The amount of ice flowing into the sea from large glaciers in southern Greenland has almost doubled in the last 10 years, possibly requiring scientists to increase estimates of how much the world's oceans could rise under the influence of global warming, according to a study being published today in the journal Science.
The study said there was evidence that the rise in flows would soon spread to glaciers farther north in Greenland, which is covered with an ancient ice sheet nearly two miles thick in places, and which holds enough water to raise global sea levels 20 feet or more should it all flow into the ocean.
The study compared various satellite measurements of the creeping ice in 1996, 2000 and 2005, and was done by researchers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the University of Kansas.
Glaciers are creeping rivers of ice that accelerate or slow and grow thicker or shrink depending on the interplay of a variety of conditions including rates of snowfall and temperature and whether water lubricates the interface between ice and the rock below.
Sometimes the rate of movement in a particular glacier can change abruptly, but the speedup in Greenland has been detected simultaneously in many glaciers, said Eric J. Rignot, the study's author, who has extensively studied glacier flows at both ends of the earth.
"When you have this widespread behavior of the glaciers, where they all speed up, it's clearly a climate signal," he said in an interview. "The fact that this has been going on now over 10 years in southern Greenland suggests this is not a short-lived phenomenon."
Richard B. Alley, an expert on Greenland's ice at Pennsylvania State University who did not participate in the study, agreed that the speedup of glaciers in various places supported the idea that this was an important new trend and not some fluke.
"There's no way that the Jakobshavn Glacier on the west side can call up the Helheim on the other side of the ice sheet and say, 'Let's get going,' " he said.
A separate commentary published in Science by Julian A. Dowdeswell of the Scott Polar Research Institute in Britain noted that the rising flows could be a result of both the rapid deterioration of the miles of floating "tongues" of ice where the glaciers enter the sea and an increase in water melting on the ice surface and percolating down through crevasses, where it can reduce friction with the underlying rock.
Scoring disabled. You must be logged in to score posts.
Re: Glaciers Flow to Sea at a Faster Pace, Study Says
No score for this post
February 22 2006, 9:41 PM
We should dam them and put in hydro plants.
Then put in bottling plants and ship the bottled water. There is a lot of water going to waste there. One of the great things about humans drinking this water from the Arctic is when the urine returns to the ocean it will restore the natural salinity, one of the major issues regarding the melting ice caps.
Scoring disabled. You must be logged in to score posts.
You're a very funny person, Jo Jo. But one of the things that most alarms me about this whole issue is how people living in the industrialized world use the artificial environment they have built around themselves as a kind of shield against reality.
However witty you may be, and you are very witty, the glaciers are still flowing faster, and the ice sheet on Greenland is still steadily becoming more unstable. And if you live anywhere in the North Atlantic, and we get a major ice fall from Greenland into the ocean, you are going to be very witty and very wet.
Keep laughing, Jo Jo.
Conor
Scoring disabled. You must be logged in to score posts.
You're a very funny person, Jo Jo. But one of the things that most alarms me about this whole issue is how people living in the industrialized world use the artificial environment they have built around themselves as a kind of shield against reality.
However witty you may be, and you are very witty, the glaciers are still flowing faster, and the ice sheet on Greenland is still steadily becoming more unstable. And if you live anywhere in the North Atlantic, and we get a major ice fall from Greenland into the ocean, you are going to be very witty and very wet.
