The youtube link is broken in post #1 of this forum, Helheim Glacier calving by Hans Henrik Tholstrup. The link is now
I came across a 2001-2005 time series that was interpreted as a retreat progressionhttp://earthobservatory.nasa.gov/IOTD/view.php?id=6207&eocn=image&eoci=related_image
Howat, I. M., I. Joughin, S. Tulaczyk, and S. Gogineni (2005). Rapid retreat and acceleration of Helheim Glacier, east Greenland. Geophysical Research Letters, 32, L22502, http://onlinelibrary.wiley.com/doi/10.1029/2005GL024737/full
(free full text)
A significant amount of the measured coastal thinning of the Greenland ice sheet may be due to recent acceleration of outlet glaciers. Using remote sensing, we measured two major periods of speedup on Helheim Glacier between 2000 and 2005 that increased peak speeds from approximately 8 to 11 km/yr. These speedups coincided with rapid retreats of the calving front, totaling over 7.5 km. The glacier also thinned by over 40 m from 2001 to 2003. Retreat of the ice front appears to decrease resistance to flow and concentrates the gravitational driving force over a smaller area. Farther up-glacier, acceleration may be a delayed response to surface draw-down and steepening of the glacier's main trunk. If the 2005 speedup also produces strong thinning, then much of the glacier's main trunk may un-ground, leading to further retreat.