Abstract:On the base of research projects and practice work for earthquake prediction in past sereveral years, the common features of the increase of seismicity, the evolution of abnormities precauser in colony style, the key precursory abnormities and key phenomena of seismicity in Qilianshan seismic belt are studied systematically. A compositive scheme of earthquake short-term prediction in the region is summarized and epurated.

Abstract:InSAR（Interferometric Syntheic Aperture Radar） is a new microwave remote sensing technique with great developing potential. It can be applied to form DEM（Digital Elevation Model）, mapping and monitoring minor terrestrial deformation in large area. In this paper, considering the reference surface, terrain and surface deformation, the interferometric phase decomposition in InSAR is analyzed and discussed from geometry point, and the relevant function expressions of specific phase components are presented. Then the basic principle of generating DEM and acquiring deformation is described. Finally, taking JERS and ENVISAT data as example, application and process of DEM formation and earthquake deformation field abstraction are displayed.

Abstract:Thin-layered method （TLM} is very efficient to study the wave propagation in layered media, and boundary element method （BEM） is very precise to solve infinite domain problems. Combining the advantages of two methods, the BEM, in which Green function is as fundamental solution of stratified half-space obtained by TLM, is used in this paper for analyzing the dynamic problems in stratified foundation. It is an efficient tool for dynamic soil-structure interaction problems. The effects of active vibration isolation by 3D open trench in rigid upper layer and soft lower layer or soft upper layer and rigid lower layer visco-elastic foundations are analyzed in detail. The results show that vibration isolation effect can be relatively good in both cases. The vibration isolation effect is greatly affected by the parameters of layered foundation.

Abstract:Migration is one of the. most significant methods in ground-penetrating radar data processing. In this paper the Fourier finite-difference technique is used for migration of phased-array ground-penetrating radar real PGPR data in 2D media. It shows excellent results to reveal the efficiency of the method, also prove the superior science research value of PGPR and give direction for consummating the apparatus next step.

Abstract:In this paper, the data processing-Solution of APRGP GPS 3 observation epochs from 1999 to 2001 is given. The position estimation of each station in 3D rectangular coordinate system under ITRF97 frame is given by using GAMIT/GLOBK software, while the velocity Tield based on the data of re-occupied sites is computed and crust deformation of this region is also analyzed.The result shows that Asian mainland plate rotates＂ clockwise, and been extruded by Indian plate and Australian plate from south-west, while the stations in western Pacific Ocean move toward northwest. All these features areconsistent with those conclusions achieved by using GPS data from regional networks in China, while this paper provides the information on crust deformation in a wider region within Asia and the Pacific Ocean.

Abstract:In this paper, according to the integral representation theorem of elastdynamies, an integral equation in transformed filed that represents the displacement field in homogeneous body has been deduced by using Laplace transform. Furthermore, an integral equation in transformed filed, which suited to calculate the instantaneous elastic wave scattering by a number of irregular scatterers embedded in an elastic body is derived.

Abstract:A mid-long term earthquake prediction model is formed using project pursuit auto-regression model, with independent variable sequence in 5 years of time window and 1 year of time interval, for different study regions of Xinjiang. Meanwhile the characters of strain accumulation and release during different periods in the study regions are discussed with strain accumulating and releasing model, and the future seismic trend are judged according to strain accumulating level and period character of seismieity in the study regions. Afer synthetically analyzing both seismic trend conclusions from two models, the earthquake hazard judgment within future 5 years （2006-2010） for every study regions in Xinjiang are given.

Abstract:The characteristics of seismogenic structure and tectonic backgrounds of 9 Ms≥ 5. 0 earthquakes occured in Gansu Province since 1995 are summarized, the generalities and distinctive features of the structures are analyzed. The results indicate that： most of the middle-strong earthquakes in recent 10 years in Gansu main occured on the secondary active fault zones, where activity is weak, or on the edge of main fault zones. The earthquake are results of regional stress field adjustment, and their characteristics are occuring by stages in time, distributing in divisional zones in space and migrating from the front of Mountain to the interior of thrust basins.

Abstract:The electrical characteristics of buried fault in different environment, and the curve shape of resistivity composite profile for different kinds of fault. The process of buried fault prospecting by superficial direct-current electrical method is illustrated by real some cases. The results show that superficial direct-current electrical method is valid to the detecting of some kind of buried fault but the prior knowledge is very important and is the key to the efficiency of prospecting and the interpretation of result.

Abstract:It is a reasonable explanation that the slope mass vibrating process makes the slope deformed and failed during earthquake, and initial violent-slide velocity of the slope mass will affect the sliding velocity and all the slippage later. The maximum slippage could be divided into two parts for calculation, which are the slope displacement during earthquake vibration and the sliding distance after earthquake. The former will be computed by Newmark analytical method, and the later will be done further when permanent displacement has occurred. A landslide formed in Haiyuan earthquake in 1920 is taken as an example. The calculating result proves that the formulae are practical and effective.

Abstract:Many hot springs distribution in Tianshui city and Its northern-southern adjacent areas. In this paper, the regional and deep geological background and the geothermal mechanism for the hot spring forming are discussed, based on its geological and geophysical fields analysis. In this region, the tectonic faults with NS direction develop, neutral-acid intrusive rocks and alkaline basalt eruptive rocks form two nearly NS direction magmatic rock belts. In the depth, the rheosphere is some shallower and leithosphere is thiner than other regions, where thermal material from upper mantle gushed up and caused Mohole uplifting. In middle crust both low velocity layer and high conduct layer appear together. On the surface, the thermal current values increase and hot springs distribute as net shape. This region is a favourable exploring region for upliftfracture-convection type geothermal resources in Gansu province.

Abstract:Geology hazard frequently happens in Hubei province and its adjacent districts, like slope landslide, geosutume and land collapse. Based on the authors＇ experience in disaster prevention and mitigation works for many years, the types of slope and its deformation and destruction mechanism in different geomorphology are brought forward.

Abstract:Using the method of receiver function the S-wave velocity structure under Gansu seismic network is studied. It is concluded from the inversion results that the crust under Gansu seismic network consists of two layers, the depth of the first layer is between 20 km and 25 km; the second interface is Moho, with the average depth of about 50 km. The velocity above this interface is about 3.8 km/s,and on bottom of this interface is about 4.5 km/s.

Abstract:The basic matters of Wuwei geo-resistivity station including its location,observation instrument, pole arrangement and observation environment are introduced first. Based on the observation data of geo-resistivity from 1983, the anomaly characteristics before Ms≥5.0 earthquake events in Gansu province and adjacent regions with their geotectonics, electricity property condition and reflecting earthquake abilities are analyzed. The result could afford relatively credible criterion to the three essentials of earthquake prediction in the middle and west Qilian Mountain.

Abstract:In active fault zone there is a lot fluid which may not only alter the strength of fault zone, but also change stress and trigger earthquake. In this paper the recently research on the characteristics and types of fault zone,as well as source and fluxion of the fluid in thd zone are described,the discussion on influence of the fluid and the role of the fluid in earthquake pregaration process are also introduced.

Abstract:Tectonic geomorphology has been rapidly developed from experiential science to modern science with high techniqnes. Based on analysis of relative documents, the characters, contents, research methods of this learning branch are presented, and its research progress in China is reviewed and summarized in this paper. Finally, the future research direction of tectonic geomor- phology is discussed.

Abstract:In primarily function exploring .in automatization of seismic thematic mapping based on GIS, the seismic special subject sign database based on the TrueType techniques is developed, the method of showing line type and planar type signs in the mapping are presented, and some shortages of Maplnfo in marking function for the mapping are improved by twice exploring the software. The new techniques could basicly satisfy the need of seismic thematic mapping.