The processes of erosion - Meltwater erosion Flashcards
What is the impact of meltwater beneath the glacier in terms of erosion?
Meltwater beneath the glacier causes both physical and chemical erosion.
Where does meltwater erosion increase in importance?
Meltwater erosion increases in importance towards the snout of the glacier where there is more meltwater.
Meltwater flowing at the base of a glacier erodes rock by which processes?
Meltwater flowing at the base of a glacier erodes rock by the same processes as surface streams, through the combined action of abrasion, hydraulic action, attrition and solution, except that the meltwater flows across the bedrock under hydrostatic pressure due to the weight of the overlying ice.
What is the impact of meltwater flowing across the bedrock under hydrostatic pressure due to the weight of the overlying ice?
It causes meltwater streams to flow faster, with the result that the erosive potential of meltwater is much greater than surface rivers, influencing landforms beyond the limit of the ice margin itself.
What is hydrostatic pressure?
Hydrostatic pressure - The pressure that any fluid in a confined space exerts on the bedrock surrounding it.
What is hydraulic action?
Hydraulic action - The erosion that occurs when the motion of water against a rock surface produces mechanical weathering. Most generally, it is the ability of moving water (flowing or waves) to dislodge and transport rock particles.
What is attrition?
Attrition is the process whereby the particles transported by glaciers, rivers, wind and waves are reduced in size as a result of continual impacts with one another.
Where does solution occur?
Solution, which is a form of chemical weathering, occurs where glacial meltwater dissolves minerals and carries them away, especially in areas of limestone or chalk because of their susceptibility to carbonation weathering.
