Calibration of a new model for mantle viscosity: the role of grain boundaries from bicrystal experiments

GSTDTAP

项目编号	NE/S001727/1
	Calibration of a new model for mantle viscosity: the role of grain boundaries from bicrystal experiments
	Julian Mecklenburgh
主持机构	University of Manchester
项目开始年	2018
	2018-08-01
项目结束日期	2021-07-31
资助机构	UK-NERC
项目类别	Research Grant
项目经费	165959(GBP)
国家	英国
语种	英语
英文摘要	The solid rocks within Earth's interior can flow, analogous to ice in a glacier, given sufficient time and temperature. This flow, or viscous deformation, has a strong influence on a variety of processes over short and long time scales. Over long time scales, the viscous deformation of rocks controls the motion of Earth's tectonic plates. Over short timescales, the viscous deformation of rocks controls the rate at which stresses buildup on overlying, earthquake-generating faults. However, there are major gaps in our understanding of how these rocks deform, which results in significant uncertainties in modeling these large-scale processes on Earth. One of the largest sources of uncertainty is in understanding how grain boundaries, that is the regions between crystals, deform at extreme conditions. This lack of understanding has major implications for predicting processes in Earth. For instance, if grain boundaries are weak relative to the interiors of crystals, then the rates at which stresses build up on large, earthquake-generating faults may increase tenfold. To address this shortcoming, we will carry out experiments at extreme conditions in which we slide two crystals past each other. In some cases, we will add water to the boundary to test if water increases how fast the crystals slide. The data from many experiments will be used to create an equation that describes how fast the crystals slide under a wide range of conditions. To investigate how individual grain boundaries influence the properties of a rock made up of many crystals, these equations will be incorporated into numerical simulations that predict the behavior of an aggregate of crystals. These simulations will be used to understand the importance of grain boundaries in a variety of important large-scale geologic processes.
来源学科分类	Natural Environment Research
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/87278
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Julian Mecklenburgh.Calibration of a new model for mantle viscosity: the role of grain boundaries from bicrystal experiments.2018.