青藏高原东北缘现今构造变动与地震活动特征  

Characteristics of Recent Tectonic Deformation and Seismic Activity in the Northeastern Margin of Tibetan Plateau

作　　者：王双绪[1] 张希[1] 张四新[1] 张晓亮[1] 薛富平[1] 

机构地区：[1]中国地震局第二监测中心,陕西西安710054

出　　处：《地球学报》2005年第3期209-216,共8页Acta Geoscientica Sinica

基　　金：地震科学联合基金项目(编号:104011);中国地震局"十五"重点科研项目(编号:1005010504);国家重点基础研究项目"大陆强震机理与预测"(编号:G1998040703)共同资助。

摘　　要：笔者利用青藏高原东北缘20世纪70年代以来的精密水准网和跨断层流动形变网监测资料和近10a来高精度GPS观测结果,结合地质构造和地震活动,研究和探讨了该区现今构造变动和强震活动的一些特征和初步机理。结果表明:①研究区现今构造变动具有空间分布的不均一性和随时间演化的非平稳性,其总体趋势呈现为新构造时期以来的继承性;②构造变动过程中的快速隆升异常区和与之相伴生的高梯度变形带、以及显著地断层活动异常,是较强地震孕育的标志,地震往往发生在具有较高应变积累的区域附近;③印度板块对青藏高原的强烈挤压是该区构造变动与地震活动的主动力环境;构造变动和地震与块体活动及区域构造应力场变化密切相关。Using observatory data of precise level networks and cross-fault mobile monitoring nets obtained since 1970′s as well as precise data observed by GPS in the past 10 years in the northeastern margin of Tibetan Plateau, combined with geological structure and seismic activities, the authors studied some features and preliminary mechanism of recent tectonic deformation and strong earthquake activities. Some conclusions have been reached: ① Recent tectonic deformation of this area shows spatial inhomogeneity and temporal unbalance, reflecting the general trend of inheritance since the new tectonic period. ② The abnormally quick uplifting region and its associated high-gradient deformation zone as well as obvious abnormality of fault activity are symbols of strong earthquakes, and earthquakes commonly take place in and near the region with high strain accumulation. ③ Violent compression of Indian Plate against Tibetan Plateau is the main dynamic environment for tectonic deformation and seismic activities of this area; tectonic deformation and earthquakes have close relationship to the evolution of regional tectonic strain field.

关 键 词：青藏高原东北缘 构造变动 地震活动特征 20世纪70年代 高精度GPS 应力场变化 观测结果 监测资料 地质构造 强震活动 非平稳性 时间演化 不均一性 空间分布 快速隆升 活动异常 地震孕育 应变积累 动力环境 印度板块 区域构造 

分 类 号：P618.130.2[天文地球—矿床学] TU459.4[天文地球—地质学]