Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Scientists Find Active Volcano in Antarctica
01-21-2008, 10:23 PM,
#1
Scientists Find Active Volcano in Antarctica
Quote:n an article published Sunday on the Web site of <a title="Nature Geoscience Web site" href="http://www.nature.com/ngeo/index.html">the journal Nature Geoscience, Hugh F. J. Corr and David G. 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.

For Antarctica, "This is the first time we have seen a volcano beneath the ice sheet punch a hole through the ice sheet," Dr. Vaughan said.

Heat from a volcano could still be melting ice and contributing to the thinning and speeding up of the Pine Island Glacier, which passes nearby, but Dr. Vaughan doubted that it could be affecting other glaciers in West Antarctica, which have also thinned in recent years. Most glaciologists, including Dr. Vaughan, say that warmer ocean water is the primary cause.

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 over the subsequent 23 centuries.

Although out of sight, the layer showed up clearly in airborne radar surveys conducted over the region in 2004 and 2005 by American and British scientists. The reflected radio waves, over an elliptical area about 110 miles wide, were so strong that earlier radar surveys had mistakenly identified it as bedrock. Better radar techniques now can detect a second echo from the actual bedrock farther down.

The thickness of ice above the ash layer provided an estimate of the date of the eruption: 207 B.C., give or take 240 years. For a more precise date, Mr. Corr and Dr. Vaughan turned to previous observations from ice cores, which contained spikes in the concentration of acids, another byproduct of eruptions. Scientists knew that an eruption occurred around 325 B.C., plus or minus a few years, but did not know where the eruption occurred. "We're fairly confident this is the same eruption," Dr. Vaughan said.

Now, they know both time and place.

"It's probably within Alexander the Great's lifetime, but not more precise than that," Dr. Vaughan said.

The under-ice eruption was probably similar to one in Iceland in 2004. Although explosive, spewing ash more than seven miles in the air, the Iceland eruption was much less powerful than Mount St. Helens, the volcano in Washington State that blew off its peak in 1980.


http://www.nytimes.com/2008/01/21/world/21....html?ref=world
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
Bug Scientists Learn How to Re-Write Memories CharliePrime 0 815 12-16-2013, 03:40 PM
Last Post: CharliePrime
Video Russian scientists Draw Liquid Blood From Frozen Mammoth drummer 1 721 06-01-2013, 07:06 PM
Last Post: Watchdog
  Scientists Enhance Intelligence of Mice with Human Brain Cells Frank2 4 1,699 03-22-2013, 10:45 PM
Last Post: Frank2
  Record amounts of polar ice around Antarctica h3rm35 5 1,428 09-25-2012, 11:38 PM
Last Post: h3rm35
  IBM scientists take image of atomic bonds h3rm35 2 971 09-19-2012, 02:54 PM
Last Post: icosaface
  ‘Euthanasia Rollercoaster’ Hailed by Anti-Human Scientists Defendfreedom 2 764 02-27-2012, 02:07 PM
Last Post: Defendfreedom
  Scientists puzzled by giant whirlpools that have appeared in the Atlantic Ocean Solve et Coagula 5 2,321 04-20-2011, 08:12 AM
Last Post: Steroidal
  Scientists create technique to delete traumatic memories TriWooOx 5 1,526 11-04-2010, 12:46 AM
Last Post: rsol
  Scientists plan to record people's dreams TriWooOx 0 689 10-28-2010, 08:15 PM
Last Post: TriWooOx
  Scientists call for a global nuclear renaissance in new study nik 1 1,259 08-24-2010, 12:45 AM
Last Post: JazzRoc

Forum Jump:


Users browsing this thread: 1 Guest(s)