Wave transport of deep mantle material
Wave transport of deep mantle material
复制标题
深部地幔物质的波传输
作者：
J. Whitehead;K. Helfrich
具有一定密度和粘度的流体可以通过浮力Poiffille流上升，该浮力Poiffille流通过在具有更大密度和粘度的第二流体内的微流器1。这种管道表现出丰富的非线性系统的行为特征，其中一个方面是孤波的形成2，3。在这里，我们提出了这些系统的理论和实验研究。这两种方法都表明，孤立波陷阱中的封闭流线的细胞的材料和中心的流线速度比波速快。因此，深层物质的包裹被直接向上输送很长的距离。这与通常的情况相反，在通常的情况下，波通过介质的传播仅引起流体粒子的小位移。与普通管流中的材料相比，这些包裹中的材料将远不受来自周围环境的扩散的污染。此外，孤立波在向上输送物质方面比浮力球更有效。我们认为，这种波可能存在于地球的地幔，输送未污染的深地幔物质的地球表面。
Fluid with a certain density and viscosity can rise by buoyant Poiseuille flow through a conduit1 within a second fluid of greater density and viscosity. Such conduits exhibit a rich behaviour characteristic of nonlinear systems, an aspect of which is the formation of solitary waves2,3. Here we present theoretical and experimental studies of these systems. Both approaches reveal that solitary waves trap material in a cell with closed streamlines and that the central streamline velocity is faster than the wave speed. Hence, parcels of deep material are transported directly upward over large distances. This is in contrast to the usual situation in which wave propagation through a medium causes only small displacement of fluid particles. Material in these parcels will be far less contaminated by diffusion from the surroundings than would be material in ordinary pipe flow. In addition, solitary waves are more efficient than buoyant spheres at conveying material upward. We suggest that such waves might exist in the Earth's mantle, conveying uncontaminated deep mantle material to the surface of the Earth.