Arctic lake melts out of sea ice into ocean

Something unusual is going on in the Beaufort Sea, a remote part of the Arctic Ocean north of Alaska. Over the past six weeks, a huge "lake" bigger than the state of Indiana has melted out of the sea ice.

Within the past week, this "polynya" - a Russian word for any open water surrounded by sea ice - finally melted through a part of the ice that separated it from the open ocean, forming a kind of bay in the planet's northern ice cap.

"The reason we're tracking it is because we had never seen anything like that before," said Mark C. Serreze, senior research scientist at the National Snow and Ice Data Center in Boulder, Colo.