Geodynamic modeling of thermal structure of subduction zones  

作　　者：LENG Wei MAO Wei 

机构地区：[1]Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences,University of Science and Technology of China [2]National Geophysical Observatory at Mengcheng

出　　处：《Science China Earth Sciences》2015年第7期1070-1083,共14页中国科学（地球科学英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2015CB856106)

摘　　要：During subduction processes, slabs continuously have heat exchange with the ambient mantle, including both conduction and advection effects. The evolution of slab thermal structure is one of the dominant factors in controlling physical and chemical property changes in subduction zones. It also affects our understanding of many key geological processes, such as mineral dehydration, rock partial melting, arc volcanism, and seismic activities in subduction zones. There are mainly two ways for studying thermal structure of subduction zones with geodynamic models: analytical model and numerical model. Analytical model provides insights into the most dominant controlling physical parameters on the thermal structure, such as slab age, velocity and dip angle, shear stress and thermal conductivity, etc. Numerical model can further deal with more complicated environments, such as viscosity change in the mantle wedge, coupling process between slabs and the ambient mantle, and incorporation of petrology and mineralogy. When applying geodynamic modeling results to specific subduction zones on the Earth, there are many factors which may complicate the process, therefore it is difficult to precisely constrain the thermal structure of subduction zones. With the development of new quantitative methods in geophysics and geochemistry, we may obtain more observational constraints for thermal structure of subduction zones, thus providing more reasonable explanations for geological processes related to subduction zones.During subduction processes, slabs continuously have heat exchange with the ambient mantle, including both conduction and advection effects. The evolution of slab thermal structure is one of the dominant factors in controlling physical and chemical property changes in subduction zones. It also affects our understanding of many key geological processes, such as mineral de- hydration, rock partial melting, arc volcanism, and seismic activities in subduction zones. There are mainly two ways for stud- ying thermal structure of subduction zones with geodynamic models： analytical model and numerical model. Analytical model provides insights into the most dominant controlling physical parameters on the thermal structure, such as slab age, velocity and dip angle, shear stress and thermal conductivity, etc. Numerical model can further deal with more complicated environ- ments, such as viscosity change in the mantle wedge, coupling process between slabs and the ambient mantle, and incorpora- tion of petrology and mineralogy. When applying geodynamic modeling results to specific subduction zones on the Earth, there are many factors which may complicate the process, therefore it is difficult to precisely constrain the thermal structure of subduction zones. With the development of new quantitative methods in geophysics and geochemistry, we may obtain more observational constraints for thermal structure of subduction zones, thus providing more reasonable explanations for geological processes related to subduction zones.

关 键 词：subduction zones thermal structure analytical model numerical model 

分 类 号：P542[天文地球—构造地质学]