论文部分内容阅读
基于2011年3月~2015年9月的GPS观测数据,研究了2011年日本M_W9.0地震引起的震后位移时空变化,分析震后4.5a内震后断层余滑和粘滞性松弛对震后位移场的贡献。基于子断层叠加的思想,对Tanaka的粘弹性球体位错理论配套计算程序(环型解部分)加以改进,克服其近场计算精度不足(甚至错误)的缺陷,提高了近场震后位移的计算精度。利用弹性球体位错理论配套计算程序和改进后的粘弹性球体位错理论配套计算程序,分别计算2011年日本M_W9.0地震产生的同震位移,两组结果的差异仅占信号的1%左右,验证了对粘弹性球体位错理论配套计算程序改造的正确性。最后,结合震后3~4.5aGPS观测数据,利用Tanaka的粘弹性球体位错理论确定了2011年日本M_W9.0地震震中周边区域地幔粘滞性系数,其最佳拟合值为6×10~(18)Pa·s。
Based on the GPS observation data from March 2011 to September 2015, the spatial and temporal variations of post-earthquake displacement caused by the M_W 9.0 earthquake in Japan in 2011 were studied. After 4.5 Earthquake, Post-displacement field contribution. Based on the idea of sub-fault superposition, Tanaka’s viscoelastic spherical dislocation theory supporting program (ring-shaped solution) is improved to overcome the shortcomings of its near-field calculation accuracy is not enough (or even wrong) to improve the near-field post-earthquake post-earthquake displacement calculation accuracy. Using the matching program of elastic spherical dislocation theory and the improved computational program of viscoelastic spherical dislocation theory, the coseismic displacements generated by the 2011 M_W 9.0 earthquake in Japan are calculated separately, and the difference between the two sets of results accounts for only about 1% of the signal , Which verifies the correctness of the reconstruction of the calculation program for the viscoelastic ball dislocation theory. Finally, based on 3 ~ 4.5aGPS post-earthquake observation data, the viscoelastic spherical dislocation theory of Tanaka was used to determine the mantle viscous coefficient of the M_W 9.0 earthquake near the epicenter in 2011, and the best fitting value was 6 × 10 ~ (18) Pa · s.