If you thought you were melting over the summer, just be glad you're not an ice sheet that's been chilling out since before Europeans settled in Canada. Over the summer, two huge Canadian ice shelves in the Arctic shrunk down precipitously, report scientists from the University of Ottawa and Carleton University. One sheet had already split into two sections and just kept getting smaller; the other broke in half this year. Icebergs are breaking away and "pose a risk to offshore oil facilities and potentially to shipping lanes," reports the Associated Press. "Since the end of July, pieces equaling one and a half times to the size of Manhattan Island have broken off."

This is not normal behavior for an ice shelf this large and old, says the AP:

[Professsor Luke] Copland said those two losses are significant, especially since the Ward Hunt Ice Shelf has always been the biggest, the farthest north and the one scientists thought might have been the most stable.

Climate change may be opening the mythic Arctic passage but — OOPS, HAD TO DODGE AN ICEBERG — it doesn't seem like much of a trade off when there are Manhattan-sized ice chunks floating around.

Grist thanks its sponsors. Become one.