Global plate tectonics and mantle convection with damage memory

GSTDTAP

项目编号	1853856
	Global plate tectonics and mantle convection with damage memory
	Thorsten Becker (Principal Investigator)
主持机构	University of Texas at Austin
项目开始年	2019
	2019-03-15
项目结束日期	2022-02-28
资助机构	US-NSF
项目类别	Continuing grant
项目经费	115000(USD)
国家	美国
语种	英语
英文摘要	Plate tectonics is fundamental for Earth's evolution and the surface expression of mantle convection. However, it is unclear how the narrow and strongly deforming boundaries between the more rigid plates form. The reactivation of plate boundaries, in particular, gives the continental plates a long-term hysteresis with profound implications for tectonics. This project seeks to better understand the causes and consequences of damage memory in convection. Funding will support a female graduate student and speak to issues outside geodynamics including the quest for a general law describing fault behavior from the seismic cycle to long-term Earth evolution. The project will also support new international collaborations, and research outcomes will be disseminated widely, including for UT Austin's GeoFORCE K-12 outreach program. This project will implement strain-dependent weakening into global, numerical convection models in order to explore the style of "plate tectonics" that is generated by visco-plastic mantle flow. Incorporating such rheological memory will allow study of the full range of tectonic behavior, including how plate boundary evolution and plate motions are linked with the deep mantle. A range of viscous damage formulations will be explored and benchmarked against grain-size evolution theories and other suggested mechanisms for strain-localization, such as formation of shear bands and mechanical anisotropy due to lattice preferred orientation of olivine. Model results will be compared with geological constraints including plate kinematics, with particular focus on the time-dependence of plate boundary geometry, plate speeds and sizes, and seafloor age distributions. The overall goal is to develop a theoretical understanding of the role of tectonic inheritance in terrestrial planet evolution and heat transport. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/213345
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Thorsten Becker .Global plate tectonics and mantle convection with damage memory.2019.