It looks like the ice arch in at the southern end of Nares Strait has started to collapse, according to yesterday's satellite image from LANCE-MODIS:
This break-up is occuring 10 days later than last year. Back then it took about two weeks for all of the ice to start moving across the entire strait and transport from the Lincoln Sea to get underway. Looking at the weather forecasts and the fact the ice is blue and breaking up at the other side as well, I don't think it will take much longer. High time too, as Baffin Bay has almost run out of ice.
But if you want to know the real deal about Nares Strait, I urge you to go to the Icy Seas blog. This blog is run by sea-going physical oceanographer Andreas Münchow, who has actually been to Nares Strait and will soon go back there to retrieve all kinds of gadgets full of data on ice thickness, volume flux and what not. He graciously allows me to re-post his latest blog post:
Nares Strait 2012 Ice Arch Collapsing
The collapse of the ice-arch in southern Nares Strait began June-27, 2012 with development of a small hairline fracture along the western side of the strait off Ellesmere Island, Canada. The fracture connects an isolated area of open water off Bache Peninsula, Canada at 79 N latitude. The front between land-fast ice in the north and the open water in the south has moved slightly southward. It has also lost a visible larger piece of ice that before anchored the bridge at its western connection to land. This motion will open the hairline fracture more, accelerating the collapse of the ice-arch. The missing support of the ice-arch on its western side will collapse the entire ice-arch and the previously land-fast ice of Nares Strait will stream rapidly to the south, I predict, before this weekend.
Updates (including an animation) will be posted daily at http://muenchow.cms.udel.edu/Nares2012/Kane/.
Ice-bridge at southern Nares Strait June-26, 2012 23:30 UTC from MODIS-Terra. There are no hairline fractures yet along the Ellesmere Island side near 79 N latitude. Greenland is on the right (east), Canada on left (west).
Ice-Bridge at southern Nares Strait on June-27, 2012 17:40 UTC from MODIS-Terra. Notice the crack and hairline fractures in the ice along the Ellesmere Island coast near 79 N latitude and 75 W longitude.
This collapse happens each year in the summer, though the timing varies from April for weak and July for strong arches. The arch in 2012 lasted longer than the one in 2011. No or only weak ice-arches formed at this site in 2007, 2008, and 2009, e.g., http://muenchow.cms.udel.edu/MODIS/.
Read the whole thing and comments here.