How are glaciers created?

Answer 1

Glaciers are made up fallen snow which over many years have compressed together to form large thickened ice masses. Glaciers form when snow stays in one area long enough to transform into ice. The amazing thing about glaciers is their ability to move. Due to the sheer mass, glaciers move like very slow rivers. Some glaciers can be as small as football field's whereas some are hundreds of kilometres in size. A valley that is carved by a glacier, or glacial valley, is normally u-shaped. The valley becomes visible when a glacier has formed on it due to the landscape shape. When the ice recedes or thaws, the valley is left with small boulders that were transported within the ice. The floor gradient does not affect the valleys shape, the size of the glacier does. Continuously flowing glaciers, especially in the ice age, also very large sized glaciers carve wide, deep incised valleys. Examples of U-shaped valleys are found in every mountain region that has experienced glaciation, usually during the Pleistocene ice ages. Most present U-shaped valleys started a V-shaped before glaciation. The glaciers have carved it out wider and deeper, resulting in the change of the shape. This carries on through the glacial erosion processes of glaciation and abrasion, which results in large rocks being carried in the glacier. This is also known as plucking. The rocks scrape against the side of the mountain and gorges and groves out big chunks of the mountain. Some examples of tarns are two in Easdale. Huge forces caused by millions of tonnes of ice have scooped out of the main Easdale tarn. Lower down the valley are several bowls which are filled with bog today. Moraine is collected by the glacier as it scrapes its way downhill and it is left behind when the glacier melts. The lumpy appearance of the land across the tarn is due to the piles of moraine left behind when the glacier melted. This kind of landscape is very common around corries. It is called hummocky moraine. Most tarns are dammed in by piles of moraine and in this case at Easdale. Where a stream leaves a tarn it cuts through the moraine at an outflow. At the back of tarns we usually see a shattered wall of rock, a headwall. These have been made by the plucking action of the ice as it forces its way down the rock face. A material called boulder clay is left on the floor of the valley. As the ice melts and retreats up the valley, it is left with very steep and a wide, flat floor. A river or stream may remain in the valley. This replaces the original stream or river and is known as a misfit stream because of its size. The river is expected to be bigger due to the sheer size of the valley.

Answer 2

Glaciers begin to form when snow remains in the same area year-round, where enough snow accumulates to transform into ice. Each year, new layers of snow bury and compress the previous layers. This compression forces the snow to re-crystallize, forming grains similar in size and shape to grains of sugar. Gradually the grains grow larger and the air pockets between the grains get smaller, causing the snow to slowly compact and increase in density. After about two winters, the snow turns into firn-an intermediate state between snow and glacier ice. At this point, it is about half as dense as water. Over time, larger ice crystals become so compressed that any air pockets between them are very tiny. In very old glacier ice, crystals can reach several inches in length. For most glaciers ,this process takes over a hundred years.

Answer 3

Glaciers can only be formed in polar regions or on mountain tops. Snow accumulates in the same area where it remains all year. The snow freezes in layers. Every year with every snowfall the layers become encompassed with new snow which freezes and adheres to the previous layers. The snow compresses and recrystallizes to form small grains.The state between snow and glacier is called Firn.