Iceberg as big as Adams, Arapahoe counties

Some months ago, we reported on a large chunk of ice shelf that was cracking and threatening to break off the Antarctic Peninsula and float out into the ocean. Now the European Space Agency is warning that there is only about three miles of ice left holding that chunk of ice in place.

Three miles might seem a lot, but the crack has grown to 124 miles long, so three miles is like that little string that held your baby tooth in when you were too scared to just yank.

And when this “tooth” comes out, it’s going to be quite a bit larger than a baby tooth.

ESA satellite measurements show that the iceberg that will result is going to be about 6,000 square kilometers, or 2,316 square miles, in area.

That means, if you wanted to store it on the Front Range, it would cover all of Arapahoe and Adams counties, and, if you also laid it over the city and county of Denver, there’d still be about 500 square kilometers left.

And the total thickness of this gigantic ice cube will average about 657 feet, about half the height of the Empire State Building, so that, if it does drift away from Antarctica and up towards the Falkland Islands, it -- or its pieces, if it breaks apart -- could become a serious hazard for ships.

There is some good news in this. Because this is part of the Larsen Ice Shelf, that means it’s already in the water around Antarctica.

It won’t fall into the water and raise the sea levels, because it’s already floating, and it won’t change sea levels when it melts for the same reason that, when ice cubes in a drink melt, it doesn’t make the glass overflow.

But that’s the good news.

The bad news is that the ice shelves around Antarctica act as blockages to keep the glaciers and ice rivers from sliding faster from the land into the ocean.

Once this enormous piece of shelf is gone, the remaining shelf will be that much weaker, and the enormous glaciers of Antarctica, already beginning to melt as the climate changes, will have less keeping them from falling into the ocean themselves, which would raise sea levels.