Abstract:The data of thermal infrared remote sensing of Lanzhou receiving station from meteorological satellite on northern Tibet plateau(34°~38° N, 86°~94° E), in three month before Nov. 14, 2001 M_S 8.1 earthquake at Xinjiang-Qinghai border are calculated, analyzed and researched. The results shows that obvious belt anomaly of the earth's surface temperature appeared from on Oct. 17, 2001, the anomalous area became more large and with migration phenomena. The whole anomalous time kept on near one month.

Abstract:In order to recognize the seismic phases of a regional earthquake automatically, the algorithm of increasing waveform variation value and the criterion of no-subsequent-phase are put forward firstly. The former is to describe the waveform variation of a regional earthquake from its waveform variation value, for capturing the sudden variations of amplitude or frequency of seismic wave by using increase of its value.The latter is used to observe the variations of subsequent waveforms after determining the onset. If there are no other phases in the subsequent waveform, the recognition of onset is invalid. Using this criterion, it will not recognize subsequent phases with bigger amplitudes as the onset phase when the amplitude of the onset phase is too small to be recognized clearly. It shows by the example tests that the accuracy of the method meets the need of the prompt report of earthquake. The relevant programs are compiled.

Abstract:F-K analysis can be used in processing data of seismic array, and getting detailed information on seismic wave field. This approach can separate seismic signals which arrive the array almost at same moment, and identify the type of wave with different velocity. All those are helpful to distinguish complex seismic wave.Mainly the procedure of F-K analysis and application in Shanghai Seismic Array are discussed.

Abstract:Relationship between earthquake and the earth deformation field is studied based on the viewpoint of field analyses. Deformation fields are obtained by introducing a series of numerical calculation steps in processing ground tilt data. The results show that the methods are capable of making up the shortcomings of the lack of data. Some typical deformation states on the earth surface are well reflected by earth deformation field such as convex/concave areas. The field analyses method also provides a useful idea for how to get and utilize large-scale spatial-temporal information in earthquake observation and prediction.

Abstract:The northern margin fault zone of Maxian Mt. in Lanzhou area is a Holocene active fault which includes about 4 secondary fault segments. Along the active fault zone, several palaeoearthquake events are found in trench profiles. The activities of palaeo-earthquakes exist inhomogeneity in time and space. In the east, on Maxian Mt. segment, there are two events occurred in 5 850 ±500 a B. P., 2 060 ±420 a B. P., respectively. Their magnitudes are about 7~7. 5, the recurrence interval is about 3 800 a.In middle segment, Qidaoliang segment, two events are ditermined, in 16 820 ±80 a B. P., 10 800 ±10 a B. P., both are in Late Pleistocene.In west segment, Xianshui valley segment in northern margin of Wusu Mt., one palaeo-earthquake with age of 1 245 ±560 a B. P. is found. Considering the distribution of loess landslides and ancient town sites, this event is mostly the Lanzhou M 7 in 1125. According to the palaeo-earthquake ages and recurrence interval features, the strong earthquake hazard segments of the northern margin active fault zone of Maxian Mt. will be the east segment Maxian Mt. fault segment and the west segment Xianshui valley fault segment of Wusu Mt..

Abstract:Based on random Poisson distributional model and Gutenberg-Richter law, we made 8 groups of simulated seismic catalogues with the sample size of 1 000 to 15 000 within 20 years so that we could discuss the effect on the H value of frequency sequence of seismicity caused by the calculational conditions of sample size and τ_max of maximal fitting window length. The result shows that the whole precision and stability of H value improve with the sample size increasing. When τ_max is equal to 300, it is specially obvious. Case calculations show that it is available to pick up well the process of anomaly change of H value before strong earthquake with selecting reasonable calculational conditions.

Abstract:Cross-fault measurements data in 28 years of Heizi deformation station is studied by multinomial drafting、annual extremum difference、speed、fault relatively minim displacement analysis. The results indicats that annual variation aberrance、speed quicken、annual extremum difference exceeding and fault relatively minim displacement evidently increasing are abnormality characteristics of medium-strong earthquake in Heizi area (R=100 km).

Abstract:The applications of the LU RR(load/unload response ratio)to the prediction of some medium-strong earthquakes in northern Qinghai-Tibet plateau are cited as instances. Based on naturally occurring earthquake sequence, the effect of sample conditions on the results of LURR is discussed. Some matters of applying LURR to mid-short term prediction before an earthquake and to tendency analysis after an earthquake are also studied for raising its prediction corresponding ratio.

Abstract:After processing the data of geoelectric field and geomagnetic component from Tianzhu sino-France coorperate station in Oct. 1994 to Jun. 1997, with methods of mean value analysis, fractional dimension, vertical polarization direction projection and two-dimension inversion of fixed-set MT, it is found out that the 5 parameters in the 4 methods take on short-impending anormalies in different extent before Yongdeng M_S 5.8 earthquake (Δ=84 km)on July 22, 1995 and Tianzhu M_S 5.4 earthquake (Δ=65 km)on June 1, 1996. All these anormalies show good coordination, and the fractional dimension and principal-axis apparent resistivity anormalies show clear orientation. The anormalies of geoelectric field is more sensitive to the earthquake preparation process of Tianzhou event which took place on the same fault with the station. The anormaly reliability is discussed from 4 points and the anormaly possible mechanism is given. It is suggested that the geoelectric anormaly before Yongdeng M_S5.8 earthquake is produced mainly by the focus electromagnetic radiation, comline with electric property variation of medium under the station at depth of 7 km, while before Tianzhu M_S5.4 earthquake mainly by the resistivity variation of rock along the fault strike at depth of 5~30 km under the station.

Abstract:MT tensor descomposition method and its improvements are introduced,and more credible real regional structural strike be determined by decomposing the actually measured MT data using the iproved method.Combining the decomposition results,the response function such as apparent resistivite,phase,strike,skew et al.and dimensional weight parameter to make a comprehensive analysis,the more detailed information for the demensional parameter of structure can be obtained.The study of the actually measured MT data in Lanzhou area shows:in the area the regional conductivity structure is mainely two dimensional,and the strike is approximately in north-south or in west-east.

Abstract:To the multiple parameters comprehensive analysis method of MT earthquake precursor, it is useful to judge reliablely latest appearing MT precursor that fully using the information from every parameters, comprehensively studying and analyzing their variation with time. With practical data, the earthquake monitor efficiency and applied present situation on 6 MT response function are discussed.

Abstract:Based on the mechanism of artificial excavated belled pile foundation and the basic principle of waveform fitting method, features and practicability about the method applied to determing bearing capacity of the pile foundation are explicated in associated with several practical engineering examples.

Abstract:The "information system for emergence decision on the earthquake prevention and disaster reduction in Shanghai City" based on GIS technology is introduced. This information system consists of 7 functional modules. Mainly they are basic information of seismology and geology, subsystem of rapid evaluation for damage loss from earthquake, subsystem of decisive information for earthquake emergence, information query, maintenance and management of system, and etc., Meanwhile, the software application technology, such as color infrared aerophotograph, remote sensing and etc., and point out that the information system is needed to be improved in some aspects.

Abstract:Two monthes after the M_S 5.2 earthquake in Chengjiang on Nov. 25, 1999, M_S5.5 earthquake occured between Qiubei and Mile, where is nearby the Chengjiang, on Jan. 27, 2000. The regional seismicity background, the seismogenic progress of the earthquake and the anomaly characteristics of seismic activity are analyzed. A case for how to predict the follow-up earthquake after a medium-strong earthquake is provided.