Revealing the deep structure and rupture plane of the 2010 Maule, Chile earthquake (Mw = 8.8) using wide angle seismic data
Revealing the deep structure and rupture plane of the 2010 Maule, Chile earthquake (Mw = 8.8) using wide angle seismic data
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利用广角地震数据揭示 2010 年智利马乌莱地震（Mw = 8.8）的深层结构和破裂面
DOI：
10.1016/j.epsl.2011.04.025
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发表时间：
2011
影响因子：
5.3
通讯作者：
M. Thorwart
中科院分区：
文献类型：
--
作者：
Eduardo Moscoso;I. Grevemeyer;E. Contreras‐Reyes;E. Flueh;Y. Dzierma;W. Rabbel;M. Thorwart
2010年2月27日的Maule地震（Mw = 8.8）使纳斯卡-南美洲板块边界断裂约400公里，造成数百人死亡和数十亿美元的物质损失。本文利用地震折射和广角资料对断裂带的弧前构造和俯冲带进行了约束。结果表明，这是一个宽约40 km的楔形体，其典型的沉积速度被解释为前缘吸积棱镜（FAP）。在FAP成像的陆地上，速度模型显示出一个突然的速度对比，表明岩石变化被解释为FAP与古增生棱镜（backstop）之间的接触。支撑位置与余震向海边界重合，确定了同震断裂和发震带的上倾边界。此外，余震的向海边界与整个地震断裂带（33°S - 38.5°S）的陆架断裂位置一致，这被解释为沿边缘的背挡位置。已公布的断裂带南北边界地震剖面也显示，在距形变前缘约30 km处存在强烈的水平速度梯度地震支撑。俯冲洋壳顶部的地震广角反射限制了近海板块边界的位置，倾斜约10°。将Maule地震的震中投影到我们导出的板块间边界上，产生了一个大约20公里深的震源，这意味着这次地震在发震带中间的某个地方成核，既不是在其上倾也不是在其下倾极限。
The 27 February, 2010 Maule earthquake (Mw = 8.8) ruptured ~ 400 km of the Nazca-South America plate boundary and caused hundreds of fatalities and billions of dollars in material losses. Here we present constraints on the fore-arc structure and subduction zone of the rupture area derived from seismic refraction and wide-angle data. The results show a wedge shaped body ~ 40 km wide with typical sedimentary velocities interpreted as a frontal accretionary prism (FAP). Landward of the imaged FAP, the velocity model shows an abrupt velocity-contrast, suggesting a lithological change which is interpreted as the contact between the FAP and the paleo accretionary prism (backstop). The backstop location is coincident with the seaward limit of the aftershocks, defining the updip limit of the co-seismic rupture and seismogenic zone. Furthermore, the seaward limit of the aftershocks coincides with the location of the shelf break in the entire earthquake rupture area (33°S–38.5°S), which is interpreted as the location of the backstop along the margin. Published seismic profiles at the northern and southern limit of the rupture area also show the presence of a strong horizontal velocity gradient seismic backstop at a distance of ~ 30 km from the deformation front. The seismic wide-angle reflections from the top of the subducting oceanic crust constrain the location of the plate boundary offshore, dipping at ~ 10°. The projection of the epicenter of the Maule earthquake onto our derived interplate boundary yielded a hypocenter around 20 km depth, this implies that this earthquake nucleated somewhere in the middle of the seismogenic zone, neither at its updip nor at its downdip limit.
影响因子：
2.8
作者：
S. Peyrat;R. Madariaga;E. Buforn;J. Campos;G. Asch;J. Vilotte
通讯作者：
S. Peyrat;R. Madariaga;E. Buforn;J. Campos;G. Asch;J. Vilotte
影响因子：
3.9
作者：
Ivandic, Monika;Grevemeyer, Ingo;McIntosh, Kirk
通讯作者：
McIntosh, Kirk