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Acta Seismologica Sinica(English Edition) 1999年第1期12卷 55-62页

作者：黄立人马青郭良迁宋惠珍刘洁 The First crustal deformation monitoring center China Seismological Bureau Tianjin China Institute of Geology China Seismological Bureau Beijing China

A deformation monitoring network that covers part of North China area and takes the Beijing region as the center was measured for two times with high precision GPS in 1995 and 1996 respectively. The results from remeasurement indicate that present horizontal movement in the monitored area is characterized by relative motion among several main tectonic blocks. Considering the spatial distribution features obtained from geological survey and results on seismic wave and activity in the area, and stratified features of crustal medium in depth, a three dimensional finite element medium model is designed. And under the conditions of taking and not taking the action manner of the background stress field in the studied area into account, the relative motion between tectonic blocks is calculated and modeled. Based on the results from the analysis and calculations the dynamic mechanism for the present horizontal deformation in the area is discussed.

关键词： GPS measurement horizontal deformation three dimensional finite element

Preliminary　results　on　kinematic　model　of　tectonic　blocks　derived　from　high　precision　GPS　observations　in　Southwest　China

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Acta Seismologica Sinica(English Edition) 1997年第1期10卷 27-34页

作者：黄立人马青朱文耀程宗颐熊永清 First crustal deformation monitoring center State Seismological Bureau Tianjin China Shanghai Astronomical Observatory Chinese Academy of Science Shanghai China

In the paper, the kinematic model of tectonic blocks in southwest China is studied based on the precision GPS observations carried out under the major subject of 'Studies on Current crustal Movement and Geodynamics' which belongs to the State Climbing Project. It is believed that at present, the data of high precision GPS observation may provide convincing information related to the horizontal movement of tectonic blocks in the Chinese mainland. The preliminary results obtained from the kinematic model have given some direct evidences for the research of dynamic mechanism of crustal deformation in the Chinese mainland and on the basis of which, the kinematic characteristics and their relations to the seismicity and seismic risk in the reobserved region are analysed. The preliminary observation results are encouraging.

关键词： GPS observation Southwest China tectonic block kinematic model

Study of the Gravity Changes before and after the Jingtai M_S5.9 Earthquake

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Earthquake Research in China 2002年第2期16卷 127-137页

作者： Zhu Yiqing, Chen Bing, Zhang Xi and Zhang Sixin The second crustal deformation monitoring Centre, CSB, Xi’an 710054, China The second crustal deformation monitoring Centre CSBXi'an 710054China

By systematically analyzing the data of gravity reiteration in the Hexi region and taking a dynamic viewpoint, we have studied the evolution characters of gravity field during the preparation-occurrence of the Jingtai M S5.9 earthquake of June 6, 2000. The patterns of dynamic change of the gravity field clearly reflected how the gravity field evolved from the quasi-homogeneous state to non-homogeneous state for earthquake preparation and then the earthquake occurred. Besides, we have also studied the relation between the characteristic gravity change and strong earthquake activity.

关键词： Gravity field evolution Jingtai earthquake Earthquake prediction Characteristic gravity change

The newest observational evidence on asymmetrical deformation of the Earth

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Acta Seismologica Sinica(English Edition) 2002年第2期15卷 210-213页

作者：黄立人马宗晋朱建新 First crustal deformation monitoring center China Seismological Bureau Tianjin 300180 China Institute of Geology China Seismological Bureau Beijing 100029 China Department of Mathematics Zhejiang University Hangzhou 310013 China

Based on the coordinates, velocities and their error estimations of 595 GPS, SLR and VLBI stations issued by IERS in March 2001, the current asymmetrical deformation of the Earth is studied. The results show that the northern hemisphere of the Earth is undergoing compressive deformation, and the southern hemisphere is undergoing extensional deformation with the equator as the boundary. If the longitude line of 90°E and 90°W is taken as the boundary, the Pacific hemisphere (with 180° as its central longitude) is undergoing compressive deformation, and the Atlantic hemisphere (with 0° as its central longitude) is undergoing extensional deformation. The deformation patterns indicate again that the Earth is undergoing some dual-asymmetrical deformation. Moreover, taking 6 366.740 km as the standard mean curvature radius of the Earth, the velocity of volume change calculated from the data of space geodesy is 6.65x10-(11)m3/a.

关键词： asymmetrical deformation Earth space geodesy

Preliminary Study on the Horizontal crustal deformation in Chinese Continent

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Earthquake Research in China 2000年第4期14卷 21-31页

作者： Guo LiangqianFirst crustal deformation monitoring center, CSB, Tianjin 300180. China First crustal deformation monitoring center CSB Tianjin 300180 China

In the paper, the current strain field and stress field in Chinese continent have been discussedbased on the processed data from two GPS campaigns of national GPS network carried out inthe years of 1994 and 1996. With a principal compressional strain direction of NNE, thewestern and castern parts of Qinghai-Xizang subplate are dominated by extensional straiu andthe central Part by compressional strain. Along the southwestern segment of southeastern partof Qinghai-Xizang subplate, i. e. Yunnan area, the princiPal compressional strain direction isNW and the compressional strain is equivalent to the extensional strain in magnitude. Theprincipal compressional strain of Xinjiang subplate is mainly NNE and NE with a difference inthe strain magnitude. The principal compressional strain in North China subplate is quite effective in NE and nearly EW directions with differences along some segments. However, thecompressional strain is corresponding to the extensional strain in magnitude in most areas.

关键词： Horizontal deformation GPS crustal strain field

Study on the Horizontal deformation Strain Field in the Central and Northern Parts of Yunnan Province

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Earthquake Research in China 2003年第1期17卷 14-21页

作者： Li Yanxing, Guo Liangqian and Zhang ZhongfuFirst crustal deformation monitoring center, CSB, Tianjin 300180, China First crustal deformation monitoring center CSB Tianjin 300180 China

Based on the horizontal deformation field and the strain field derived from the GPS data over the period of 1999～2001 in the Yunnan area, the characteristics of deformation and strain in the northern part of Yunnan Province have been studied. The results indicate that the central part of the studied area is rather stable with little crustal displacement, while the western and eastern parts are active with larger displacement. The strain field reveals that the orientations of the principal compressive strain axis of the crust and the sub blocks in the area are NW SE, while the orientations of the principal tensile strain axis is NE SW. In the studied area, the tensile strain is predominatly in the northern part and the compressive strain is predominatly in the central and southern parts. The stretching direction of the shear strain contour is basically consistent with the strike of the active fault. The strain and stress fields of the fault activity are related to the structure where the fault is located, while the activity properties of the faults are different.

关键词： GPS deformation field Strain field

Temporal and spatial variation characteristics of present stress field in the northern area of North China

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Earthquake Science 2008年第6期21卷 573-584+673页

作者：李瑞莎崔效锋刁桂苓张红艳 Institute of crustal Dynamics China Earthquake Administration second Crust monitoring and Application center China Earthquake Administration Earthquake Administration of Hebei Province

From focal mechanism solutions of the earthquakes in the northern part of North China during the period of 2002～2006,the directions of principal stress axes in 4 stress sub-districts are analyzed using a grid test *** characteristic of present crustal stress directions is *** on this result and on the focal mechanism solutions calculated for some events in the period of 1977～1998,in combination with some other study results,the temporal variation of present crustal stress directions in the northern part of North China is *** re-sults confirm that the direction of crustal principal stress in some regions had somewhat rotated after the 1976 Tangshan M7.8 *** mean P axes of the focal mechanism solutions rotated clockwise not only in Tangshan sub-district,but also in Beijing and Xingtai sub-districts after the Tangshan *** Beijing and Xingtai sub-districts the orientations of principal stress axes in the period of 2002～2006 are consistent with that before the Tangshan earthquake,implying that the stress orientations has rotated back to the state before the Tang-shan earthquake in these two *** directions of the mean P axes are nearly E-W in Tangshan sub-dis-trict since the M7.8 *** present stress field in the sub-district northwest to Beijing,or in the western part of the Zhangjiakou-Bohai fault zone,is relatively stable during the time period concerned in this *** of the limitation of data,this paper only states a possible variation of stress field in the northern part of North China in the recent decades.

关键词： focal mechanism North China stress field

Experiment of Dividing the Active Blocks Based on Horizontal crustal Movement Observed by GPS

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Earthquake Research in China 2000年第4期14卷 32-37页

作者： Li Yanxing, Hu Xinkang, Shuai Ping and Guo LiangqianFirst crustal deformation monitoring center, CSB, Tianjin 300180, China First crustal deformation monitoring center CSB Tianjin 300180 China

In this paper, the discrepancy between the movements of intraplate blocks and plates isdiscussed, and the method to divide the intraplate active blocks is presented by selecting Bursaformula as the kinematic model for the intraplate blocks. Based on the data of three GPScampaigns in North-China network in l995, 1996 and l999, respectively, the northern area inNorth China is divided into eight small blocks with the mathematical model and methodpresented in this paper. The divided blocks based on tbe horizontal and vertical crustalmovements in the paper are consistent or approximate with each other in the area as a *** divided blocks in the paper is also basically accordant with the neotectonic movement,which indicates that the current movement of active blocks in this area is the succession anddevelopment of neotectonic movement. Moreover, some new activity characteristics in the areahave been revealed by the tectonic units divided with the horizontal crustal movement.

关键词： Horizontal movement Mathematical model Block division

Study on Evolution of Gravity Fieldand Earthquake Prediction in theNorth-south Seismic Belt and theEastern Qinghai-Xizang Block

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Earthquake Research in China 2001年第3期15卷 266-281页

作者： Zhu Yiqing,Jiang Zaisen and Chen Bing,Li Hui, Sun Shaoan,and Xiang Aimingsecond crustal deformation monitoring center, CSB, Xi’an 710054, China Institute of Seismology, CSB, Wuhan 430071, China second crustal deformation monitoring center CSB Xi' an 710054 China Institute of Seismology CSB Wuhan 430071 China

The relation between the dynamic evolution feature of gravity field and strong seismicity is studied. The result shows that the regional gravity field variation enjoys inhomogeneity of spatial and temporal distribution and gravity change in different regions. It may be resulted from active faults and seismogenic process, and may be due to microdynamic activity of regional strain energy, which might be accumulated or released in different stages, and there exists transformation process of stress.

关键词： North-south China seismic belt Gravity field evolution Seismicity

crustal movement and deformation in Taiwan and its coastal area

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Acta Seismologica Sinica(English Edition) 2002年第5期15卷 510-518页

作者：李延兴胡新康李智耿洪郭良迁郭逢英史粦华林继华丁学仁刘序俨张中伏 First crustal deformation monitoring center China Seismological Bureau Tianjin 300180 China Seismological Bureau of Fujian Province Fuzhou 350003 China

Based on the station velocity data obtained from Fujian coastal GPS network and Taiwan-Luzon GPS network and the data obtained from IGS permanent stations commonly used in the data processing of both networks, the uniformity of reference frames and velocity fields of both GPS networks is realized. It has been discovered from the analysis on the velocity field in Taiwan and its coastal areas that the horizontal crustal movements in the coastal area of Fujian, Taiwan Strait and the northern part of Taiwan Island are fully consistent. The movement direction is around 26.0E by S and the rate is about 39 mm/a. The opposite variation occurs in the coastal mountain area in the eastern part of Taiwan Island with the movement direction of 30.0N by W and the movement rate of about 33.3 mm/a. In the southern end of Taiwan Island, the movement direction is 50.0S by W and the movement rate is about 13 mm/a. If the geometric center of Fujian coast is used as the reference datum, Taiwan Island has a consistent (except its north end) NW-trending movement with the direction of around 50.0N by W. The maximum rate of 61 mm/a occurs along the eastern coast and decreases gradually towards west. The analysis of strain field indicates that Taiwan and its coastal area have a uniform strain field with the principal compressive strain direction of N48.0W and the principal tensile strain direction of N42.0E. The principal compressive strain rate along the eastern coast of Taiwan Island is 3.43610-7/a, which decreases gradually towards west and reaches 1.86110-8/a to Fujian coast. The collision and underthrust of Philippine Sea plate with Eurasian plate in the eastern part of Taiwan Island can be considered as the principal force for the crustal movement, deformation and great earthquake occurred in Taiwan and its coastal area. The direction of principal compressive stress in the area is about N55.0W.

关键词： unified frame analysis of velocity field analysis of strain field study of dynamics