Kinematics and Dynamics of Continental Deformation and the Effective Viscosity of Continental Lithosphere

大陆变形的运动学和动力学以及大陆岩石圈的有效粘度

• 批准号: 9527024
• 负责人: Peter Molnar
• 金额: $ 15.37万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527024&HistoricalAwards=false
• 关键词: Kinematics; Dynamics; Continental; Deformation; Effective

9527024 Molnar The key link between dynamic processes and the resulting large-scale kinematics of continental deformation is the constitutive law relating stress to strain rate. The PI proposes to determine lateral variations in such constitutive relationships across deforming continental regions where continuous deformation approximates the kinematics of continental tectonics. Calculated velocity fields will yield an internally consistent strain-rate field that the PI will use to determine the laterally varying, vertically averaged, effective viscosity of deforming continental lithosphere. This study will test the validity and limitation of the thin viscous sheet as a model for large-scale continental dynamics. Quantifying effective viscosity will reveal whether regions of low strain rate deform slowly because of high strength or because of low stress. A decrease in effective viscosity with increasing strain-rate will allow inferences of the relative importance of friction on faults and ductile deformation at depth in resisting deformation. In addition, the study of kinematics alone will address specific conundra of Asian tectonics.

小行星9527024 动力学过程和由此产生的大陆变形的大规模运动学之间的关键联系是将应力与应变率联系起来的本构律。 PI建议，以确定横向变化，在这种本构关系的变形大陆地区，连续变形近似大陆构造的运动学。 计算的速度场将产生内部一致的应变率场，PI将使用该应变率场来确定变形大陆岩石圈的横向变化、垂直平均、有效粘度。 这项研究将检验薄粘性片作为大尺度大陆动力学模型的有效性和局限性。 量化有效粘度将揭示低应变率区域是否由于高强度或低应力而缓慢变形。 有效粘度随应变速率的增加而减小，这将使我们能够推断断层摩擦和深部韧性变形在抵抗变形中的相对重要性。 此外，运动学研究本身将解决亚洲构造的具体难题。