Crustal deformation dynamics and stress evolution during seamount subduction: High‐resolution 3‐D numerical modeling
Crustal deformation dynamics and stress evolution during seamount subduction: High‐resolution 3‐D numerical modeling
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海山俯冲过程中的地壳变形动力学和应力演化：高分辨率 3D 数值模拟
DOI：
10.1002/2016jb013250
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Gerya
中科院分区：
文献类型：
--
作者：
J. Ruh;V. Sallarés;C. Ranero;T. Gerya
海山或海底火山经常沿着沿着目前活跃的俯冲带与上覆地壳碰撞，局部改变应力和永久变形模式。这一过程的动力学尚未完全了解，并提出了海山-地壳相互作用的几种端元假设。在这里，我们使用高分辨率的3-D数值模型来研究地壳变形的演化和应力分布在上板俯冲海山的俯冲引起的。研究了上板块强度、俯冲界面强度和地壳应变弱化的动力学效应。实验结果表明，不同的海山-地壳相互作用情景形成了特征性的地壳破裂模式。锯齿状海山使上覆板块沿沿着一条与下冲海山一样宽的走廊发生强烈变形，其方式是不断移动以海山延伸部分为基础的近垂直剪切带。在最初的海山碰撞过程中形成了一个折返体。海山顶部的地形隆起和侧脊因进一步的海山俯冲而出现。获得的应力模式显示，在海山的后部上方有大的超压区，在海山的向沟侧翼上方有大的负压区。数值实验的结果与地震反射图像和地震速度模型相一致的上部板块的海山俯冲沿着中美洲海沟地区，并提供了重要的见解，长期存在的问题，是否俯冲海山和粗糙的海底作为障碍或凹凸不平的巨型逆冲地震。
Seamounts or submarine volcanoes frequently collide with the overriding crust along presently active subduction zones locally modifying stress and permanent deformation patterns. Dynamics of this process is not fully understood, and several end‐member scenarios of seamount‐crust interaction are proposed. Here we use high‐resolution 3‐D numerical models to investigate evolution of crustal deformation and stress distribution within the upper plate induced by the underthrusting of subducting seamounts. The dynamical effects of the upper plate strength, subduction interface strength, and strain weakening of the crust are investigated. Experiment results demonstrate that characteristic crustal fracturing patterns formed in response to different seamount‐crust interaction scenarios. Indenting seamounts strongly deform the overriding plate along a corridor as wide as the underthrusting seamount by constantly shifting subvertical shear zones rooted at the seamount extensions. A reentrant develops during initial seamount collision. A topographic bulge atop the seamount and lateral ridges emerge from further seamount subduction. Obtained stress pattern shows areas of large overpressure above the rearward and large underpressure above the trenchward flank of the seamount. Results of numerical experiments are consistent with seismic reflection images and seismic velocity models of the upper plate in areas of seamount subduction along the Middle America Trench and give important insights into the long‐lasting question, whether subducting seamounts and rough seafloor act as barriers or asperities for megathrust earthquakes.
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影响因子：
18.3
作者：
Satish C. Singh;N. Hananto;Maruf Mukti;David P. Robinson;Shamita Das;A. Chauhan;H. Carton;B. Gratacos;Stephan Midnet;Y. Djajadihardja;H. Harjono
通讯作者：
Satish C. Singh;N. Hananto;Maruf Mukti;David P. Robinson;Shamita Das;A. Chauhan;H. Carton;B. Gratacos;Stephan Midnet;Y. Djajadihardja;H. Harjono
影响因子：
18.3
作者：
M. Moreno;C. Haberland;O. Oncken;A. Rietbrock;S. Angiboust;O. Heidbach
通讯作者：
M. Moreno;C. Haberland;O. Oncken;A. Rietbrock;S. Angiboust;O. Heidbach
影响因子：
3.7
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C. Ranero;I. Grevemeyer;H. Sahling;U. Barckhausen;C. Hensen;K. Wallmann;W. Weinrebe;P. Vannucchi;R. Huene;K. Mcintosh
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C. Ranero;I. Grevemeyer;H. Sahling;U. Barckhausen;C. Hensen;K. Wallmann;W. Weinrebe;P. Vannucchi;R. Huene;K. Mcintosh
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影响因子：
4.2
作者：
Zeumann;A. Hampel
通讯作者：
A. Hampel
影响因子：
64.8
作者：
Schurr, Bernd;Asch, Guenter;Vilotte, Jean-Pierre
通讯作者：
Vilotte, Jean-Pierre