Geoid and topographic swells over temperature‐dependent thermal plumes in spherical‐axisymmetric geometry
Geoid and topographic swells over temperature‐dependent thermal plumes in spherical‐axisymmetric geometry
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球轴对称几何中温度相关热羽流的大地水准面和地形膨胀
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
S. King
中科院分区：
文献类型：
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作者：
S. King
在中等瑞利数的球-轴对称几何形状中，在恒定粘性热羽流上的大地水准面和地形剖面与以前在其他几何形状中的研究结果进行了比较。球轴对称模型中的羽流比笛卡尔或圆柱轴对称几何中的羽流产生更大的大地水准面异常;然而，羽流上的地形异常小于圆柱轴对称几何中的相应异常，但大于笛卡尔几何中的异常。对于温度依赖性粘度流体中的羽流，与具有相同背景粘度分布的恒定粘度流体相比，大地水准面和地形分布减少了两倍。在这种情况下，地幔柱周围的径向平均温度分布在岩石圈下方形成了一个低粘度的“层”。
Geoid and topographic profiles over constant‐viscosity thermal plumes in spherical‐axisymmetric geometry at moderate Rayleigh numbers are compared with results from previous studies in other geometries. Plumes in spherical‐axisymmetric models produce larger geoid anomalies than plumes in either Cartesian or cylindrical‐axisymmetric geometries; however, the topographic anomalies over the plumes are smaller than the corresponding anomalies in a cylindrical‐axisymmetric geometry but larger than those in a Cartesian geometry. For plumes in a temperature‐dependent viscosity fluid, the geoid and topographic profiles are reduced by a factor of two when compared to a constant viscosity fluid with the same background viscosity profile. In this case, the radially‐averaged temperature profile around the plume creates a low‐viscosity ‘layer’ beneath the lithosphere.