Another MODIS image taken from NASA's Terra Satellite on January 24, 2008 (top) and January 30, 2008.
The top image of the Antarctic Peninsula showed the fast ice (ice anchored to the land) looking solidly frozen but over the next few days the ice's blue hue changed.
Blue ice is pure ice composed of relatively large crystals. Ice absorbs a tiny amount of red light which makes blue and green light reflect off the surface. The red-absorption is obvious in pure ice because of those large crystals than it is in tiny snow crystals which appear white.
The blue indicates that temperatures have warmed enough to melt the upper snow layer and a thin film of water might also be resting on the surface.
While the change in these images looks dramatic, the summer thaw, which usually begins in early to mid-December, was delayed by the 2007 La Nina causing unusually cold temperatures so this area remained solidly frozen into January 2008