用GPS测量结果研究华北现今构造形变场  

STUDY ON PRESENT-DAY DEFORMATION AND STRAIN FIELD IN NORTH CHINA BY USE OF GPS DATA

作　　者：张静华[1] 李延兴[1] 郭良迁[1] 张中伏[1] 

机构地区：[1]中国地震局第一监测中心,天津300180

出　　处：《大地测量与地球动力学》2004年第3期40-46,共7页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金 (4 0 1742 0 9);中国地震局第一监测中心人才培养基金

摘　　要：用华北及邻区近十多年GPS测量结果和欧亚板块的弹性运动模型研究华北地区的水平形变场和局部水平形变场 ,发现华北地区水平形变场存在比较一致的SE向运动 ,且运动方向绕顺时针方向逐渐旋转 ,从西向东运动速率逐渐增大。鄂尔多斯、华北平原和鲁东 黄海地块的运动速率分别为 4 .8mm/a、5 .0mm/a、5 .2mm/a ,运动方向分别为SE5 0°、4 0°、35°。鄂尔多斯、华北平原和鲁东 黄海地块的局部形变方向分别为SE方向、SSE方向和SSW方向 ,而华北局部形变场的形变速率大约为水平形变场的 5 0 %。应用地块的整体旋转与线性应变模型计算了华北主要断裂带两侧的相对运动和各地块内部的主应变场。华北EW向和NWW向断裂基本上为左旋走滑型 ,滑动速率从东向西逐渐减小 ;NNE向和NE向断裂基本上为右旋走滑型 ,从北向南滑动速率逐渐减小。华北地区应变场的基本格架是NEE SWW方向压缩与NNW SSE方向扩张 ,主压应变率从西向东逐渐增大而主张应变率从西向东逐渐减小。根据全区水平形变场与应变场的基本特征推测 ,华北地区构造运动与形变的主要驱动力为 :青藏高原NE方向的推挤力 ,太平洋板块向欧亚板块俯冲对华北地壳产生的西向推挤力 ,以及地壳上隆所产生的NWBased on the GPS data of the North China and its adjacent areas surveyed in the past more than ten years and the elastic motion model of Eurasia plate, the horizontal deformation field and local horizontal deformation field in the North China area are obtained. The horizontal deformation field in the North China exhibits a rather consistent movement along the SE while the motion direction turns gradually with clockwise, and the movement rate raises from west to east.The motion rates of Ordos, North China plain and Eastern Shandong Huanghai blocks are 4.8 mm/a, 5.0 mm/a and 5.2 mm/a and their motion directions are SE50°, SE40° and SE35°respectively. Besides the deformation rate for local deformation field in the North China is about 50% of that of the horizontal deformation field.The local deformation directions of Ordos, North China plain and eastern Shandong-Huanghai blocks are SE, SSE and SSW, respectively. The relative motion on both sides of major fault zones and the principal strain field in each block are calculated by use of the model with rotation of entire block and linear strain. Basically, the EW and NWW trending faults in the North China are left lateral strike slip ones and the slip rates decrease from east to west,while the NNE and NE trending faults in the North China are right lateral strike slip ones and the slip rates decrease from north to south. The basic frame of strain field in the North China is that: the compression is NEE SWW directional and the extension NNW SSE directional and the principal compressive strain rate increases gradually from west to east and the principal tensile strain rate decreases gradually from west to east. It is inferred on the basis of general characteristics of horizontal deformation field and strain field in the whole area that the main driving forces of the tectonic movement and deformation in the North China are: the NE directional pushing force from Qinghai Tibit plateau, the west directional pushing force to the crust of the North Chin

关 键 词：GPS 速度场 构造形变 应变场 动力学分析 

分 类 号：P228.4[天文地球—大地测量学与测量工程] P54[天文地球—测绘科学与技术]