基于GPS观测值研究日本M_W9.0地震震后形变机制

发布时间：2018-04-18 00:16

  本文选题：GPS观测 + 日本MW.地震　； 参考：《大地测量与地球动力学》2017年12期

【摘要】：基于GPS观测的震后水平位移对2011年日本MW9.0地震的震后形变特征进行研究。震后近5a(截至2015-12),震后水平位移累积达到东向60~165cm,南向20~65cm,距离震中较远处的G104、G105及J192站点观测到的震后位移累积变化已超过同震位移,且震后形变还在持续。联合震后余滑和粘弹性位错理论模拟震后形变,利用这2种作用机制对震后GPS水平形变进行解释。研究表明,震后余滑在震后形变最初阶段起主要作用,但随着时间增长而逐渐衰减,粘滞性松弛作用的贡献随着时间增长而变大,GPS观测到的震后地表形变可由这2种机制结合得到较合理的解释。利用震后GPS形变模拟估算地震区域的地幔粘滞系数在1.5×1019 Pa·s量级。
[Abstract]:Based on the horizontal displacement observed by GPS, the deformation characteristics of the 2011 MW9.0 earthquake in Japan were studied.After the earthquake, the accumulative horizontal displacement has reached 60,165cm in the east direction, 205cm in the south direction, and the accumulative variation of the post-earthquake displacement has exceeded that observed at the G104G105 and J192 stations far from the epicentre, and the post-earthquake deformation is still continuing.Combined with aftershock slip and viscoelastic dislocation theory, the post-earthquake deformation is simulated, and the GPS horizontal deformation after the earthquake is explained by these two mechanisms.The results show that the aftershock slip plays a major role in the initial stage of post-earthquake deformation, but gradually attenuates with the increase of time.The contribution of viscosity relaxation to the post-earthquake surface deformation observed by GPS can be reasonably explained by the combination of these two mechanisms.The GPS deformation simulation is used to estimate the mantle viscosity coefficient of the seismic region in the order of 1. 5 脳 1019 Pa / s.
【作者单位】： 中国地震局地震预测研究所(地震预测重点实验室);
【基金】：国家自然科学基金(41274098) 中国地震局地震行业科研专项(201508010);中国地震局地震预测研究所基本科研业务费专项(2013IES0407)~~
【分类号】：P315.7
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本文编号：1765944