[Mr. Lucky]

Except, much of that land mass is significantly below sea level; as much as 3,500 meters.

[GingisK]

That is a major chunk of the ice. It is more like an iceberg that got grounded on an underwater mountain range.

[GingisK]

The drawing seems to show it is in a large bowl with a rim that extends above the water level. The ice below has already been accounted for in current sea levels, hasn't it?

There is plenty of ice that would cause trouble if melted, but no where near as bad as they tell.