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Glaciers and their Features

There are many features of a Glacier that are significant. Glaciers are large masses of ice that travel in a body of water very slowly. When they travel, they pick up materials that they drag up underneath. They create features such as Valleys and other land-form changes. They can also break up and create another feature, Icebergs. Ice bergs are extremely dangerous because only approximately 10% of the Iceberg shows on the surface. Unsuspecting ships can crash into them and cause extreme damage (ie: Titanic tragedy).

Crevasses are formed the tremendous force of the movement of the glacier causes it to deform and ope huge cracks in the ice which can make travelling across a glacier extremely dangerous. On the bottom of a glacier, large amounts of rock and soil are ground up by the massive weight of the glacier.

Moraines are long, dark bands visible on the top and edges of a glacier that are created when the glacier pushes or carries along the rocks and soil it moves. Medial moraines run down the middle of a glacier while lateral moraines are along the sides and terminal moraines are found at the terminus. When a glacier sometimes flows into another, moraines can also be created from that. The crevasses and moraines help scientists decide wheter or not an ice mass is a true glacier.

Glaciers also create many interesting features:

Glacial Valleys, are among the most common feaure created by a Glacier. They create large steep valleys with usually steep vertical cliffs, and are trough-shaped.

Fiords, glaciated valleys, and horns are all erosional types of landforms, created when a glacier cuts away at the landscape. Another type of glacial landform is created by deposition, or what a glacier leaves as it retreats or melts away. An eroded moraine juts above the landscape in the Rhone Valley, Switzerland. Giant boulders stud some of the pinnacles, left behind by a retreating glacier. A small tunnel has been cut through the moraine, seen at the center of the photograph. (H.F. Reid Collection, 1902, at the WDC-A for Glaciology, University of Colorado, Boulder, Colorado.)


Till is material that is deposited as glaciers retreat, leaving behind mounds of gravel, small rocks, sand and mud. It is made from the rock and soil ground up beneath the glacier as it moves. Glacial till can form excellent soil for farmland.

Material a glacier picks up or pushes as it moves form moraines along the surface and sides of the glacier. As a glacier retreats, the ice literally melts away from underneath the moraines, so they leave long, narrow ridges that show where the glacier used to be. Glaciers don't always leave moraines behind, because sometimes the glacier's own meltwater carries the material away.

Streams flowing from glaciers often carry some of the rock and soil debris out with them. These streams deposit the debris as they flow. Consequently, after many years, small steep-sided mounds of soil and gravel begin to form adjacent to the glacier, called kames.

Kettle lakes form when a piece of glacier ice breaks off and becomes buried by glacial till or moraine deposits. Over time the ice melts, leaving a small depression in the land, filled with water. Kettle lakes are usually very small, and are more like ponds than lakes.

Glaciers leave behind anything they pick up along the way, and sometimes this includes huge rocks. Called erratic boulders, these rocks might seem a little out of place, which is true, because glaciers have literally moved them far away from their source before melting away.

Drumlins are long, streamlined tear-drop-shaped formations. They are created when a glacier deposits material as it is flowing and then moves over it. Because they are deposited and shaped by glacier movement, all the drumlins left by a particular glacier will face the same direction. Often, groups of several thousand drumlins are found in one place, looking very much like whalebacks when seen from above.

 

 

 

What Are Glaciers? | How are they formed? | What are they Made of? | Where can they be found? | Erosion | The Ice Age | Famous Glaciers | Features | Glaciers and People | Interesting Facts | Bibliography