文章基本信息

标题：Numerical models of convection in a rheologically stratified oceanic upper mantle: Early results
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作者：Mamoru Kato
期刊名称：Earth, Planets and Space
电子版ISSN：1880-5981
出版年度：2014
卷号：50
期号：11
页码：1047-1054
DOI：10.1186/BF03352199
出版社：Springer Verlag
摘要：Recent seismological evidences imply that the boundary between the lithosphere and asthenosphere is a compositional boundary in the oceanic upper mantle, and a rapid increase of viscosity at this boundary is suggested. We modeled a thermal convection in the oceanic mantle numerically using the finite element method, and investigated geodynamical consequences of such a rheological layering. Early results from both quasi-steady state flows and time-dependent flows are presented in this report. We assumed a temperature- and depth-dependent viscosity law so that both the thermal effects and those of layering are taken into account. The effect of a high-viscosity layer (HVL) is small on the flow and the temperature field. Velocity gradients in the HVL are small in both directions, and the velocity field is well approximated by a one-dimensional channel flow. The HVL acts as a low-pass filter of the dynamic topography.