Ice, Bergs, Etc.

Ice comes in many shapes and sizes. As it forms, a thin sheet of ice called grease ice appears on the surface. It looks a bit like a grease slick. The ice thickens in areas to form small pancake shapes. As the small pancakes come together they form larger pancakes, and so on. Ultimately what forms is a network of large pancakes making up the pack ice. As the pack ice moves with the water pieces often hit each other creating small mountains of ice from the impact, a buckling effect. Often you will see in these buckled areas what is called blue ice. When ice forms from saltwater the salt seeps out into the water below so that what is left is freshwater-ice. When the light filters through the buckled areas the ice appears blue. Below are examples of the different types of ice you would see at sea in the Antarctic.

Grease ice and small pancake ice

Grease ice and small panckae ice

Grease ice and small pancake ice

Small pancake ice

Small pancake ice

Small and Medium pancake ice

Small and medium pancake ice

Small and medium pancake ice

Medium pancake ice

Medium pancake ice

Medium and large pancake ice starting to form pack ice

Medium and large pancake ice starting to form pack ice

Large pancake ice

Large pancake ice

Large pancake ice formed into pack ice

Large pancake ice formed into pack ice

Buckled edges of the pack ice with a tint of blue

Buckled edge of the pack ice with a tint of blue

Blue ice at the edge of the pack ice

Blue ice in a buckled area of the pack ice

When the icebreaker is moving ice is broken up and turned aside.

Cross section of ice showing its thickness and the different layers.

When large pieces of an ice shelf or a glacier break off into the sea icebergs are formed.

What you see above water is only a small part of the whole berg. Two-thirds of the berg remain underwater. The biggest iceberg on record was 208 miles by 60 miles, bigger than some small countries. Icebergs usually last several years before melting as they drift northward.

Go To Photos of the Ross Ice Shelf

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