Area per extent ratio using real data from a single consistent source: http://deponie.bplaced.net/arctic/rat.svg This is calculated using the IUP Bremen GeoTIFF files and pixel area data from NSIDC. Missing data are interpolated up to a 13-day gap and filled by persistence up to 7 days. Pixels around the pole that were ever undefined are always counted as 100%; remaining missing data (very few) too. Data includes lakes. I also removed every pixel that is less than 12.5 km away from a land pixel to remove most of the spurious coastal ice. 2007 had more such spurious ice and that's the reason that 2011 is at 2007 level in IUP Bremen graphs. Extent: http://deponie.bplaced.net/arctic/ext.svg Area: http://deponie.bplaced.net/arctic/area.svg To compare, same without coasts masked out: Ratio: http://deponie.bplaced.net/arctic/ratc.svg Extent: http://deponie.bplaced.net/arctic/extc.svg Area: http://deponie.bplaced.net/arctic/areac.svg Current data with marked coasts: http://deponie.bplaced.net/arctic/2011-08-21.png Coast and pixels ever undefined after interpolation and persistence (marked red): http://deponie.bplaced.net/arctic/mask.png

The fractured part is mostly first year ice that formed after the ice bridge had been established. http://ice-glaces.ec.gc.ca/prods/WIS55CT/20110613180000_WIS55CT_0005856255.gif Note that the map (from Monday) already shows some mobile ice in SE Kennedy Channel. However, it may take several weeks until all of Nares Strait has fractured. NAIS forecast from Thursday says: "Near mid-July, some of the fracture events will occur over Pond Inlet, in northern Admiralty Inlet, in western Barrow Strait and in Kane Basin." http://ice-glaces.ec.gc.ca/prods/FECN16G/20110616000000_FECN16G_0005858072.pdf The map, valid 2011-07-15, shows mobile ice all along Nares Strait, but just bergy water south of it, meaning no ice transport. The seasonal forecast had complete fracture of Kane Basin around 16-18 July. http://ice-glaces.ec.gc.ca/prods/ARCTIC001/20110602000000_ARCTIC001_0005834825.pdf Weather forecast for the next week suggests little clouds, much radiation, rather high temperatures and even moderate winds at some days. But spring was quite cold and ice that has been consolidated for months won't collapse easily. http://deponie.bplaced.net/arctic/gfs.2011-06-18.12z/