The great Crackup

Picture this if you can: A chunk of ice that has been connected to an island in the northern reaches of Canada snaps off and starts drifting toward sea lanes in the Atlantic. Happens all the time? Not in this case. The ice "floe" is approximately 66 square Kilometers in area (for those of you who are metric deficient, that's equivalent to over ten square miles). Look on a map of the area in which you live and lay out a ten square mile chunk and you'll begin to see the enormity of this little nightmare.

Where this has happened is at Ellesmere island and it happened about 16 months ago. It broke away from land that scientists have estimated had been a connection for over 3000 years. The ice had been a shelf, i.e. ice that was floating on the sea but also part of ice on the island. When it broke off the resulting earth tremor was picked up by seismic monitors almost 500 miles away. Pictures of the collapse were picked up by satellites.

This breakup of an ice shelf is consistent with other cracks in ice shelves in the arctic and in the antarctic. Now there's plent of ice in both places so why should we be concerned with a few square mile of it? Well, this giant ice island will be a danger to shipping, number one. Number two is that this is going to melt eventually which will add some volume to the sea. That's notgoing to raise the sea level by a measurable amount but it will be a slight dilution of the salty sea water. Add the increasingly frequent calving of glaciers fronting the world's oceans and the rapidly disappearing glaciers from the mountains of the Earth and we have an enormous problem. Or many enormous problems.

Is this a consequence of global warming?

Does the sun rise in the morning?