New Mantle Convection Models Constrained by Seismic Tomography Data

It is supposed that the heterogeneity of the mantle indicated by seismic tomography data is caused by thermal convection. In this case the speed heterogeneity of seismic waves can be transformed to density (or temperature) anomalies. By taking account of the three thermodynamic equations of fluid and considering the effects of nonliner terms in these equations, the density anomalies are regarded as inner loads to drive the mantle convection in our model. The mantle convection patterns with different Rayleigh numbers up to 106 are computed by using the seismic tomography model SH12WM13. The results show that the mantle flow patterns depend on not only the seismic tomography data set, but also the dynamic frame of the mantle and its response function restricted by thermodynamic parameters and boundary conditions. There are complex flow patterns in computed models when the Rayleigh number is going to be higher. It is suggested that regional layer shape convection and multilayer -like convection may exist in the Earth's mantle.

[1]  A. Yamaji.  Periodic hotspot distribution and small-scale convection in the upper mantle , 1992 .

[2]  G. Schubert,et al.  Thermal convection of an internally heated infinite Prandtl number fluid in a spherical shell. [earth core-mantle-surface model , 1980 .

[3]  L. Kroenke,et al.  Intermediate-wavelength (400-600 km), South Pacific geoidal undulations: their relationship to linear volcanic chains , 1991 .

[4]  A. Dziewoński,et al.  Joint inversions of seismic and geodynamic data for models of three—dimensional mantle heterogeneity , 1994 .

[5]  A. Cazenave,et al.  Locally layered convection inferred from dynamic models of the Earth's mantle , 1995, Nature.

[6]  R. Fu,et al.  Thermodynamical response of the mantle to a moving upper boundary , 1992 .

[7]  D. L. Anderson,et al.  Preliminary reference earth model , 1981 .

[8]  McSween Hy,et al.  Evidence for Life in a Martian Meteorite , 1997 .

[9]  B. Hager,et al.  Mantle convection and the state of the earth's interior , 1987 .

[10]  J. Weissel,et al.  Evidence for Small-Scale Mantle Convection From Seasat Altimeter Data , 1986 .

[11]  Fu Rong-Shan.  A numerical study of the effects of boundary conditions on mantle convection models constrained to fit the low degree geoid coefficients , 1986 .

[12]  Fabien Dubuffet,et al.  Multiple scales in mantle convection , 2000 .

[13]  D. Loper.  A simple model of whole-mantle convection , 1985 .

[14]  Robert W. Clayton,et al.  Lower mantle heterogeneity, dynamic topography and the geoid , 1985, Nature.

[15]  M. McNutt.  Earth science: The mantle's lava lamp , 1999, Nature.

[16]  Wei-jia Su,et al.  Degree 12 model of shear velocity heterogeneity in the mantle , 1994 .

[17]  D. Vasco,et al.  Whole Earth structure estimated from seismic arrival times , 1998 .

[18]  R. Hilst,et al.  Compositional stratification in the deep mantle , 1999, Science.

[19]  Mantle convection and visoelasticity , 1985 .

[20]  R. Peltier,et al.  Viscous flow models of global geophysical observables: 1. Forward problems , 1991 .

[21]  D. Yuen,et al.  Effect of the mid-mantle viscosity and phase-transition structure on 3D mantle convection , 2000 .

[22]  E. R. Engdahl,et al.  Evidence for deep mantle circulation from global tomography , 1997, Nature.

[23]  Thomas H. Jordan,et al.  Aspherical Earth structure from fundamental spheroidal-mode data , 1982, Nature.