Abstract:
The thermal conductivity and expansion coefficients are two significant parameters that have influence on the dynamic process of slab subduction. Due to the heterogeneity of Earth medium, these two coefficients are usually variable with depth. Unfortunately, such variations are often ignored in current modeling studies of geodynamics. The present study refers to the temperature-dependent thermal conductivity and expansion to simulate the dynamic process of slab subduction. The impact of thermal parameters and viscosity on slab geometry and the corresponding characteristics of mantle convection are analyzed. The modeling results show that the temperature-dependent thermal conductivity and expansion affect the subduction angle by changing the thermal and viscosity structure. The viscosity plays a critical role in controlling the slab dynamic evolution. The mantle convection is affected by viscosity structure and exhibits different patterns, such as layered convection and local multiple convection loops, etc.