geo glaciation Flashcards
what is melt water erosion
it is when sediment and water are trapped in a glacier eventually it bursts causing all the water and sediment to erode the landscape. eg glen of the down co wicklow
what is a cirque and arêtes
its when snow builds up in a natural hollow in the mountain. The snow is compressed which forms a glacier plucking and abrasion make the hollow larger this builds up over time making the glaciers to become larger this causes the glacier to rotate out of the hollow which then its pulled out by gravity the water left in it is called an Corrie lake or a tarn and when 2 cirques from back to back an arêtes is formed e.g. upper lough bray co wicklow it is a form of erosion
what is an erratic
it when glaciers move they pluck rocks from the ground the rocks are then transported a long distance with the glacier. As the glacier melts it deposits the rock on a new area are made up of different rock e.g. when limestone ends up on granite areas a well known erratic is the bubble rock in Maine USA
what is a lateral moraine
these are found at the side of a glacier, the sediments from the freeze thaw action above fall on the sides of glaciers
what is a medial moraine
it is when 2 glaciers meet and there lateral moraines meet and when the glacier melts this material is deposited by medial moraines
what is a ground moraine
these are found at the base of the glacier they are sediment being plucked from the valley floor by the glacier
what is a terminal moraine
these are at the front o the glacier it is were all the weathered material (e.g. scree) is lying across the valley
what is glacial deposition
as a glacier melts boulders rocks or sediments tapped on top or in the glacier fall directly on the landscape
