Sunday, July 21, 2013

Greenland ice sheet, melting at Ilulissat .. by gimleteye

In Ilulissat, traveling by boat among the icebergs flooding out of the Kanja glacier gives one plenty of time to think about what is happening here. The landscape of ice is constantly changing as the ice moves, and splits under the titanic forces of nature. The ice that you scoop down to pick up could have been formed, our guide says, anywhere from 10,000 to over 100,000 years ago. It melts, drips and disappears through your fingers. We sail among the icebergs looking for calving events. Our guide tells us, the harbor hasn't frozen over completely the past few years. In the midnight sun the dog sleds are stacked on the land where they were last used. Everyone is talking about the warmer weather and wondering what comes next. It is ninety seven degrees in New York City, today, and it is relatively warm here too.

In the powerpoint presentation given by Dr. Harold Wanless, chairman of the Department of Geologic Sciences at the University of Miami, there is one slide that shows the bottom contour of the Kanja fiord. Dr. Wanless' core samples of sea water bottom reveal a past history of sea level rise that defy the common logic of linear, small increases over time. The geologic record shows that sea level rise occurs over time, in a series of rapid pulses. One likely explanation is what is happening under the Kanja fiord, where a shelf, several hundred meters high, effectively blocks the path of the largest pieces of the glacial icebergs. The theory is that eventually, under massive pressure of moving ice, this underwater shelf bursts open, releasing a torrent of ice.

The megacities of China and India, of Western Europe and the Americas, are combusting fossil fuels and changing the planet. The gases from livestock to feed the world's billions are changing the planet. The melting permafrost, releasing vast stored methane gas, is changing the planet. Whether our coastal cities survive might depend on a granite shelf beneath the Kanja ford only a few hundred meters high. I am in Ilulissat, one more day.


Anonymous said...

In the last pic I can see Lynda Bell's face!

Anonymous said...

I envy you