Sediment and Solute Transport in Glacial Meltwater Streams
Sediment and Solute Transport in Glacial Meltwater Streams
复制标题
冰川融水流中的沉积物和溶质输送
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
M. Tranter
中科院分区：
文献类型：
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作者：
M. Tranter
本综述记录了冰川径流的悬浮沉积物和主要离子浓度，以了解对冰川流域沉积物和溶质通量的控制。冰川流域（冰川覆盖率>30%）的沉积物产量通常比类似的非冰川流域大一个数量级。值得注意的是，冰川盆地的沉积物产量与盆地面积成正比，这很可能是由于冰层厚度和冰通量增加而增加的结果，从而增加了冰下侵蚀的速度。冰川侵蚀的速度通常超过流域物质输送的速度，因此冰川消退后沉积物产量在 103-105 年的时间内保持较高水平。冰川径流中的离子浓度通常低于温带河水的离子浓度，但按特定径流衡量时，冰川流域的溶质产量与温带流域的溶质产量相似。冰川在溶解碳酸盐、硫化物、流体包裹体和硅酸盐矿物表面方面特别有效。这是冰下环境中细粒、地球化学反应性沉积物的产生以及许多冰川流域的高水通量的结果。冰下化学风化作用是微生物介导的。因此，冰川床充当微生物生命的避难所，其范围涵盖从完全有氧到完全缺氧的条件。
关键词：
化学风化；
侵蚀;
冰川；
物理风化；
径流
This review documents the suspended sediment and major ion concentrations of glacial runoff, with a view to understanding the controls on sediment and solute fluxes from glaciated catchments. The sediment yield from glaciated catchments (those with >30% glacial cover) is often an order of magnitude greater than those of similar, nonglaciated catchments. Remarkably, sediment yield from glacier basins scales with basin area, most likely as a consequence of thicker ice thicknesses and ice fluxes, which increase the rate of subglacial erosion. The rate of glacial erosion usually exceeds the rate of transport of material from the catchment, so that following deglaciation sediment yield remains high for periods of 103–105 years. The concentration of ions in glacial runoff is typically less than that of temperate river waters, yet the solute yield from glaciated catchments is similar to that of temperate catchments when scaled by specific runoff. Glaciers are particularly efficient in dissolving carbonates, sulfides, fluid inclusions, and the surfaces of silicate minerals. This is a consequence of the production of fine-grained, geochemically reactive sediments in subglacial environments and the high water flux through many glaciated catchments. Subglacial chemical weathering is microbially mediated. Hence, glacier beds act as refugia for microbial life, which spans the range from fully oxic to fully anoxic conditions.
Keywords:
chemical weathering;
erosion;
glaciers;
physical weathering;
runoff