Mega-earthquakes rupture flat megathrusts
Mega-earthquakes rupture flat megathrusts
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DOI：
10.1126/science.aag0482
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发表时间：
2016-11-25
期刊：
影响因子：
56.9
通讯作者：
De Barros, Louis
中科院分区：
文献类型：
--
作者：
Bletery, Quentin;Thomas, Amanda M.;De Barros, Louis
2004年的苏门答腊-安达曼地震和2011年的东北冲地震突出了我们对大地震破裂过程及其全球分布控制因素的认识上的差距：大地震的发生并不需要快速的会聚速度和年轻的浮力岩石圈。我们计算了世界主要俯冲带的曲率，表明大地震优先破裂平坦(低曲率)界面。简化的分析模型表明，抗剪强度的非均质性随曲率的增加而增加。与高度弯曲的断层相比，平坦的巨型断裂带的剪切强度更均匀，因此更有可能在大范围内同时超过。
The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution: A fast convergence rate and young buoyant lithosphere are not required to produce mega-earthquakes. We calculated the curvature along the major subduction zones of the world, showing that mega-earthquakes preferentially rupture flat (low-curvature) interfaces. A simplified analytic model demonstrates that heterogeneity in shear strength increases with curvature. Shear strength on flat megathrusts is more homogeneous, and hence more likely to be exceeded simultaneously over large areas, than on highly curved faults.