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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

Establishment of the GPS monitoring Network in North china, the Relation of Horizontal crustal Movement to Stress Field and Seismicity

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Earthquake Research in china 1998年第4期12卷 30-39页

作者： li yanxing, hu xinkang, Zhao Chengkun, Wang Min, guo liangqian, and Xu JushengFirst crustal deformation monitoring center, china Seismological Bureau, tianjin 300180, china Institute of Seismology, china Seismological Bureau, Wuhan 430071, china

In the paper, the establishment, measurement, data-processing program and monitoring accuracy of the GPS seismic monitoring network in North china, especially in the Capital-Circle area, have been presented briefly. The relation of horizontal crustal deformation to tectonic movement, stress-field variation and seismicity has been analyzed in detail. The results indicate that the accuracy of GPS measurement has reached the order of 10-9 and the annual rate of horizontal crustal deformation in North china is about 4 ~5 mm. Horizontal crustal movement is a direct indication of the regional stress field. Therefore, by monitoring the time-sequence variation of horizontal crustal motion, it would be possible to investigate the change in the stress field, to analyze the tendency of seismicity and to determine the seismogenic zones.

关键词： GPS network establishment Accuracy analysis Study of horizontal deformation field Tectonic movement.

基于GPS观测的地壳水平运动划分活动地块的试验

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中国地震 2000年第2期16卷 135-139页

作者：李延兴胡新康帅平郭良迁中国地震局第一地形变监测中心中国天津300180

本文分析了板内块体与板块运动的差别 ,提出以Bursa公式作为板内块体的运动学模型 ,并据此提出了划分板内活动地块的方法。根据华北GPS网 1995、1996和 1999年的 3期观测成果 ,用本文提出的数学模型和方法 ,将华北北部地区划分为 8个小... 详细信息

本文分析了板内块体与板块运动的差别 ,提出以Bursa公式作为板内块体的运动学模型 ,并据此提出了划分板内活动地块的方法。根据华北GPS网 1995、1996和 1999年的 3期观测成果 ,用本文提出的数学模型和方法 ,将华北北部地区划分为 8个小块体。本文用地壳水平运动划分的结果与用本区地壳垂直运动划分的结果在总体上是一致或相近的。本文的划分结果与新构造运动也基本一致 ,本区活动块体的现今运动是新构造运动的继承和发展。此外 ,用地壳水平运动划分的构造单元提示出本区一些新的活动特征。

关键词：水平运动数学模型块体划分 GPS 地壳

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宝坻-苗庄凸起新生断裂脆韧性转换深度研究

Applied Geophysics 2024年第1期21卷 188-202,206页

作者：李赫董一兵王熠熙高武平闫成国蔡玲玲吴博洋彭钊天津市地震局天津300201 河北经贸大学石家庄050061 中国科学院精密测量科学与技术创新研究院大地测量与地球动力学国家重点实验室武汉430077 河北省地震局石家庄050021

现今地震是最新构造活动的最直接表现,是认识大陆内部非刚性变形特征的最有力工具。尤其是对晚更新世以来开始活动的新生断裂来说,由于发育成熟度低,几何构造上贯通性差且不同区段走向/不同深度倾向差异明显,地震能够揭示其三维空间的变... 详细信息

现今地震是最新构造活动的最直接表现,是认识大陆内部非刚性变形特征的最有力工具。尤其是对晚更新世以来开始活动的新生断裂来说,由于发育成熟度低,几何构造上贯通性差且不同区段走向/不同深度倾向差异明显,地震能够揭示其三维空间的变化,尤其是脆韧性转换深度特征,促进对新生活动断裂孕育、发震过程的认识。渤海湾盆地新生走滑活动断裂曾多次发生强震,如唐山M_(S)7.8、三次宁河M_(S)≥6.2地震,这些地震揭示的地壳脆-韧性转换深度对认识该地区地震发震机理和活动性具有重要的现实意义。本文以渤海湾盆地内宝坻-苗庄凸起新生断裂为目标断裂,以发生于宝坻凸起的2012年宝坻M_(S)4.0、M_(S)3.5地震以及发生于苗庄凸起的1976年宁河M_(S)6.2、M_(S)6.9、1977年宁河M_(S)6.2地震为研究对象,基于首都圈数字地震台网的波形资料,采用CAP方法研究宝坻M_(S)4.0、M_(S)3.5地震震源机制解和震源深度,利用近震转换波Sp精确确定震源深度,采用双差方法定位两个地震序列的震源位置,并结合其他资料探讨该地区地震的发震机理以及新生断裂脆韧性转换深度。结果显示:(1)宝坻M_(S)4.0、M_(S)3.5地震震源性质与宝坻-苗庄凸起出露地表的已知断裂不尽相符,结合宁河三次MS≥6.2地震震源参数的有关研究成果,推测它们均发震于宝坻-宁河深大断裂;(2)结合震源区电性结构以及流变结构等模型,宝坻-苗庄凸起这五次显著地震揭示出宝坻-宁河深大断裂的脆韧性转换深度为15km左右;(3)结合渤海湾盆地动力演化过程以及深部地球物理探测等相关资料,推测该地区地震活动主要是宝坻-宁河深大断裂与深部流体作用的结果。

关键词：新生断裂渤海湾盆地宝坻-苗庄凸起宝坻-宁河深大断裂脆韧性转换深度

Movement and strain conditions of active blocks in the Chinese mainland

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Science china Earth Sciences 2003年第z2期46卷 82-117页

作者： li yanxing (李延兴) YANG guohua (杨国华) li Zhi (李智) guo liangqian (郭良迁) huANG Cheng (黄珹) Zhu Wenyao (朱文耀) FU Yang (符养) WANG Qi (王琪) JIANG Zaisen (江在森) WANG Min (王敏) First crustal deformation monitoring center China Seismological Bureau Tianjin 300180 China First Crustal Deformation Monitoring Center China Seismological Bureau Tianjin 300180 China First Crustal Deformation Monitoring Center China Seismological Bureau Tianjin 300180 China First Crustal Deformation Monitoring Center China Seismological Bureau Tianjin 300180 China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Institute of Seismology China Seismological Bureau Wuhan 430071 China Center for Earthquake Analysis and Prediction China Seismological Bureau Beijing 100036 China Center for Earthquake Analysis and Prediction China Seismological Bureau Beijing 100036 China

The definition of active block is given from the angles of crustal deformation and strain. The movement and strain parameters of active blocks are estimated according to the unified velocity field composed of the velocities at 1598 GPS stations obtained from GPS measurements carried out in the past years in the Chinese mainland and the surrounding areas. The movement and strain conditions of the blocks are analyzed. The active blocks in the Chinese mainland have a consistent E-trending movement component, but its N and S components are not consistent. The blocks in the western part have a consistent N-trending movement and the blocks in the eastern part have a consistent S-trending movement. In the area to the east of 90°E, that is the area from Himalayas block towards NE, the movement direction of the blocks rotates clockwisely and the movement rates of the blocks are different. Generally, the movement rate is large in the west and south and small in the east and north with a difference of 3 to 4 times between the rates in the west and east. The distributions of principal compressive strain directions of the blocks are also different. The principal strain of the blocks located to the west of 90oE is basically in the SN direction, the principal compressive strain of the blocks in the northeastern part of Qingzang plateau is roughly in the NE direction and the direction of principal compressive strain of the blocks in the southeastern part of Qingzang plateau rounds clockwisely the east end of Himalayas structure. In addition, the principal strain and shear strain rates of the blocks are also different. The Himalayas and Tianshan blocks have the largest principal compressive strain and the maximum shear strain rate. Then, Lhasa, Qiangtang, Southwest Yunnan (SW Yunnan), Qilian and Sichuan-Yunan (Chuan-Dian) blocks followed. The strain rate of the blocks in the eastern part is smaller. The estimation based on the stain condition indicates that Himalayas block is still

关键词： active block, movement condition, strain condition.