Subglacial stream

Subglacial streams are streams which flow in a channel at the bottom of an ice-sheet or a glacier, and are usually close to the glacier terminus or snout. These are fed by streams on top of the glacier which descend through ducts in the ice called moulins. The pressures are very high in these streams due to the huge mass of ice above them, consequently, they have very high erosive power meaning they will increase the volume of water flowing through, maintaining the high pressure. Some subglacial streams have the strange property of 'flowing' uphill due to the colossal pressures that are present.