Diapirism and topography
Diapirism and topography
复制标题
底辟作用和地形
DOI：
10.1111/j.1365-246x.1992.tb00117.x
复制
发表时间：
1992
影响因子：
2.8
通讯作者：
Y. Podladchikov
中科院分区：
文献类型：
--
作者：
A. Poliakov;Y. Podladchikov
摘要 使用标记和可变形拉格朗日网格的新数值技术用于研究上升底辟上方表面的变形。该方法允许以自洽的方式对自由表面边界进行建模。该方法使得研究非规则几何形状的许多不同问题成为可能。通过与初始阶段的解析解和成熟阶段的其他数值代码的比较来验证代码。我们的模拟得出以下结论。 (1) 底辟生长速率受粘度对比的影响比波长的影响更大。这是由于初期增长率差异较大所致。 (2) 底辟上方的最大高度随着波长的增加而线性增加，并且对于不同的粘度对比而言大致相同。 (3) 在给定深度处，低粘度底辟的标高将比等粘底辟高得多。对不同厚度的浮力层的比较表明，当两层厚度相等时产生最高的形貌。我们展示了地形行为对参数 R（两层之间的密度差与上层密度的比率）的依赖性。研究发现，在 R = 0.15 之前，形貌呈线性。它表明使用自由滑移边界条件的传统计算的地形后验估计在此限制内效果良好。
SUMMARY A new numerical technique using markers and a deformable Lagrangian mesh is used to study the deformation of the surface above a rising diapir. This method allows modelling of a free-surface boundary in a self-consistent way. The method makes it possible to investigate many different problems with non-regular geometry. The codes were verified through comparison with analytical solutions for the initial stages and with other numerical codes for mature stages. Our simulations led to the following conclusions. (1) The growth rate of the diapir is more strongly influenced by the viscosity contrast than the wavelengths. This is due to the strong growth rate difference during the initial stage. (2) The maximum elevation above the diapir linearly increases with increasing wavelength and is approximately the same for different viscosity contrasts. (3) The elevation will be considerably higher for a low-viscosity diapir at a given depth than for an isoviscous diapir. Comparisons for different thicknesses of the buoyant layer showed that the highest topography is produced when the two layers have equal thickness. We showed the dependence of the topographic behaviour on the parameter R (the ratio of the density difference between two layers to the density of the upper layer). It was found that topography behaves linearly up to R = 0.15. It indicates that a posteriori estimation of topography for traditional calculations using the free-slip boundary condition works well within this limit.