1995, 17(2):1-4.
Abstract:光阴似箭,30年弹指一挥间。在那难忘的1965年,西北边捶地区三线建设正搞得热火朝天,许多重要工程纷纷上马,国家急需提供有关地域的地震基本烈度预测意见以作为抗震设计的依据。
1995, 17(2):5-19.
Abstract:By using 3-D finite element method,author studied and calculated the interaction between the source fault and the deep upright fault on the same plane before,during and after a strong earthquake and the near field transverse fault which is locked because of the dislocation of the deep upright fault. The following results are obtained:(1)Before a strong earthquake occurs,the deep fault units under the adjustment units have higher shear strain level with the result that the deep fault has a diapirism at the bottom of the seismic source fault during the earth-quake,namely,the deep fauIt units under the adjustment units first reach the fracture limit and split.(2)The adjustment units at the ends of earthquake source and transverse fault with the creeping capacity might prevent the earthquake faults from splitting.(3)A strong earthquake fault's splitting spreads to transverse fault, which could not make the transverse fault locked but may make the deep fault splitting spread. The shallow transverse fault is twisted and locked when the deep fault's splitting spreads to the bottom of the shallow transverse fault.Meanwhile,the seismometry quota concerned with the locked transverse fault appears, this quota is the very small earthquake belt which is controlled by the deep fault.(4)The resigning capacity of the adjustment units is limited during a strong earthquake,it may give rise to strong aftershocks the ends of the source fault.
Liu Guiping , Shi Yaolin , Ma Li
1995, 17(2):20-25.
Abstract:In this paper a 2-D cellular automation model of seismicity is designed,the seismicity of the synthetic earthquakes is analyzed and the physical mechanisms of field precursors and source precursors before a strong earthquake are discussed.The results show that the clustering,frequency-magnitude power law relation and spatial transfer probability of synthetic earth-quakes are consistent with the actual earthquakes.
1995, 17(2):26-32.
Abstract:The migration of earthquake activity is a feature of earthquake activity,and it outlines both activity of seismotectonic zone and earthquake mechanics,In this paper,by studying the change regularity of spatial distribution of strong earthquake with time in Qinghai-Tibet plate and its periphery,it was found that earthquake activities had migrated from south to north then from north to south since 1978,and the migration had abvious relation with earthquake activity period.In view of the regularity,the evolution and development of the earthquake dynamics are discussed,thus the tendency of earthquake activities in the future few years is judged.
Wang Zhenya , Qian Jiadong , Guo Daqing , Li Zuotang , Sun Jingfang
1995, 17(2):33-39.
Abstract:In this paper the direct computing method of precursor information content of anomalies is put forward,and the transformation of non-dimensional precursor information content of precursory anomalies of various observation data has come true. By means of this method we have accomplished the calculation of precursor information content of correlative anomalies which are extracted from the difference values of five-day average from 92 observation items distributed over Gansu,Ningxia and Qinghai.On the basis of reviewed research on the 24 Ms ≤ 5.0 earthquakes we have obtained effective average information contents of unit anomaly about 92 observation items,which become not only important references for earthquake prediction but also a good foundation for the further research on the precursor index system. According to the statistical analysis on the change characteristics of precursor information of Ms ≥ 5.0 earthquakes,the reference indexes of three elements of earthquake prediction are given.
1995, 17(2):40-45.
Abstract:By the synthetically comparing observation of the gas Rn with the volumetric strain,air pressure,water level,water temperature and atmospheric temperature at Shunyi station in Beijing,it is found that in the curves of daily changes of gas radon from ground water there exists a tide phenomenon,and its value is closely related with the theory value of volumetric strain solid tide. To predict earthquake by using data is a new probe of geochemistry methods,so this work provides real observation base for its deep going study.
Zhang Wanxia , Xiang Hongfa , Li Rucheng
1995, 17(2):46-50.
Abstract:Based on soil-radon profile survey across the Xiadian buried fault,the authors discovered that the positive anomaly area of radon in soil occurs on surface projection of the hanging wall of the buried fault.The is ogram of radon near the fault shows that the distribution of radon values along the fault has an obvious gradient zone.
Chang Qiujun , He Genqiao , Song Yulan , Cao Chunping
1995, 17(2):51-56.
Abstract:Based on processing,analyzing and comparing of fault product gas Rn data from Jan.,1991 to Mar.,1994 at Jiayuguan measurement point with meteorological factors,such as geotemperature,air temperature,atmospheric pressure,wind speed,etc., it is found that influence of geotemperature on gas Rn is much less than that of air temperature and the annual variation phase of geotemperature is later than air temperature and fault product gasRn. In addition,the mechanism of influence of geotemperature on the escape of under groundgases is primarily analyzed.
1995, 17(2):57-62.
Abstract:In this paper,relationship between natural geoelectric potential observed at Jiashan station of Anhui Province and moderate earthquakes(ML ≥ 4.5,△ ≤ 300km)around this station has been studied based on the all curves of daily means from 1974 to 1993. According to the field experiment results in 1979,the better response of natural potential to the moderate earthquakes in the 1970s is probably caused by the positions where west measuring electrode is sensitive to earthquake preparation. In the seismogenic process,the variations of regional tectonic stress field result in changes of the level,physical properties and chemical constituents of ground water around the west measuring electrode,thus make natural potential EWE rise or drop by a big margin.
1995, 17(2):63-67.
Abstract:An earthquake results from release of strain energy of an active fault under the action of regional tectonic stress field.The seismic failures of surface buildings and structures as the results of the action of tectonic stress field certainly have the same mechanical properties as the seismic deformation belt.In the present paper.the author fully proves the existence of predominant directions of seismic ground motion by analyzing the earthquake disasters of some strong shocks and points out its importance in earthquake resistance and disaster prevention.engineering designs against earthquake and earthquake damage prediction.
Hou Kangming , Han Youzhen , Zhang Shoujie
1995, 17(2):68-75,81.
Abstract:On the basis of further deduction of diffusion equation,the profiles of single-shock and multi-shock fault scarps along middle and eastern segments of Changma fault zone are fitted and calculated by using mathematical equation models Ⅰ,Ⅱ and Ⅲ. The disperse fault scarps along the Altun fault zone and Changma fault zone are analyzed by using the maximum slope value-fault throws(tgθs-2a)pattern. The results show that for the fault scarps of Changmafault zone the mass diffusion coefficient K=2.1-3.4m2/103 a and along Altun fault zone there are 4 sets of seismic fault scarps whose ages are 0.6 ka,2-2.7 ka, 4ka and 6-6. 6 ka respectively.
Lu Haojiang , Lei Tucheng , Chen Huiqiong , Yang Zhihui
1995, 17(2):76-81.
Abstract:Since late Pleistocene,the activity of fault blocks along continental margin has been characterized by elevation and subsidence movements. The strong overseas earthquake occurring in Quanzhou on December 29,1604, related closely to fault block activity in the area. In this paper,we analysed the relation and discussed the dislocating way of hypocentral fault surface of this strong earthquake.
Wei Dehong , Zhang Shuxun , Zhang Huifang
1995, 17(2):82-83,88.
Abstract:众所周知,震级问题是国内外地震学家非常关心并一直在探讨的重要课题。
1995, 17(2):84-86.
Abstract:一百多年来布格重力异常及均衡重力异常的概念与物理意义的认识在不断深化,今天继续深入研究它们的物理意义,对于探讨地壳运动及地震发生的根本原因,仍然有着很重要的现实意义与科学价值。
1995, 17(2):87-88.
Abstract:单路无线遥测地震传输设备,即78-11机(47mHz)经过多年的运行,部分机元器件老化,可靠性逐年下降,尤其在接收中心随着改革开放的潮流各种民用固定和移动电台数量剧增,使接收中心的干扰场强发生了很大的变化。
Ma Dongtao , Shi Yucheng , Li Honglian
1995, 17(2):89-96.
Abstract:Longnan region lies in the translational area among Qinghai-Tibet Plateau,Loess Plateau and Sichuan Basin and belongs to the superimposed weak belt in geological structure,stratigraphic properties, geomorphology, climate and vegetation,so the slope gravitational process,such as debris flow,landslide,rockfall, etc.are most conspicuous in this region,It is one of the four main gravitational disaster areas in China,Based on predecessors works and field investigation,this paper studies the definition and types of slope gravitational processes(SGP),especially analyzes their features, such as vertical zonality.regionality,seasonal variation, periodiclty.inheritability,paragenesis,etc.,thus brings to light their activity laws.
Sopyright:China Earthquake Engineering Journal