Meltwater - Glacial Meltwater

Glacial Meltwater

Glacial meltwater comes from glaciers that have receded over time. Often, there will be rivers flowing through glaciers into lakes. These brilliantly blue lakes get their color from "rock flour", sediment that has been transported through the rivers to the lakes. This sediment comes from rocks grinding together underneath the glacier. The fine powder is then suspended in the water and refracts sunlight, giving the milky turquoise appearance.

Meltwater also acts as a lubricant in the basal sliding of glaciers. Using GPS measurements to study ice flow has revealed that glacial movement is greatest in summer when the meltwater levels are highest.