tens of meters in width. This surface rupture zone shows a general trend striking north 30°-60° east, and dipping 75°-85° east. The deformational topographies and striations on the fault plane generated during the co-seismic displacement show that the Nojima Earthquake Surface Rupture Zone is a right-lateral strike-slip fault with some reverse component. Displacements measured at many of the outcrops are generally 100-200 em horizontally and 50-100 em vertically in the northern segment and a few em to 20 em both horizontally and vertically in the southern segment. The largest displacements are 180 em horizontally, 130 em vertically, and 215 em in netslip measured at the Hirabayashi fault scarp. The Matsuho Earthquake Surface Rupture Zone striking north 40°-60° west was also found along the coastline trending northwest-southeast in Awaji-cho for ～1 km at the northern end of Awaji Island. The Kusumoto Earthquake Surface Rupture Zone occurred along the pre-existing Kusumoto geological fault for ～ 1.5 km near the northeastern coastline, generally striking north 35°-60° east, dipping 60°-70° west. From the morphological and geomorphological characteristics, the Nojima Earthquake Surface Rupture Zone can be divided into four segments which form a right-step en echelon formation. The geological and geomorphological evidence and the aftershock epicenter distributions show clearly that the distributions and geometry of these four segments are controlled by the pre-existing geological structures.  相似文献   

中国东部特殊地震带研究   总被引：1，自引：0，他引：1  

肖和平 《地震工程学报》1996,18(2):12-17

综合分析了中国东部湖南、湖北、广东等省的水库地震和矿山地震特征，并根据区域地震地质、深部构造等资料，初步确立了特殊地震带──诱发地震活动带。结果认为鄂湘粤地区之所以形成特殊地震带，是与现代活动的秭归－常德－河源深断裂带有关。  相似文献   

天水地震区深部地温场的有限元计算   总被引：2，自引：0，他引：2       下载免费PDF全文

董治平  郭守年  蒋梅  刘宝勤  张立光 《地震工程学报》1996,18(3):48-53

用有限元方法计算了天水地震区上地壳地温场。结果表明，影响该区浅部（层）地温场的主要因素是基底构造和断裂构造。祁连褶皱系为高热异常区，秦岭褶皱系为低热异常区，西秦岭北缘断裂带为地温梯度带。认为该带历史地震的发生与热应力差有关  相似文献   

大同遥测地震台网小震群活动与大同-阳高中强地震预报讨论          下载免费PDF全文

李祝  薛振岳  赵淑珍  金文臣  秦保燕 《地震工程学报》1996,18(4):17-22

根据大同遥测地震台网记录到的小震群资料，用组合模式理论［１］对本区的小震群时空演化规律进行了分析研究。结果表明，对于１９８９年１０月１８日在本区发生的大同—阳高５．８级地震，利用震前小震群资料得出的预报震中与实际震中有较好的一致性。另外，通过震群与外因相关性的分析，对发震时间的预报也取得了较好的效果  相似文献   

深井电阻率所处井孔位置与地震关系的研究   总被引：1，自引：0，他引：1       下载免费PDF全文

孙承德  顾贞庆  钟国芬 《地震工程学报》1996,18(4):74-76

对鲁南地区近几年发生的４级（ＭＬ）以上有感地震与深井电阻率所处井孔位置的关系进行了研究，进一步证明了“活断层—应力场效应”是存在的  相似文献   

Deterministic sliding block methods for estimating seismic displacements of earth structures   总被引：5，自引：0，他引：5  

Z. Cai  R.J. Bathurst 《Soil Dynamics and Earthquake Engineering》1996,15(4):255-268

A review and quantitative comparison of existing deterministic sliding block methods for predicting permanent displacements of earth structures subjected to seismic loading is presented. The reviewed sliding block methods are divided into two main groups based on the characteristic earthquake parameters referenced in each method. One group uses the maximum horizontal ground acceleration and velocity, and the other uses the maximum horizontal ground acceleration and the predominant period of the acceleration spectrum. Displacement functions published by previous authors are reformulated to give common non-dimensionalized displacement functions of the critical acceleration ratio which are then used to compare the different methods for the estimate of permanent seismic displacement of soil structures. The results show that despite the fact that the different methods were formulated using a wide range of earthquake records and different characteristic seismic parameters, permanent displacement values predicted using these methods fall within a reasonably narrow band. Selected acceleration data from three recent earthquakes that occurred in California are used to evaluate and compare the accuracy of the reviewed displacement methods for practical applications.  相似文献