Glaciers And Volcanoes Don’t Mix
Another factor might be contributing to the thinning of some of the Antarctica's glaciers: volcanoes.
In an article published Sunday on the Web site of the journal Nature Geoscience, Hugh Corr and David Vaughan of the British Antarctic Survey report the identification of a layer of volcanic ash and glass shards frozen within an ice sheet in western Antarctica.
"This is the first time we have seen a volcano beneath the ice sheet punch a hole through the ice sheet" in Antarctica, Vaughan said.
Volcanic heat could still be melting ice to water and contributing to thinning and speeding up of the Pine Island glacier, which passes nearby, but Vaughan said he doubted that it could be affecting other glaciers in western Antarctica, which have also thinned in recent years. Most glaciologists, including Vaughan, say that warmer ocean water is the primary cause of thinning.
Volcanically, Antarctica is a fairly quiet place. But sometime around 325 B.C., the researchers said, a hidden and still active volcano erupted, puncturing several hundred yards of ice above it. Ash and shards from the volcano carried through the air and settled onto the surrounding landscape. That layer is now out of sight, hidden beneath the snows that fell during the next 2,300 years.
I caught another article on this last night that had a very interesting tidbit:
Corr and Vaughan used ice-penetrating radar to locate the volcano just west of the expansive Pine Island Glacier. Specifically, they detected a New Jersey-sized plot of ash at more than 8,000 square miles (20,700 square kilometers) beneath the ice.
The debris is a hallmark of an ancient eruption.
“The discovery of a ‘subglacial’ volcanic eruption from beneath the Antarctic ice sheet is unique in itself," Corr said. "But our techniques also allow us to put a date on the eruption, determine how powerful it was and map out the area where ash fell."
Scientists like Corr have used radar and other technologies to find other features, such as lakes, tucked beneath the Antarctic ice. Researchers also think that magma-heated rock beneath Greenland's massive ice sheet is accelerating its melting, but whether a volcano or just a pool of magma is responsible is still a matter of debate.
New Jersey sized ash field and volcanic activity in Western Antarctica. Claims that the Western ice sheets are melting. Possible magma related melting in Greenland. Claims that the Greenland ice sheets are melting.
Note a pattern there?
Environment | Gaius January 21, 2008
Other Links to this Post
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The Icecaps Are Melting! The Icecaps Are Melting! « Tom’s Fireside Chat — January 22, 2008 @ 4:08 pm
By NortonPete, January 21, 2008 @ 7:04 pm
The existence of volcanic activity in these two regions makes sense.
Iceland has volcanic activity. Just think of the massive weight that these 5000 ft deep ice fields are exerting on the earth’s crust. There is an Antartic plate that must be under tremendous pressure.
By Tom, January 22, 2008 @ 3:57 pm
Where will the bears, seals, and penguins go?
Wonder if Algor has room at his mansion…