Geodynamic effects of subducted seamount at the Manila Trench: Insights from numerical modeling
Geodynamic effects of subducted seamount at the Manila Trench: Insights from numerical modeling
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马尼拉海沟俯冲海山的地球动力学效应：数值模拟的见解
DOI：
10.1016/j.tecto.2019.05.011
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发表时间：
2019-08
期刊：
影响因子：
2.9
通讯作者：
Ding Hanghang
中科院分区：
文献类型：
--
作者：
Cheng Zihua;Ding Weiwei;Faccenda Manuele;Li Jiabiao;Lin Xiubin;Ma Letian;Fang Penggao;Ding Hanghang
我们使用数值模拟来研究马尼拉海沟俯冲海山的地球动力学效应。通过改变活化体积（Vact）和凝聚力（C）等参数对岩石圈流变学、板块汇聚速度和俯冲板片年龄的影响，进行了一系列数值模拟实验。模拟结果表明，在适当的范围内改变Vact和C对俯冲的地球动力学过程的影响是有限的。较低的真空使板更容易下沉，并导致更陡的倾角。在100-300公里深处的俯冲作用下，更有可能发生板片断裂，而海山的存在则进一步促进断裂过程。收敛速度是影响中断时间和深度的关键参数。相反，在俯冲下，俯冲洋板块移动更快的板块上部，模型结果显示出非中断，稳定的俯冲。板坯年龄是另一个控制折断的因素，其中折断时间随板坯年龄而延长。没有海山的俯冲将导致断裂时间延迟约200万年。我们认为马尼拉海沟17 oN处的低速带是镇北-黄岩海山链俯冲作用的断裂事件的结果。再往北，例如北纬19度的位置，由于没有海山和更古老的海洋地壳，这将有利于俯冲过程中断裂时间的延迟。
We used numerical modeling to investigate the geodynamic effects of subducted seamounts at the Manila Trench. A series of numerical modeling experiments were conducted with variable parameters, including the activation volume (Vact) and cohesion (C), which influence lithospheric rheology, the plate convergence velocity, and the age of subducting slab. Modeling results indicate that varying theVactandCwithin an appropriate range have limited effects on the geodynamic process of subduction. A lowerVactallows the slab to sink more easily and results in a steeper dip angle. A slab break-off is more likely to occur under subduction at depths of 100–300 km, while the existence of a seamount further promotes the break-off process. The convergence rate is a key parameter affecting the break-off timing and depth. In contrast, under subduction where subducted oceanic plate move faster upper plate, the model results exhibit non-break-off, steady subduction. Slab age is another factor controlling break-off, where break-off time extends with slab age. A subduction without seamount will cause a ~2 Myr delay in break-off timing. We suggest that the low-velocity zone under the Manila Trench at 17oN is the result of a break-off event due to subduction of the Zhenbei-Huangyan Seamount Chain. Further to the north, such as the location at 19oN, the absence of seamount and an older oceanic crust would favor a delay in break-off timing during subduction.
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影响因子：
2.9
作者：
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影响因子：
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作者：
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通讯作者：
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DOI：
10.14379/iodp.pr.368x.2019
发表时间：
2018-08
期刊：
International Ocean Discovery Program Preliminary Report
影响因子：
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作者：
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通讯作者：
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