Dynamic Rupture Simulation Reproduces Spontaneous Multifault Rupture and Arrest During the 2016 Mw 7.9 Kaikoura Earthquake
Dynamic Rupture Simulation Reproduces Spontaneous Multifault Rupture and Arrest During the 2016 Mw 7.9 Kaikoura Earthquake
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DOI：
10.1029/2018gl080550
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发表时间：
2018-12
影响因子：
5.2
通讯作者：
R. Ando;Y. Kaneko
中科院分区：
文献类型：
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作者：
R. Ando;Y. Kaneko
2016年新西兰凯库拉地震是迄今为止观测到的最复杂的多断层破裂事件之一。我们进行动态破裂模拟，以评估考虑实际断层几何形状的相对简单的正演模型在多大程度上可以解释同震观测的特征。在没有精细参数调整的情况下，我们的模型再现了许多观测到的特征，包括多断层破裂、总体滑动分布、最大滑动和破裂停止的位置。特别是，我们的模型显示，由于区域构造应力场预期的较小的预应力水平，断裂系统两端的动态破裂会自发停止。模拟的源时间函数和观测推断的源时间函数都表现出相似的双峰，第二峰较大。结果阐明了三维断层几何在理解复杂多断层破裂动力学中的重要性。
The 2016 Kaikoura (New Zealand) earthquake is characterized as one of the most complex multifault rupture events ever observed. We perform dynamic rupture simulations to evaluate to what extent relatively simple forward models accounting for realistic fault geometry can explain the characteristics of coseismic observations. Without fine parameter tuning, our model reproduces many observed features including the multifault rupture, overall slip distribution, and the locations of the maximum slip and rupture arrest. In particular, our model shows spontaneous arrest of dynamic rupture at the both ends of the ruptured fault system due to smaller prestress levels expected from a regional tectonic stress field. Both the simulated and the observationally inferred source time functions show similar double peaks with a larger second peak. The results illuminate the importance of the 3‐D fault geometry in understanding the dynamics of complex multifault rupture.