SHI Ya-liu , ZHOU Min-du , ZHANG Xiao-dong , NING Shu-nian
2004, 26(4):289-292.
Abstract:For handling information uncertainty in earthquake prediction, possibility theory and statistics have been the primary method. But in many cases,this method can't produce effective results. For this reason, a new uncertainty method——Evidence theory is introduced in this paper. At first, the representation of uncertainty for earthquake prediction under the frame of this theory is introduced. Then the general procedure of prediction with the D-S combination rule is discussed,and in accordance with the earthquake synthesizing prediction need, the weighted D-S rule is produced.From our study,it is concluded that the method introduced holds its own effectiveness in earthquake prediction.
2004, 26(4):293-297.
Abstract:The research region is divided into many rectangles with fixed width, and densities and thicknesses of the rectangle units are taken as model parameters. On this base, the objective function of inversion of gravity anomaly is formed, and the partial derivative tensors for the model parameters are also calculated. Then the Ridge Regress Procedure is employed to inverse gravity anomaly in order to obtain the densities and their interfaces.The method is used in inversion test for two theoretical models.
YU Huai-zhong , YIN Xiang-chu , LIANG Nai-gang
2004, 26(4):298-302.
Abstract:According to Load/Unload response ratio(LURR) theory, the damage evolution of source media in the critical seismogenic region can be reflected by LURR values. In calculating LURR value, many physical parameters can be regarded as response, such as Benioff strain, modulus. In this paper, the different evolutions of LURR values using these different physical responses are investigated by experiments and theoretical methods. The results indicate that before the LURR values reach the peak value, the similar evolutions of LURR values are observed.
2004, 26(4):303-308.
Abstract:A new reverse fault zone,60 km long,was found on the alluvial and pluvial fan of the northern bank of Bayinguole river, Delingha, Qinghai Province. The fault is a sub-extrusion tectonics belongs to the northern margin of NNW-NWW oriented active fault system in Qaidam basin. Its tectonic geomorphology is characterized by clear linear fault scarps, the average vertical slip rate of the fault is about 0.41±0.27 mm/a since late period of the late Pleistocene. About three palaeo-earthquake events are found by trenching along the active fault zone, their ages are 32.7±1.45 ka, 15.54±1.32 ka and 3.2±0.335 ka, respectively.
2004, 26(4):309-314.
Abstract:Using the data of seismic accelaration on both soil surface and rock recorded in Shanghai area in Taiwan MS7.5 earthquake on March 31,2002,the amplification response of ground motion for S wave on soil coverage is discussed.The acceleration time-history curves of S wave on the rock and soil coverage of Shanghai city in possible future MS8 earthquakes are composed with empirical Green-function,and its influnce on high buildings is estimated preliminarily.The result could be useful to aseismic designing of high building in Shanghai.
YAO Li-xun , ZHONG Yu-yun , ZHANG Zhen-feng , YANG Gang-yu
2004, 26(4):315-321.
Abstract:In 2002,a reservoir induced earthquake sequence took place in Shanxi reservoir,Wenzhou city,Zhejiang province.The corner frequencies of the earthquakes were prominently less than that of tectonic earthquakes.Based on the theory of wave propagation in two phases medium,the variations of wave velocity, vp/vs ratio and the influence on corner frequency in the process of dilatancy-diffusion, saturation with water and strength weakness of rock mass are discussed.According to some experiment results if the porosity is 0.15 and the elasticity modulus of rock decreases 23%, the corner frequency can decrease about 29%.It indicates that the corner frequency of the reservoir-induced earthquake decreasing is caused by fracture growing and infiltration diffusion of water,which lead to the strength weakness of rock mass.Thus the corner frequence may be used as a criterion for distinguishing the reservoir-reduced earthquakes from the tectonic earthquakes.
2004, 26(4):322-327.
Abstract:In exploration of short-impending earthquake prediction based on the infrared ground temperature anomaly from meteorologic satellites, how to exploit the analyzing-treatment system of the satellite for catching, defining and abstracting the earthquake precursor anomalies, analyze the time-space evolution of the anomalies and erect the prediction indexs for "three factors of earthquake" are introduced in the paper. Some earthquake prediction examples for using this method are given also.
QU Yan-jun , ZHAO Cui-ping , ZHAO Jian-zheng , NIE Xiao-hong , SUN Jia-ning
2004, 26(4):328-333.
Abstract:Using the data of three digital stations which were erected in aftershock region after Bachu-Jiashi MS 6.8 earthquake,Xinjiang Urumqi Autonomous Region,on Feb.24,2003,the S-wave splitting character of the aftershocks is analyzed. The result shows that the polarization direction of fast wave of aftershocks in epicenter region is approximately in NS,which is consistent with the principal compressive stress of the main shock. The delaying times of slow wave before strong aftershocks with MS 5.1 on Mar. 16 and MS 5.3 on Mar. 31 show the characteristic of gradually decreasing in general case.
2004, 26(4):334-338.
Abstract:Shandan geo-electric station is only 43 km from the epicentre of Minle-Shandan MS6.1 earthquake in 2003. The electric variations precursor is obviously recorded at the station during the one year and short-term period before the earthquake, which is the typical precursory electric variation in or near the focal region in the late preparation period of strong earthquake. But the anomalously electric change does not appear in impending period. The main reason is probably the direction of pressure stress in seismic stress field and the station orientation to the event, according to the special relation ship among the imminent anomaly, focal site, active fault and the causative mechanism.
WANG Lan-wei , ZHAO Jia-liu , WANG Zi-ying , WANG Yan-qiong
2004, 26(4):339-342,346.
Abstract:The application of correlation detetion method to testing the signal amplitude of Extramely Low Frequency(ELF) with some software in research of ELF Electro-magnetic Receiver is introduced.The theoretical culculate result and practical observation results at two stations are given also.
WANG Wei-dong , ZHANG Yong-zhi , SHAO Guang-zhou , LIU Guo-hua , ZOU Zhi-wei , DI Xiu-ling
2004, 26(4):343-346.
Abstract:Using the digital seismic data recorded by xi'an digital seismic network, the average value of apparent stresses of earthquakes in the middle and southern parts of Shaanxi province are calculated.The variation of the apparent stress before and after Jingyang ML5.2 earthquake and the relationship between apparent stress and magnitudes are then discussed.
2004, 26(4):347-352.
Abstract:Based on the data of M≥6.0 earthquakes in Chinese mainland from 1975,in a certain scan time and scan radius from the epicenters,10 seismic parameters with clear physical significance and independence are choosed as objects to research the precursor symbol of the seismic parameters near epicenter area before strong earthquake.The result shows that the average corresponding ratio of precursor anomalies in 15 events in southwestern China is 0.77,the ratio in 10 events in northern China is 0.70 and in 18 events in northwestern China is 0.69.So this three numbers can be used as the precursor symbol of seismic parameters in each above rigions.
lIU Yi-gao , HU Cheng , ZHANG Min , LI Li-feng , PAN Hai-tao
2004, 26(4):353-356.
Abstract:S method, which superposes the change values of all survey points in same mobile geomagnetic survey line, can restrain the disturbance to single point and stick out the possible anomalous information of seismic geomagnetic field. In this paper the relationships between S anomaly and small seismic swarm, moderate-strong earthquakes in near region are researched, as well as the correlativity between the S anomaly in "seismic window" area and moderate-strong earthquakes in the connected region. At last the "Changes in same direction" phenomenon of δf values for all survey points in same survey line and in same time is discussed.
ZHANG Yuan-sheng , LIU Qin-huo , GUO Xiao
2004, 26(4):357-361.
Abstract:The situation of application and study of the satellite infrared remote sensing on earthquake prediction is introduced.It is considered that there is a long way from the precent application level of this technology to the need of earthquake prediction.So some important research points for future study are suggested,and the role and prospects of the satellite infrared remote sensing technology in earthquake prediction field are analysed.
AN Zhang-hui , ZHOU Min-dou , WU Qing-ju , BAI Lin
2004, 26(4):362-364.
Abstract:The data of teleseismic P waveform include a lot of informations of P-S converted wave and P multiple reflection wave produced by the interface of crust and mantle underneath the stations. The receiver function obtained from the waveforms offers an approach to understanding of the crust and mantle fine velocity structures. In this paper, the new progress in increasing the stability and precision of the receiver function is introduced. Many mature methods in oil exploration have been lead into the receiver function research field. Application of all these methods shows the inhomogeneity of crust and upper mantle with high resolution.
FENG Xi-jie , DU Wen-he , YUAN Zhi-xiang , HAN Heng-yue , MI Feng-shou , FAN Zeng-jie , REN Juan
2004, 26(4):365-367.
Abstract:Shiquan ML4.9 earthquake on April 24,2003,Shaanxi province,is a typical mainshock-aftershock sequence. The macro epicenter is at Qingnijian, Zhongchixiang,Shiquan County.The meizoseismal region is just on the Liziba-Yingfeng-Tiefosi fault and its long-axis is nearly identical with the fault extended direction. But the attenuation of its biggest velocity of vibration is slower in NS direction than in EW direction, not comforms to the attenuation of intensity isolines.
SHEN Xu-zhang , CHANG Qian-jun , MEI Xiu-ping
2004, 26(4):368-370,364.
Abstract:Taking the recording data of FSQ water tube tiltmeter at Lanzhou deformation station as research object, analysis on the data with methods of configuration analyzing, curve fit, remainder analyzing, dynamic analyzing of tide factor, tide ellipse and tide slanting angle is done, from both non-tidal part and tidal part of recording. The relationship between abnormities in the data and medium-strong earthquakes in regions near the station is researched also. The result shows that the records of FSQ water tube tiltmeter at Lanzhou deformation station has good medium-short response to earthquake occurred in neighboring regions.
LIU Hong-mei , YUAN Zhong-xia , WANG Jun
2004, 26(4):371-373.
Abstract:Based on the endochronic theory, the experiment and study on the model of pore water pressure of saturated loess increasing under dynamic load are done. The results show that the increase of pore water pressure of saturated loess has correlate relationship with the dry density, saturation degree of soil samples as well as the dynamic load.
Zhang Yu-min , Gao Jin-tian , Zhan Zhi-jia
2004, 26(4):374-376.
Abstract:Based on the data of 2 min geomagnetic total field observation in Beijing and its adjacent areas,the frequency spectrum characteristic and the time-space variation of amplitude ratio of frequency spectrum for Beijing station and other 11 temporal stations are analyzed.The results show that the spectrum amplitude of geomagnetic total field in this area appears decreasing tendency with the increasing of period.The amplitude ratio of spectrum between temporal stations and Beijing station varies with time-space changes,which may be related to the underground electromagnetic structures,earthquakes and tectonic activities in this area.
HU Feng-ying , WANG Zhi-min , XIE Jian-jian , HU Wei-jian , HUANG Wei-dong , WANG Jian-jun , LIU Peng
2004, 26(4):377-379.
Abstract:The comparision between the observed data of digital radon and analog radon from Tangcan 1 water well,in Anyang,Henan Prov.,is done.The result shows that the relativity between the digital data and andalog data is weak,and the digital data have more obvious precursor anomaly before earthquakes than the analog data.
GUO Zeng-jian , QIN Bao-yan , GUO An-ning
2004, 26(4):380-380.
Abstract:近年来矿井,特别是煤矿,在开采过程中事故频发,因此矿井灾害的预测就成为一个重要问题。已有的预测方法主要是根据矿井中的声响前兆,煤结构变化前兆,地压方面的前兆和瓦斯方面的前兆。
Sopyright:China Earthquake Engineering Journal