Abstract:The one-dimensional inversions for the MT data in Lanzhou region are respectively conducted by using Occam's and general inverse methods. The two inversion results confirm each other, which make the interpretation more reliable, and the results of the one-dimensional interpretation are consistent with that of the two-dimensional inversion for the same data.

Abstract:The genetic algorithms classifier and principle of classifing system of earthquake prediction based on the genetic algorithms is briefly introduced. The method to design the classifing system of shortterm comprehensive earthquake prediction based on the genetic algorithms is developed. In the method the genetic algorithms is used as the tool to optimize the prediction rules, the lasting times of abnormity is assigned as the codes; the prediction period is three months; and the seismicity is combined with many precursor methods to predict earthquake. As an example, the method is used in North Tianshan seismic zone with multiple parameters. The preliminary calculating result shows that the method has higher self-study correctness and higher ability of testing and predicting.

Abstract:Based on the concept of homogeneous pore fluid and Biot's theory of two-phase media, and using the model of Biot's theory to imitate imperfect saturated porous soil, the theoretical formulation of reflection and transmission coefficients at an interface between imperfect saturated porous soil and ordinary elastic soil for propagation of P wave and SV wave is developed. Numerical results show that only small difference in degrees of saturation may produce substantial influence on the coefficients at interface. The study suggests that we may carefully pay attention to the influence of water saturation on the dynamic analysis of seismic wave.

Abstract:The finite element model for Southwest China is established, and the stress adjustment due to strong earthquake in the region is studied. The preliminary result shows that many strong earthquakes occurred in the area of stress increased.

Abstract:The artificial neural networks is used to prediction of time serial of the earthquake max. magnitudes in mainland of China, and to forecast earthquake max. magnitude for next year. The result shows that the method has good forecasting ability. The result also indicates that seismicity of strong earthquake in mainland of china is not only related with the time serial of strong earthquake but also the seismicity of strong earthquake in the world and the sunspot.

Abstract:By the field investigation and analyses on distribution range, outcrop elevation, field characteristics of Ⅰ~Ⅶ terraces around Dawanzi and Xiaowazi villages in the inner side of the big winding of Yellow river in Shapotou,Zhongwen county,Ningxia province the forming time and evolution procedure of the big winding are discussed. It is obtained that the big winding forming began at the time same as T₅ forming and finished after the T₃ has been formed, about 100 ka to 280 ka B. P..

Abstract:The principle of locating epicenter in array and the necessity of establishing a calibrated database of array are expounded, and the establishing process of the calibrated database of Shanghai array which use seismic data of both Shanghai seismic network and Shanghai array is explained. At the end, the lo cation and range of lateral velocity heterogencity which cause locating epicenter error in the data of Shanghai array are discussed.

Abstract:The evolution processes of middle-small seismic activities before 20 M_S ≥ 5.0 earthquakes occurred in Qilianshan seismic belt since 1980 are studied, by using the curve of energy release and the curve of frequency. The result showes that the phenomenon of increasing middle-small seismic activity before strong earthquakes in the range of 2°×3°near mainshockes exists obviously for 70%of events. The continues time of increasing is about 6~12 months and evolution process can be divided into two styles:A. Background level →increasing →tranquil →eruption;B.background level →increasing →eruption. There is an obviously power index increasing on curve of energy release for increasing area.

Abstract:From May, 1998 to January, 2001, there were 16 large earthquakes (M_S ≥ 7.5)over the world. Based on the two-time method of magnetic storm related to lunar phase, 15 earthquake corresponding time intervals (±5 days)can be computed, and among them 13 occurred in 11 computed time intervals. Meanwhile, other 2 computed time intervals, correspond to 2 earthquakes (7.0 ≤ M_S ≤ 7.4). The research result shows that the first magnetic storm with large storm index (K)correlate to the occurrence of M ≥ 7.8 large earthquake, and the magnetic storms occurred in the lunar phase demonstrate good correlation to the M ≥ 7.5 large earthquakes.

Abstract:The systematic analysis to works of the vertical pendulum tiltmeters in Xinjiang region in nearly 10 years is given. The result shows that this kind of tiltmeter has high observation accuracy, is easy to mainten and low to power consumption. As the conparison, the observation quality of downhole tiltmeter is better than one in cave because it is not easy to be disturbed. Before many earthquakes there are medium and short term seismic precursor anomolies in data of the tiltmeters.

Abstract:Based on sorting out the M ≥ 5 earthquakes occurred in Ningxia and adjacent regions,the seismicity parameter anomalies before the medium-strong earthquake are synthetically analysed, and the synthetic prediction plan of earthquake(M ≥ 5)for one year scale in the region is made out.

Abstract:The methods of examination and analysis for earthquake-effect of dynamic-compaction to construction are presented, and the estimation of the effection on the adjacent building is obtained. It provids reference to designing of such construction.

Abstract:It is found after statistics that the styles of precursor anomaly of the atomosphetic pressure efficiency b-value of water level in well are different in Lu -0.3、04 wells to most earthquakes took place in North China and the adjacent regions. The analysis shows that the different combination patlerns of locating fault of wells and principal stress direction of seismic precursor field is the basical reason for it.

Abstract:The basic information of Lanzhou digital telemetry seismic network, several main technical problems, and running result are introduced. Some problems in network and advices for future are given. The experience for construction of Lanzhou network is useful to maintenance and enlarge construction of the network in future.

Abstract:The North Pacific Ocean closing to North pole region and the South Pacific Ocean openning to south pole region are the tectonic basis of El Nino. It makes thermal energy flow from North Pacific Ocean to South Pacific Ocean. Strong tide and volcano activities are the excitation condition of El Nino.

Abstract:The basic process and characters of the Chinese operation platform for earthquake rapid report in digital telemetry network are explicated. The program is writtern by using Vi edition method and Chinese characters are showed by 2-D coordinates lattice structure. The platform can connect automaticly with the program WaveView in software EDSP-IAS. The interface is direct to view, and is easy to operate, to determine seismic parameters and give result to inter-net and BP net.

Abstract:The precursor anomalies of ground resistivity, strain and crustal tilt in Wudu station,which locates near the boundary between Sichuan and Gansu province, before Kangding-Yajiang M_S 6.0 earthquake on Feb. 23, 2001 are introduced and analysised.

Abstract:2000年作者在进行黄河中上游河谷阶地考察时,在兰州刘家峡水库西侧祁家大坡公路边路堑壁上,发现一古象门齿化石.化石产出剖面位于黄河Ⅵ级阶地后缘,其海拔高度为1 880 m,拔河228 m.阶地为基座阶地,剖面描述如下:基座为前震旦纪变质岩系;上覆洪积砾石层,厚约5~10 m,向东延伸相变为黄河砾石层.洪积砾石层之上为3~4 m厚的冲积黄土,质地坚硬,强烈石膏化.

Abstract:2000年6月6日18时59分,甘肃省景泰发生了MS 5.9地震.经甘肃省监测台网测定,该次地震震中位于37.0°N,103.9°E,震源深度15 km.