The Markham ice shelf, previously located off of Ellesmere Island’s northern coast broke off early this August, reports Luke Copland, head of Cryospheric Research at the University of Ottawa. The 19 square mile ice mass, roughly the size of Manhattan, is now a free-floating island in the Arctic Ocean.

This may seem large, but it’s not the largest ice shelf to shake loose or disintegrate. In the summer of 2005, the 25 square mile Ayles Ice shelf suddenly broke off of Canada’s northern coast, and earlier this year, the Wilkins Ice Shelf which was previously located in the Antarctic broke away as well; this one was a massive 160 square miles. The amount of ice lost this year is alarming, and is second only to the previous year’s record losses.

The disintegration of the ice shelves destroys microbial habitat, and kills its unicellular inhabitants, which are an intrinsic part of the arctic food chain and also useful to biological research.

Although perhaps the most serious consequence may well be the deep impact on global warming: the breakup of the ice banks creates more open water which would give rise to autumn temperatures along arctic coasts over the next few years, which in turn will prolong the permafrost melt season, increasing the rate at which it releases enormous amounts of stored carbon as greenhouse gases like carbon dioxide or methane. As an aside, the free-floating ice masses pose danger to off-shore oil drilling platforms which could not withstand such tremendous impacts.

The changes going on are stunningly quick, and irreversible according to scientists. If they continue they could change the face of the planet in only a few decades.