青藏高原东北缘重力变化机理研究  

STUDY ON MECHANISM OF GRAVITY FIELD CHANGE IN NORTHEASTERN MARGIN OF QINGHAI-TIBET PEATEAU

作　　者：祝意青[1] 梁伟锋[1] 陈石[2] 赵云峰[1] 

机构地区：[1]中国地震局第二监测中心,西安710054 [2]中国地震局地球物理研究所,北京100081

出　　处：《大地测量与地球动力学》2012年第3期1-6,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(40874035);国家科技支撑计划课题(2012BAK19B01)

摘　　要：通过对青藏高原东北缘重力观测资料进行整体平差计算,系统分析了该区1993—2003年的重力场变化特征;发现其与活动断裂构造密切相关。同时,利用重力与水准资料计算研究了青藏高原东北缘同期单层密度时变图像特征,得出区内地震活动与地壳密度变化的局部异常、高梯度带和等值线的拐弯有关;再利用青藏高原东北缘的区域布格重力异常及人工地震剖面信息,反演了Moho面分布特征,及在此基础上研究了地壳密度变形和位移对地表重力变化的影响,并对青藏高原东北缘区域微重力长期变化与布格重力异常空间相关性作出解释。Through whole Tibet plateau, the gravity field adjustment calculation of the gravity observations of the northeastern edge of Qinghai- variation characteristics in 1993 -2003 are analyzed systematically. It is found that significant gravity changes appeared to be concentrated in regions with active faults. By using the calculated results of gravity and leveling data, the characteristics of single layer density time -varying image during 1993 -2003 of the northeast edge of Qinghai-Tibet plateau are studied and it can be recognized that the seismic activity is related with the partial anomaly and high gradient of the variations of crustal density and the bending of its isoline. On the basis of the regional Bouguer gravity anomalies of northeastern edge of Qinghai-Tibet plateau and artificial seismic profile information, the distribution characteristics of Moho surface are inversed. Further more, the density deforma- tion of crust and the influence of the displacement on the gravity spatial correlation between regional microgravity long-term change edge of Qinghai-Tibet plateau are explained. change of the earth surface is studied as well. The and Bouguer gravity anomalies of the northeastern

关 键 词：青藏高原东北缘 重力 水准 密度变化 布格重力 莫霍面 

分 类 号：P315.726[天文地球—地震学]