 |
Featured Articles
|
|
|
 |
|
|
|
|
|
|
|
Current Articles
|
|
|
|
|
|
|
|
|
|
|
|
News Articles Archive
|
|
|
|
|
|
 |
|
|
|
| Earth's Core, Magnetic Field Changing Fast |
319 Views |
| posted on Sunday, July 06, 2008 |
|
|
EARTH'S CORE, MAGNETIC FIELD CHANGING FAST, STUDY SAYS
By Kimberly Johnson
National Geographic News
June 30, 2008
Original Link
Rapid changes in the churning movement of Earth's liquid outer core are weakening the magnetic field in some regions of the planet's surface, a new study says.
"What is so surprising is that rapid, almost sudden, changes take place in the Earth's magnetic field," said study co-author Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen.
The findings suggest similarly quick changes are simultaneously occurring in the liquid metal, 1,900 miles (3,000 kilometers) below the surface, he said.
The swirling flow of molten iron and nickel around Earth's solid center triggers an electrical current, which generates the planet's magnetic field.
The study, published recently in Nature Geoscience, modeled Earth's magnetic field using nine years of highly accurate satellite data.
Flip-Flop
Fluctuations in the magnetic field have occurred in several far-flung regions of Earth, the researchers found.
In 2003 scientists found pronounced changes in the magnetic field in the Australasian region. In 2004, however, the changes were focused on Southern Africa.
The changes "may suggest the possibility of an upcoming reversal of the geomagnetic field," said study co-author Mioara Mandea, a scientist at the German Research Centre for Geosciences in Potsdam.
Earth's magnetic field has reversed hundreds of times over the past billion years, and the process could take thousands of years to complete.
Upper Atmosphere Radiation
The decline in the magnetic field also is opening Earth's upper atmosphere to intense charged particle radiation, scientists say.
Satellite data show the geomagnetic field decreasing in the South Atlantic region, Mandea said, adding that an oval-shaped area east of Brazil is significantly weaker than similar latitudes in other parts of the world.
"It is in this region that the shielding effect of the magnetic field is severely reduced, thus allowing high energy particles of the hard radiation belt to penetrate deep into the upper atmosphere to altitudes below a hundred kilometers (62 miles)," Mandea said.
This radiation does not influence temperatures on Earth. The particles, however, do affect technical and radio equipment and can damage electronic equipment on satellites and airplanes, Olsen of the Danish space center said.
Keep Watching
The study documents just how rapidly the flow in Earth's core is changing, said Peter Olson, a geophysics professor at Johns Hopkins University in Baltimore, Maryland, who was not involved with the research.
By using satellite imagery, researchers have a nearly continuous measurement of changes, he said.
"They provide a good rationale to continue this monitoring longer," Olson said.
------------
PREVIOUS NHNE NEWS LIST ARTICLES:
THE DAY THE EARTH FELL OVER (9/15/2006):
http://groups.yahoo.com/group/nhnenews/message/11857
SCI FI CHANNEL: COUNTDOWN TO DOOMSDAY (6/11/2006):
http://groups.yahoo.com/group/nhnenews/message/11369
EARTH'S MAGNETIC FIELD FLIPS QUICKLY (4/9/2004):
http://groups.yahoo.com/group/nhnenews/message/7055
NOVA'S 'MAGNETIC STORM' (11/28/2003):
http://groups.yahoo.com/group/nhnenews/message/6322
The Earth's Collapsing Magnetic Field (8/9/2003):
http://groups.yahoo.com/group/nhnenews/message/5772
MORE ON THE EARTH'S FLIPPING MAGNETIC POLES (11/14/2002):
http://groups.yahoo.com/group/nhnenews/message/3950
SUN'S RAYS TO ROAST EARTH AS POLES FLIP (11/13/2002):
http://groups.yahoo.com/group/nhnenews/message/3948
EARTH'S MAGNETIC FIELD ABOUT TO FLIP? (7/8/2002):
http://groups.yahoo.com/group/nhnenews/message/3376
GIANT NUKE MAY RUN EARTH'S MAGNETIC FIELD (6/22/2002):
http://groups.yahoo.com/group/nhnenews/message/3294
EARTH'S MAGNETIC POLES MAY BE STARTING TO FLIP (4/12/2002):
http://groups.yahoo.com/group/nhnenews/message/2990
|
|
 |
|
|
|
|
|
|
|
............
In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. Unless the information in question has been written and/or published by NHNE, NHNE has no affiliation whatsoever with the originator of this article. NHNE is, therefore, not endorsed or sponsored by the originator, nor does NHNE necessarily endorse, promote, or agree with the content. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner.
|
|
|
|