Between the Arctic and the Atlantic Ocean lies the largest island in the world at 810,000 square miles. The terrain is an icy expanse; all of the land is covered by an icecap gradually sloping upward, except for its narrow, mountainous, rocky coast. That ice is over 100,000 years old and extends almost 2 miles underground. It is so massive that its weight presses the bedrock of this island below sea level.
To give you an idea of the magnitude of this degree of ice coverage, only recently was it discovered that this island has a Grand Canyon and geologically, may even be three separate islands. Of course, this is all covered by ice, or at least it was.
If all of the ice on Greenland melted today, it would cause sea level to rise 24 feet. This would erode 440,000 square miles of land along the coastlines of the world and displace about 375 million people. Effectively, wiping out major cities like Shanghai, New York, Charleston, and essentially the whole southern tip of Florida (Miami, Pembroke Pines, St. Petersburg, Coral Springs, etc.). Read More at Ricochet Science