Subglacial streams are conduits of glacial meltwater that flow at the base of glaciers and ice caps.[1] Meltwater from the glacial surface travels downward throughout the glacier, forming an englacial drainage system consisting of a network of passages that eventually reach the bedrock below, where they form subglacial streams.[1] Subglacial streams form a system of tunnels and interlinked cavities and conduits, with water flowing under extreme pressures from the ice above; as a result, flow direction is determined by the pressure gradient from the ice and the topography of the bed rather than gravity.[1] Subglacial streams form a dynamic system that is responsive to changing conditions, and the system can change significantly in response to seasonal variation in meltwater and temperature.[2] Water from subglacial streams is routed towards the glacial terminus, where it exits the glacier.[2] Discharge from subglacial streams can have a significant impact on local, and in some cases global, environmental and geological conditions.[3] Sediments, nutrients, and organic matter contained in the meltwater can all influence downstream and marine conditions.[4] Climate change may have a significant impact on subglacial stream systems, increasing the volume of meltwater entering subglacial drainage systems and influencing their hydrology.[2]
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