A rapidly-growing crack in the fourth-largest ice shelf in Antarctica has scientists watching for it to break off entirely. By early February, the crack in the Larsen C ice shelf was more than 100 miles long and some parts of it were 2 miles wide. In the two-month period between December and February, the crack grew by 17 miles, a pace of about five football fields a day.
This time of the year, sea ice in the Arctic is on the rise as winter sets in. A combination of unusually high air temperatures and a warmer than normal ocean led to a record low for Arctic sea ice extent in November. In the Southern Hemisphere, Antarctic sea ice extent also hit a record low for the month.
