地球物理学进展 ›› 2019, Vol. 34 ›› Issue (5): 1750-1756.doi: 10.6038/pg2019CC0431

• 固体地球物理及空间物理学(大气、行星、地球动力学、重磁电及地震学、地热学) • 上一篇    下一篇

利用GRACE数据反演日本MW 9.0地震区域黏滞性

高阳1,张永志1,*(),尹文浩2   

  1. 1. 长安大学地质工程与测绘学院,西安 710054
    2. 西安市勘查测绘院,西安 710054
  • 收稿日期:2018-11-25 修回日期:2019-06-12 出版日期:2019-10-28 发布日期:2019-10-28
  • 通讯作者: 张永志 E-mail:971148291@qq.com
  • 作者简介:高阳, 女, 1989年生,博士生,主要研究方向为InSAR、重力和地壳形变.(E-mail: 184088137@qq.com)
  • 基金资助:
    国家自然科学基金资助(41374028)

Viscosity of the Japan MW 9.0 earthquake inferred from GRACE RL05 data

GAO Yang1,ZHANG Yong-zhi1,*(),YIN Wen-hao2   

  1. 1. School of Geology Engineering and Geomatics, Chang’an University, Xi’an 710054, China;
    2. Xi’an Institute of Surveying and Mapping, Xi’an 710054, China;
  • Received:2018-11-25 Revised:2019-06-12 Online:2019-10-28 Published:2019-10-28
  • Contact: Yong-zhi ZHANG E-mail:971148291@qq.com

摘要:

利用CSR(Center for Space Research)发布的GRACE RL05月重力场模型数据,通过水文模型GLDAS(Global Land Data Assimilation System)和CPC(Climate Prediction Center)扣除土壤水和雪水的影响,根据冰川模型扣除GIA(Global Isostatic Adjustment)的影响,采用P3M6去相关滤波和300 km扇形滤波,基于最小二乘拟合的方法得到日本MW 9.0地震的同震及断层上下盘两个特征点重力变化时间序列,利用PSGRN/PSCMP模型对日本MW 9.0地震区域黏滞性进行了反演,并计算了同震及震后5年研究区域重力变化的空间分布.结果表明,扣除土壤水和冰川均衡调整因素的影响,同震重力变化为-5.2×10 -8~2.9×10 -8 ms -2;两个特征点在震后5年重力均增加,下盘重力增加较大;日本MW 9.0地震区域黏滞性横向差异较明显,断层上下盘的地幔黏滞系数分别为2.5×10 18 Pa·s、5.0×10 17 Pa·s时,与GRACE观测值较接近,综合考虑断层上下盘的震后重力变化,区域黏滞系数大约为1.5×10 18 Pa·s.

关键词: GRACE, 黏滞性, 日本MW 9.0地震, 重力变化

Abstract:

Based on the RL05 monthly gravity field model released by CSR, the soil moisture and snow water is deducted from the global hydrological models GLDAS (Global Land Data Assimilation System) and CPC (Climate Prediction Center),the GIA (Global Isostatic Adjustment) effect is deducted from the glacier model as well,the co-seismic gravity change of the Japan MW 9.0 earthquake is successfully obtained by using the method of least squares fitting with the strategy of P3M6 decorrelation filter 300km fan filter. The time series of gravity change at two points on on the hanging side and the heading side are analyzed as well by using the same method,respectively. The viscosity of the Japan MW 9.0 earthquake is inferred by using PSGRN/PSCMP, the co-seismic and post-seismic gravity change in the study area is calculated as well. The results show that, the co-seismic gravity change in the study area is -5.2×10 -8~2.9×10 -8 ms -2 after deducting the effect of soil moisture and GIA; the gravity increase is obvious at the two characteristic points,the point on the hanging side located in the Pacific Ocean increase more significant;the difference of the viscosity is obvious on the heading side and the hanging side,when the viscosity of the hanging side and the heading side is 2.5×10 18 Pa·s, 5.0×10 17 Pa·s, respectively, the results agree well with which calculated from Gravity Recovery and Climate Experiment(GRACE)data,considering the post-seismic gravity change of the two sides, the regional viscosity coefficient is about 1.5×10 18 Pa·s.

Key words: Gravity Recovery and Climate Experiment(GRACE), Viscosity, Japan MW 9.0 Earthquake, Gravity changes

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