More Evidence Needed

 A citation from LiveScience.com informs us that,

"Dotson Ice Shelf is a 30-mile-wide (50 km) chunk of floating ice seven times the size of New York City, located on the coast of Marie Byrd Land in West Antarctica. It is part of the West Antarctic ice sheet, which has dramatically calving glaciers that could cause sea levels to rise by approximately 11 feet (3.4 m) if they eventually drive the entire sheet to collapse."

Since the ice shelf is presently floating in the ocean, the melting (or collapse) of the entire thing will not raise sea level by a single inch. Floating ice displaces precisely as much water as the weight of the ice, so when it melts, it leaves the water level unchanged. You can test this by putting some ice cubes in a glass of water and observing what happens to the water level when the ice cubes melt.

There is a theory, not mentioned in this article, that ice shelves serve to block the advance of glaciers, so if they are removed the glacier will advance quickly into the ocean and raise sea level rapidly and by great amounts. I have searched for any explanation or actual evidence which would back up this theory and have never found any.