Environment

Large Hole Opens in Antarctica Ice

A mysterious hole as big as the state of Maine has been spotted in Antarctica’s winter sea ice cover. The hole was discovered by researchers about a month ago.

Known as a polynya, this year’s hole was about 30,000 square miles at its largest, making it the biggest polynya observed in Antarctica’s Weddell Sea since the 1970s.

The harsh winter in Antarctica makes it hard to find holes like this one, so it can be difficult to study them. This is the second year that a polynya formed, though last year’s hole was not as big.

The deep water in that part of the Southern Ocean is warmer and saltier than the surface water. Ocean currents bring the warmer water upwards, where it melts the blankets of ice that had formed on the ocean’s surface. That melting created the polynya.

The blue curves represent the ice edge, and the polynya is the dark region of open water within the ice pack.