地震工程学报Issue(2)：353-359,7.DOI:10.3969/j.issn.1000-0844.2014.02.0353
基于卫星重力的青藏高原东缘多尺度时变重力场研究
Study on Multi-scale Temporal Gravity Field in the Eastern Margin of Tibetan Plateau Based on Satellite Gravity
摘要
Abstract
In this paper,we calculate annual satellite gravity changes in the eastern margin of the Tibetan Plateau from 2003 to 2012 by using the Gravity Recovery and Climate Experiment (GRACE)time-variable gravity field models with decorrelated filtering.By contraposing the three strong earthquakes that occurred recently in this region,including the Wenchuan MS8.0,Yushu MS 7.1,and Ya’an MS 7.0 earthquakes,we analyze the changes in satellite gravity field features re-lated to the strong earthquakes with the annual gravity changes before and after each earthquake. For analyzing the relationship between these earthquakes and the gravity change mode in detail, we also caculate the monthly gravity change for the Wenchuan MS 8.0 and Yushu MS 7.1 earth-quakes.Moreover,we use the recently relesed weekly GRACE gravity models to caculate the point-wise gravity change near Longmenshan fault for the Wenchuan MS 8.0 earthquake.The re-gional annual differentiated dynamic gravity changes image indicates that all three earthquakes oc-curred in a period of small gravity change,which means a small migration of crust-mantle material occurred according to the mantle convection theory.The same feature is indicated in the regional annual cumulative dynamic gravity changes image.These gravity changes likely indicate a medi-um-short term earthquake precursor.In the monthly differentiated dynamic gravity changes im-age,the gravity change mode shows significant changes in both the Wenchuan MS 8.0 earthquake and the Yushu MS 7.1 earthquake,which indicates that the gravity gradient change direction al-tered from perpendicular to the plane of a fault to parallel.These change in the gravity change mode may confirm the theory of post-earthquake potential field restoration.The nine points of the weekly gravity change sequences in Longmenshan fault area that occurred during 2008 indicate that a nearly nine-week contrary gravity change trend occurred between the eastern and western areas of the fault after the occurrence of the Wenchuan MS 8.0 earthquake.These gravity mode changes may be the reflection of an adjustment procedure of the crust-mantle material after the earthquake.Gravity measurement is an important subject in earthquake prediction research.Satel-lite temporal gravity analysis greatly enriches and complements the deficiency of the ground gravi-ty network in time and space scales and can be quickly used for the study of crustal movement and earthquake prediction.关键词
青藏高原东缘/地震/GRACE/滤波/重力变化Key words
the eastern margin of the Tibetan Plateau/earthquake/GRACE/filtering/gravity change分类
天文与地球科学引用本文复制引用
姜永涛,张永志,王帅,刘国仕..基于卫星重力的青藏高原东缘多尺度时变重力场研究[J].地震工程学报,2014,(2):353-359,7.基金项目
国家自然科学基金（41374028；41274083）；地震行业科研专项 （）
