| 项目编号: | 1620618
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| 项目名称: | Integrating the LPO Constraint into 3D Subduction Dynamics Simulations |
| 作者: | Magali Billen
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| 承担单位: | University of California-Davis
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| 批准年: | 2016
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| 开始日期: | 2016-07-01
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| 结束日期: | 2019-06-30
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| 资助金额: | 189098
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | subduction
; lpo structure
; seismic anisotropy
; project
; subduction zone
; deformation
; observation
; first time lpo calculation
; subduction system parameter
; subduction system
; processing simulation
; time-dependent simulation
; tectonic plate
; lpo calculation
; mantle simulation code aspect
; mantle
; large-scale 3-d simulation
|
| 英文摘要: | Subduction is the process by which one tectonic plate sinks beneath another tectonic plate into the Earth's mantle. Subduction zones are some of the most tectonically and seismically active areas on the planet. They have large destructive earthquakes and abundant volcanic activity. This geologic activity is driven by the sinking tectonic plate, which causes deformation (build up of stresses) and melting in the surrounding mantle. These subsurface processes are observed indirectly using geophysical and geochemical methods. Of these observations, only seismic anisotropy can be directly linked to the spatial pattern of deformation caused by sinking of the subducted plate. To make the link from observations of seismic anisotropy to deformation in the mantle scientists need to calculate a fabric that develops in the deformed rocks called lattice-preferred orientation (LPO). The proposed research will simulate subduction to predict the LPO structure. This is the first time LPO calculations will be fully incorporated into large-scale 3-D simulations. By analyzing these results the investigators will provide better interpretations of seismic anisotropy observation in terms of the 3-D deformation in the shallow mantle. A better understanding of the mantle deformation (stresses) is important for addressing natural hazards due to earthquakes and volcanic activity in subduction zones. All of the computational modules developed for the project will be made publicly available to advance similar studies beyond this project. The project will train a PhD student in computational modeling, analysis of complex systems and how to communicate scientific results to a broad audience. The project will also provide research opportunities for undergraduates to develop their skills in critical-thinking, project development, leadership, and the scientific method.
The proposed research will create, run and analyze approximately 16, 3-D, time-dependent simulations of subduction using the mantle simulation code ASPECT, with fully-integrated calculations of the evolution of LPO structure throughout the model domain using tracer particles and a kinematic (D-Rex) LPO calculation. The models will be analyzed to identify features in the LPO structure that are related to different parameters (physical properties, geometry) defining the subduction system. They will also be analyzed to identify patterns in the LPO structure related to the phase of subduction and state of deformation in the slab. Predictions of seismic anisotropy observed at the surface will be made for a subset of models designed to match the general characteristics of the Cascadia, S. America and Middle America subduction zones. The investigators will then compare the predicted and observed seismic anisotropy to determine how the observations are related to flow in the mantle and deformation of the slab. The graduate student researcher, will be primarily responsible for creating, running, and processing simulations, as well as the analysis of the results in terms of subduction system parameters and phase/state of subduction. The PI will be primarily responsible for writing the post-processing codes that takes the LPO structure from ASPECT, calculates the elastic tensor and resulting seismic anisotropy, and for the comparison of these predictions to observations from three locations. They anticipate publication of at least six manuscripts with the major findings of the project. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/91967
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Magali Billen. Integrating the LPO Constraint into 3D Subduction Dynamics Simulations. 2016-01-01.
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