摘要
本文利用我国三十多年来积累的近三十万公里精密水准复测资料，研究了我国近期垂直陆地运动的主要特征，即：（１）我国陆地构造性垂直运动的主要特征为＂南升北降＂、＂东弱西强＂；并且与地形地貌具有一定的相关性，表现为清晰的继承运动性质，从运动量值及等值线的展布方向来看，我国大陆明显地受印度板块和太平洋板块的控制，以印度板块的作用为最强烈；（２）内陆地区中强地震（Ｍｓ≥６．０）以上的地震形变的主要特征为：地震形变半径大（＞６００ｋｍ），范围广，震源地区形变图象特殊，而且形变值较大，为正常量值的数倍。随着距震中距离的增大，其形变强度也逐步减弱，地震前后的形变在地震形变区域范围内均具有明显的弹性回跳特征，在震源区内也存在一定的剩余形变；（３）经济发达地区的地面沉降及形变日趋严重，现为十几毫米／年～几十毫米／年，由过去的点发展成面，又连成片。尤其是我国东部的沿海地区，沉降漏斗已连成网，地面标高日渐损失，现已表现为一种明显的灾害源或潜在灾害源。这种地面沉降的产生是由于过量开采地下水所致，其运动特点为下沉而不可逆，即使不过量开采地下水，也只能控制沉降而难以使其显效回升。
Main features of recent vertical land movement in China are studied based on the precise releveling data with about 300,00km over China Mainland,which has been accumulated for more than 30 years.The following conclusions are obtained.(1) Tectonic vertical movments of China Mainland are shown as uplifting in the south and subsiding in the north,strong in the west and weak in the east, these movements are apparently constrained by the Indian and the Pacific plates,the former plays a dominant role.(2) Main features of deformation on intraplate strong earthquake Ms≥6.0 are larger radius of the crustal deformation anomaly(>600km),larger value of deformation anomaly(several times～over ten times),the four-quadrantal distribution in the source areas often,obvious elastic rebound over the whole area of deformation anomaly and residual deformation in the source area after earthquake.(3) earth-surface subsidence is large up to several tens mm/a in developing economic area of China because of over-pumping underground water and the subsidence scope has been increasing.Especialy in the coastal area of China,the surface deformation is more heavy and the height of the surface is losing.So that they have resulted in huge ecomonic loss.In general,this kind of the movement might not back-lift effectly even though the underground water is not pumed i.e.it is only controlled by decreasing the use volume of the underground water but is not back-lifted.
出处
《中国地质灾害与防治学报》
CSCD
1996年第2期37-43,共7页
The Chinese Journal of Geological Hazard and Control
基金
地震科学基金
关键词
中国
大陆
地震
垂直形变
地面沉降
陆地运动
China mainland,vertical crustal movement,earthquake verticaldeformation,earth subsidence
