Antarctic ice shelves and ice streams

I was encouraged to post these images by the one at the top of the sequence -- a fantastic new Radarsat image released by the Canadian Government within the last week.  Click on the image to enlarge.  Note that as far as ice velocities are concerned, in the interior of the East Antarctic ice sheet there are vast areas where the annual velocity is only about 1 m per year -- whereas on the coast, particularly on the ice shelves,  the velocity is over 1 km per year. 

On the big ice shelves (the Ross Ice Shelf and the Ronne /Filchner Ice Shelf) it's very difficult to see where the grounding line is, and in the two lower images (reproduced in monochrome) the big outlet glaciuers merge imperceptibly with the shelf ice.  But the patterns are impressive  -- big streams of ice with very few tributaries and little trace of a true dendritic pattern of subsidiary "feeder" troughs.  This is exactly what we see in images of the fjords of NW Iceland, for example......