Glaciers erode the land in three primary ways: plucking, abrasion and freeze-thaw. All three manners of erosion combine to make glaciers one of the world’s most powerful agents of erosion.Continue Reading
Glaciers are essentially frozen rivers. They are common in the Northern Hemisphere as well as at high altitudes. Glaciers do not erode mountains and bedrock quickly, but over long periods, they cause drastic changes.
Glaciers usually have at least one side that is in contact with rock. When part of the glacier melts, it allows water to penetrate behind the glacier and pull broken rocks from the wall. This is called plucking. When the melted water near the top of the glacier repeatedly melts and freezes, the water forces its way into the cracks. When water freezes, it expands, causing the rock to break. This type of erosion is called freeze-thaw. Finally, when rocks stick to the glacier, they may rub against the bedrock, which is called abrasion.
Glaciers have carved a number of important geographic features. Glacier National Park features a number of valleys cut by ancient glaciers as well as glacially damaged mountains. A giant glacier carved the Matterhorn, a large sharp peak in Switzerland. Other times, glaciers break into small pieces and melt, which forms small lakes called kettle lakes.Learn more about Earth Science
Fresh water is turned into an iceberg by the splitting or calving of glaciers. Bergs also vary wildly in shape and can be steep or irregular with rounded or flat tops. Because wind and water erode them, they constantly shift shape.Full Answer >
Icebergs are formed from ice breaking off of glaciers or ice shelves. Fluctuating temperatures and seismic events can cause the breaks in these glaciers and ice shelves.Full Answer >
Continental and valley glaciers both develop in regions where there is constant snowfall and freezing temperatures throughout the year. Both types of glaciers move at a very slow pace.Full Answer >
Though rivers have flowed across what is now the Mississippi River basin for millions of years, the modern river emerged from the drainage of melting glaciers around 12,000 years ago. The Mississippi has shifted course continuously since then, and its course remains erratic and unpredictable.Full Answer >