GlaciersKaren MoralesMelizza Suarez

Milson Villapando

What are Glaciers?

Glaciers are large persistent body of ice that forms where the accumulation of snow exceeds its ablation (melting and sublimation) over many years.

How is it

Formed?

snow ice glaciers

How does itMove?

The sheer weight of a thick layer of ice and the fact that it deforms as a "plastic" material, combined with gravity's influence, causes glaciers to flow very slowly. Movement along the underside of a glacier is slower than movement at the top due to the friction created as it slides along the ground's surface.

Where is it

LOCATED?

Approximate Worldwide Area Covered by Glaciers square kilometers)

Antarctica 11,965,000 without iceshelves and ice rises)

Total glacier coverage is nearly 15,000,000 square kilometers, or a little less than the total area of the South American continent. The numbers listed do not include smaller glaciated polar islands or other small glaciated areas, which is why they do not add up to 15,000,000.)

Greenland 1,784,000

Canada 200,000

Central Asia 109,000

Russia 82,000

United States 75,000 including Alaska)

China and Tibet 33,000

South America 25,000

Iceland 11,260

Scandinavia 2,909

Alps 2,900

New Zealand 1,159

Mexico 11

Indonesia 7.5

Africa 10

TYPESof

Glaciers

Ice Sheets Ice Shelves

-enormous continental masses of glacial ice and snow expanding over 50,000 square kilometers

- occur when ice sheets extend over the sea, and float on the water. In thickness they range from a few hundred meters to over 1000 meters

Ice Caps Ice Streams & Outlet Glaciers

-miniature ice sheets, covering less than 50,000 square kilometers. They form primarily in polar and sub-polar regions that are relatively flat and high in elevation.

-channelized glaciers that flow more rapidly than the surrounding body of ice

Ice fields Mountain Glaciers

- similar to ice caps, except that their flow is influenced by the underlying topography, and they are typically smaller than ice caps.

- develop in high mountainous regions, often flowing out of ice fields that span several peaks or even a mountain range.

Valley Glaciers Piedmont Glaciers

-commonly originating from mountain glaciers or ice fields, these glaciers spill down valleys, looking much like giant tongues. -may be very long, often flowing down beyond the snow line, sometimes reaching sea level.

-occur when steep valley glaciers spill into relatively flat plains, where they spread out into bulb-like lobes.

Cirque Glaciers Hanging Glaciers

-found high on mountainsides and tend to be wide rather than long.-named for the bowl-like hollows they occupy.

-also called ice aprons, these glaciers cling to steep mountainsides.

Tidewater Glaciers

-valley glaciers that flow far enough to reach out into the sea.-responsible for calving numerous small icebergs.

How do Glaciers

Affect Land?

•Glacial Erosion•Formation of Glacial Landforms

How do Glaciers

Affect People?

•provides drinking water•irrigates crops•help generate Hydroelectric Power

AreGlaciers

DANGEROUS?

•floods

•avalanches

•threat of icebergs

Glaciers &

Climate Change

Facts about Glaciers

Muir Glacier, located in Glacier Bay, Alaska, photographed by W. Field in Aug. 1941 (left) and B. Molnia in Sep. 1976 (middle) and Aug. 2004 (right). Note how the glacier has retreated and exposed rock in 1976 that has since become lush vegetation in 2004.

The Larsen Ice Shelf in Antarctica, March 21, 1998. Taken at the beginning of the Antarctic winter, the ice shelf is clearly visible. Notice that sea ice is forming over the ocean to the right the ice shelf. 

The massive lobe of Malaspina Glacier is clearly visible in this photograph taken from a Space Shuttle flight in 1989. Agassiz Glacier is to the left of Malaspina Glacier, and towards the top of the photograph Seward Ice Field is just visible.

Retreating mountain glaciers in Bhutan. This satellite image shows the termini of several glaciers in the Himalayan mountains of Bhutan. The glaciers have been receding over the past few decades, and lakes have formed on the surfaces and near the termini of many of the glaciers.

Glacier at the head of Canon Fiord, Ellesmere Island, Canada