地球物理学进展 ›› 2017, Vol. 32 ›› Issue (6): 2394-2400.doi: 10.6038/pg20170614

• 空间与固体地球物理 • 上一篇    下一篇

尼泊尔MW 7.9地震同震及震后地表形变及重力变化模拟

杨九元1, 张永志1, 祝意青2, 姜永涛3, 杨珍1, 徐云马2   

  1. 1. 长安大学地质工程与测绘学院, 西安 710054;
    2. 中国地震局第二监测中心, 西安 710054;
    3. 南阳师范学校环境科学与旅游学院, 河南南阳 473061
  • 收稿日期:2017-04-22 修回日期:2017-10-12 出版日期:2017-12-20 发布日期:2017-12-20
  • 作者简介:杨九元,男,1990年生,硕士生,主要研究方向为地壳形变与地球动力学.(E-mail:291813306@qq.com)
  • 基金资助:

    国家自然科学基金项目(41374028,61627824,41274083,41374026)和南阳师范学院博士专项基金(ZX2016007)联合资助.

Simulation of co-seismic and post-seismic surface deformation and gravity changes of Nepal MW 7.9 earthquake

YANG Jiu-yuan1, ZHANG Yong-zhi1, ZHU Yi-qing2, JIANG Yong-tao3, YANG Zhen1, XU Yun-ma2   

  1. 1. School of Geology Engineering and Geomatics, Chang'an University, Xi'an 710054, China;
    2. Second Crust Monitoring and Application Center, China Earthquake Administration, Xi'an 710054, China;
    3. School of Environment Science and Tourism, Nanyang Normal University, Henan Nanyang 473061, China
  • Received:2017-04-22 Revised:2017-10-12 Online:2017-12-20 Published:2017-12-20

摘要:

基于USGS公布滑动分布模型,本文利用用地壳分层模型,考虑到自重及黏弹特性,采用数值模拟的方法,对尼泊尔MW 7.9大地震同震及黏弹松弛效应引起的震后形变场及重力变化进行模拟计算,并与发震断层地表投影面附近区域实测同震GPS水平形变数据对比,结果显示:(1)同震形变场及重力变化均显示该次地震主要表现为逆冲型,且主要形变及重力变化主要发生在发震断层地表投影区域,离断层越远区域,形变量及重力变化值越小;(2)震后形变量及重力变化均增大,且影响范围逐渐增大,其中,垂直形变变化趋势与重力变化相反,表明地表高程变化与重力变化具密切的联系;(3)模拟同震结果与实测同震水平形变结果比较符合,少数台站点差异较大,但运动趋势与实测结果基本一致,一定程度上验证了模拟同震及震后形变量及重力变化的可靠性.

Abstract:

Based on the sliding distribution model provided by the USGS, this paperuses the earth's crust layered model and the method of numerical simulation, considering the gravity and sticky elastic characteristics, to calculatethe co-seismic deformation field and the gravity change and the post-seismic deformation field and the gravity change, then, this paper compares the co-seismic deformation with theco-seismic GPS date,Result show:(1) Co-seismic deformation field and gravity change shows that the earthquake belongs to thrust type, and the main deformation and gravity change occurs mainly in the seismogenic fault surface projection region, the farther from the fault zone, the smaller form variables and gravity change value; (2) The post-seismic deformation and gravity change all increase, and the influence range is increased gradually; Among them, the vertical deformation trend is the opposite of gravity change trend, it show that the surface height and gravity changes have close connection;(3)The simulation co-seismic results are in good agreement with the measured co-seismic deformation results, a few sites are different, but the trend of movement and the measured results are basically identical, it partly verifies the reliability of the co-seismic and post-seismic deformation field and the gravity change by the simulation calculation.

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