We have frequently heard about the term glaciers. What are glaciers? Glaciers are huge mass of ice which flows slowly towards the land. Glaciers form in high mountain ranges and in the cold polar areas. Due to the extreme low temperatures in these regions, snow get accumulated and layers and layers of snow over years turns into ice. Glaciers vary in depth/thickness from 300 to 10,000 feet.
Glaciers are primarily of two types. The first type, the continental glaciers are found in the polar regions and these are extremely thick sheets of ice which spread over vast regions and practically conceal the landscape below them excepting the high peaks. They build up in their centers and slope gradually outward towards the sea on every direction. The second type are the valley glaciers which are narrow and long sheets of ice that slide down high mountain valleys. They generally originate from bowl shaped hollows which are formed in the peaks and gradually slope down from them.
How are glaciers formed: During winter season, when there is heavy snowfall, snow does not melt in equal proportions as it does during hotter weather. Since there is consistent snowfall during winter season, layers of snow gets accumulated one on top of the other. The increasing weight of the layers converts the snow crystals under the lower surfaces to become grain like pellets and more compact. When the snow layer reaches a depth more or less fifty feet, the pellets gets more compressed and converts themselves into dense ice crystals. Further, these ice crystals fuse together to form glacial ice. Due to this accumulation factor, the ice layers gain so much weight by itself that it begins to move under its own pressure.
Glaciers are greatly affected by seasonal changes. During winter season, as there is consistent snow fall and no melting of ice due to low temperatures, glaciers grow in size. In regions away from the poles, the glaciers decrease in size during summer due to melting and increased temperatures. Glaciers found in the polar region’s decrease in size due to various other reasons. When the flowing glaciers reach the sea, ice chunks break away from these glaciers forming icebergs. Glaciers size is also greatly affected by climatic changes affecting our world due to green-house gases. The climate is getting hotter and the temperatures are gradually rising. This is having a great impact on the glaciers around the world.