Sea Ice and IcebergsQuestions

Question 1

[True/False] In recent years, the thickness and extent of sea ice has been decreasing.

The correct answer is True.

Over the past 30 years, the summer minimum sea ice has decreased by over 10% per decade. Long-term climate models indicate entirely ice-free summers by the end of this century.

Question 2

Use the selection boxes to choose the answers that best complete the statements.

Over short periods, sea ice drift is controlled by , while over longer periods it is controlled by .

The correct answer is that over short periods, sea ice drift is controlled by wind, while over longer periods it is controlled by currents.

Question 3

Use the selection boxes to choose the answers that best complete the statements.

Compared to sea ice, icebergs tend to be and .

The correct answer is that compared to sea ice, icebergs tend to be stronger and thicker. Icebergs are formed when ice calves off glaciers formed on land. The ice is very fresh (thus strong) and can be quite thick.

Question 4

Where do most Arctic icebergs form? (Choose the best answer.)

The correct answer is c) "Greenland."

Icebergs from Greenland follow currents around Baffin bay, then south to the Grand Banks and North Atlantic shipping lanes.