Shallow Dynamic Overshoot and Energetic Deep Rupture in the 2011 Mw 9.0 Tohoku-Oki Earthquake
Shallow Dynamic Overshoot and Energetic Deep Rupture in the 2011 Mw 9.0 Tohoku-Oki Earthquake
复制标题
DOI：
10.1126/science.1207020
复制
发表时间：
2011-06-17
期刊：
影响因子：
56.9
通讯作者：
Beroza, Gregory C.
中科院分区：
文献类型：
--
作者：
Ide, Satoshi;Baltay, Annemarie;Beroza, Gregory C.
在矩震级（M-W）9.0的东北冲地震破裂特征的强烈空间变化控制了震动的强度和随之而来的海啸的大小。震源成像显示，破裂包括一个小的初始阶段，深破裂长达40秒，广泛的浅破裂在60至70秒，和持续的深破裂持续超过100秒。浅倾断层和顺性上盘的组合可能使海沟附近发生了大的浅滑动。在高滑动区域的正常断层余震表明断层上的动态超调。尽管总的滑动量很大，但破裂较浅的部分在高频下辐射很弱，而破裂较深的部分在高频下辐射很强。
Strong spatial variation of rupture characteristics in the moment magnitude (M-w) 9.0 Tohoku-Oki megathrust earthquake controlled both the strength of shaking and the size of the tsunami that followed. Finite-source imaging reveals that the rupture consisted of a small initial phase, deep rupture for up to 40 seconds, extensive shallow rupture at 60 to 70 seconds, and continuing deep rupture lasting more than 100 seconds. A combination of a shallow dipping fault and a compliant hanging wall may have enabled large shallow slip near the trench. Normal faulting aftershocks in the area of high slip suggest dynamic overshoot on the fault. Despite prodigious total slip, shallower parts of the rupture weakly radiated at high frequencies, whereas deeper parts of the rupture radiated strongly at high frequencies.