Ice

Volcano under Antarctic ice may erupt, accelerate melting

Publication: NBC News   Date: November 17, 2013   View Article

A newly discovered volcano rumbling beneath nearly a mile of ice in Antarctica will almost certainly erupt at some point in the future, according to a new study. Such an event could accelerate the flow of ice into the sea and push up the already rising global sea levels.

When the volcano will blow is unknown, “but it is quite likely” to happen, Amanda Lough, a graduate student in seismology at Washington University in St. Louis, Mo., told NBC News.

Message from the mud: East Antarctic meltdown could cause massive sea rise

Publication: NBC News   Date: July 21, 2013   View Article

The last time concentrations of the greenhouse gas carbon dioxide were as high as they are today, big chunks of the seemingly stable East Antarctic ice sheet melted and helped raise global sea levels more than 65 feet higher than they are now, a new study suggests.

Scientists have long known that seas were higher during the Pliocene, a geological epoch that ran from 5.3 million to 2.6 million years ago. At the time, atmospheric carbon dioxide levels were similar to today’s 400 parts per million (ppm).

“Overall, it was a warmer climate than today, but similar to what we expect to reach by the end of this century,”Carys Cook, a graduate student at the Grantham Institute for Climate Change at Imperial College London and the study’s lead author, told NBC News in an email.

Ice-free Arctic in our future, ancient climate record suggests

Publication: NBC News   Date: May 9, 2013   View Article

About 3 million years ago, evergreen forests — not tundra — carpeted the Arctic, Greenland was green, and sea ice only formed for a few months in the winter, if it formed at all, according to analysis of sediment pulled from a Russian lake.

“Where we are going is into this warmer world,” Julie Brigham-Grette, a geologist at the University of Massachusetts Amherst, told NBC News.

At the time — the Pliocene — concentrations of the greenhouse gas carbon dioxide were around 400 parts per million, the same as they are today. But Arctic temperatures were about 14.4 degrees Fahrenheit (8 degrees Celsius) warmer than today, explained Brigham-Grette, who led the analysis.

Chill out? Greenland glaciers’ acceleration to slow, study says

Publication: NBC News   Date: May 8, 2013   View Article

For the past ten years, skyscraper-sized icebergs have cracked off glaciers in Greenland and tumbled into the sea at an ever-quickening rate in response to global warming, raising concerns about runaway ice loss and rising seas. The good news? The rate of acceleration will slow, according to a new study.

The slowdown is related to the physics and geography that govern glacier movement, not a forecast that the rise in global temperatures will halt anytime soon. Indeed, the ice sheets will continue to melt and push up sea levels around the world, just not as quickly as feared, the study’s lead author said.

Global warming to open ‘crazy’ shipping routes across Arctic

Publication: NBC News   Date: March 4, 2013   View Article

By the middle of this century, thanks to climate change, anyone with a light icebreaker can spend their Septembers going anywhere they want in the Arctic Ocean, including straight over the North Pole, according to a new study.

Ordinary vessels, which account for more than 99 percent of shipping traffic, could easily navigate the Northern Sea Route along the Russian coastline and, in some years, even find a route through the fabled Northwest Passage.

“That’s kind of crazy and, frankly, a little bit worrisome,” Laurence C. Smith, a geographer and sea ice expert at the University of California, Los Angeles, told NBC News. “It is not like these will be open blue seas and safe or open year round.”

Hawaii to suffer most as global sea levels rise, study says

Publication: NBC News   Date: February 21, 2013   View Article

Melting ice in Greenland, Antarctica and elsewhere will push up seas unevenly around the world, according to a new study that finds some of the highest waters will inundate Honolulu, Hawaii.

At the poles, sea levels will actually fall because of the way sea, land and ice interact. For example, the sheer mass of water held in ice in Greenland and Antarctica generates a gravitational field that pulls in the surrounding water. As ice there melts, the gravitational pull weakens and the water is redistributed.

Is Arctic ice thinning?

Publication: msnbc.com   Date: June 22, 2011   View Article

Scientists have long used satellite imagery to illustrate the shrinking extent of the Arctic sea ice. Now they’ve got satellite data that will provide regular updates on whether the ice is getting thinner as well.

The first ice thickness map from the European Space Agency’s CryoSat spacecraft was released Tuesday at an air show in Paris. It was compiled with data collected in January and February.

The map shows, for example, the ice is thickest near the North Pole and off the coasts of Greenland and northeastern Canada. It thins as it stretches out towards Alaska and Russia.

© 2008-2010 Collected Writings By John Roach