GRACE卫星观测到的尼泊尔8.1级地震前后的重力变化

发布时间：2018-04-10 04:16

  本文选题：GRACE　切入点：尼泊尔地震　出处：《大地测量与地球动力学》2017年12期

【摘要】：利用GRACE卫星重力资料,计算尼泊尔地震震中及周缘重力和地表密度时空变化,并获取震源域特征点重力变化时间序列。结果表明,青藏高原内部、印度北部及华南块体东侧重力以增加为主,喜马拉雅与缅甸弧形带重力呈逐年减少趋势;尼泊尔地震发生在正负重力变化梯度带上,且重力变化在2015年具有明显的时间分段性特征,1~3月及地震发生的4月重力均以减小为主,5~9月以增加为主,12月以后以减小为主逐渐恢复;特征点时序揭示震源域重力呈长期减少趋势,并在2013~2016年呈现出"增加-减少-增加-发震-减小"的变化特征;地表密度变化较好地反映出地表质量迁移与重力变化的关系,为进一步理解尼泊尔地震的大陆动力学机制提供参考。
[Abstract]:Based on the GRACE satellite gravity data, the temporal and spatial variations of gravity and surface density in and around the Nepal earthquake are calculated, and the time series of gravity variation at characteristic points in the source region are obtained.The results show that the gravity of northern India and southern China blocks increases mainly in the Qinghai-Tibet Plateau, the gravity of the Himalayan and Myanmar arc belts decreases year by year, and the Nepal earthquake occurs in the gradient zone of positive and negative gravity variation.The gravimetric variation in 2015 has obvious time segmental characteristics: gravity decreases mainly from May to September and gradually recovers from December after the earthquake occurred in April and decreases mainly from May to September.The time series of feature points reveal a long-term decreasing trend of gravity in the focal region, and the variation characteristics of "increase-decrease-increase-increase-seismogenic-decrease" in 2013 ~ 2016, and the change of surface density reflects the relationship between surface mass migration and gravity change.It provides a reference for further understanding the continental dynamic mechanism of the Nepal earthquake.
【作者单位】： 长安大学地质工程与测绘学院;中国地震局第二监测中心;
【基金】：国家自然科学基金(41674001,41504005,41202189) 陕西省自然科学基础研究计划(2016JM4005) 中国博士后科学基金(2013M530412,2016M602741) 中国地震局地震行业科研专项(201208009) 中央高校基本科研业务费专项基金(310826172202)~~
【分类号】：P315.7
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本文编号：1729622