MessageToEagle.com

Rapid Changes In The Earth's Core -
The Magnetic Field And Gravity Seen By Satellites

23 October, 2012

Share this story:
Follow us:

MessageToEagle.com - Rapid, almost sudden, changes take place in the Earth’s magnetic field.

A German-French group of geophysicists observed that - changes in the earth's magnetic field in a region stretching from the Atlantic to the Indian Ocean - have a close relationship with variations of gravity in this area.

From this it can be concluded that outer core processes are reflected in gravity data. This is the result presented by scientists in the latest issue of PNAS.

The main field of the Earth's magnetic field is generated by flows of liquid iron in the outer core. The Earth's magnetic field protects us from cosmic radiation particles.


Click on image to enlarge

http://www.pnas.org/content/suppl/2012/10/11/1207346109.DCSupplemental/pnas.1207346109_SI.pdf


Therefore, understanding the processes in the outer core is important to understand the terrestrial shield. Key to this are measurements of the geomagnetic field itself.
A second, independent access could be represented by the measurement of minute changes in gravity caused by the fact that the flow in the liquid Earth's core is associated with mass displacements.

The research group has now succeeded to provide the first evidence of such a connection of fluctuations in the Earth's gravity and magnetic field.



Click on image to enlarge

http://www.pnas.org/content/suppl/2012/10/11/1207346109.DCSupplemental/pnas.1207346109_SI.pdf


They used magnetic field measurements of the GFZ-satellite CHAMP and extremely accurate measurements of the Earth's gravity field derived from the GRACE mission, which is also under the auspices of the GFZ.

"The main problem was the separation of the individual components of the gravity data from the total signal," explains Vincent Lesur from the GFZ German Research Centre for Geosciences, who is involved in the study.


Simulated three-dimensional structure of Earth's magnetic field, with inward (blue) and outward (yellow) directed field lines. Field lines extend two Earth radii from the core. The location of the core-mantle boundary is evident where the structure becomes complex. Credits: G. Glatzmaier, Los Alamos National Laboratory. P. Roberts, University of California-Los Angeles


A satellite only measures the total gravity, which consists of the mass fractions of Earth's body, water and ice on the ground and in the air. To determine the mass redistribution by flows in the outer core, the thus attained share of the total gravity needs to be filtered out.


Cutaway views showing the internal structure of the Earth. Left: This scale drawing shows that the Earth's crust is literally only skin deep. Right: A view not drawn to scale showing the Earth's three main layers (crust, mantle, and core) in more detail.


"Similarly, in order to capture the smaller changes in the outer core, the proportion of the magnetic crust and the proportion of the ionosphere and magnetosphere need to be filtered out from the total magnetic field signal measured by the satellite," Vincent Lesur explains. The data records of the GFZ-satellite missions CHAMP and GRACE enabled this for the first time.

During the investigation, the team focused on an area between the Atlantic and the Indian Ocean, as the determined currents flows were the highest here. Extremely fast changes (so-called magnetic jerks) were observed in the year 2007 at the Earth's surface. These are an indication for sudden changes of liquid flows in the upper outer core and are important for understanding the magneto-hydrodynamics in the Earth's core.

Using the satellite data, a clear signal of gravity data from the Earth's core could be received for the first time.

This results in consequences for the existing conceptual models. Until now, for example, it was assumed that the differences in the density of the molten iron in the earth's core are not large enough to generate a measurable signal in the earth's gravitational field. The newly determined mass flows in the upper outer core allow a new approach to Earth's core hydrodynamics.

“Recent changes of the Earth’s core derived from satellite observations of magnetic and gravity fields”, Mioara Mandea, Isabelle Panet, Vincent Lesur, Olivier de Viron, Michel Diament, and Jean-Louis Le Mouël,

Study published in PNAS 2012; doi:10.1073/pnas.1207346109.

MessageToEagle.com

See also:
Strange Red Appearance Of Azov Sea - Locals Panic

Exploding Lakes - Horrifying Natural Phenomena

Follow MessageToEagle.com for the latest news on Facebook and Twitter !

Don't Miss Our Stories! Get Our Daily Email Newsletter

Enter your email address:


Once you have confirmed your email address, you will be subscribed to the newsletter.

Recommend this article:


Odd Phenomenon Of The Red Rocks - Why Did All The Stones Suddenly Change Color?

Some years ago, back in, 2005, over the slopes of Mount Gongga, China all rocks suddenly turned red. In time, the entire region became known the "Red-Stone-Valley" and today it is a spectacular local tourist attraction. For many years, scientists have wondered what caused the stones to unexpectedly change color?

Subscribe To Our Space, Astronomy, Astrophysics, Earth and Xenology News!

Grab the latest RSS feeds right to your reader, desktop or mobile phone.

Subscribe to RSS headline updates from:
Powered by FeedBurner

Go to - MAIN PAGE

Copyright @ MessageToEagle.com All rights reserved.
Go to - MAIN PAGE


Advertise With Us!

Submissions

 Subscribe in a reader

Join Us On Facebook!

Other Popular Articles

Eyes on the Earth


Giant Viruses Are Ancient Living Organisms That Could Rewrite History Of Life On Earth

NASA's Satellites Examine Gigantic Force Of Nature We Cannot Control - Very Dangerous Super Typhoon Sanba

New Ambitious Mission Can Unlock Secrets Of Antarctica

Drones Will Over-Fly Hurricanes At Altitudes Greater Than 60,000 Feet - NASA's HS3 Mission Begins

Yellowstone Volcano: Scientists Try To Determine Risks For Future Eruptions


Lake In France Turns Red

This year, we have encountered the color red in places where we don't expect to see it. A while back the strange appearance of Azov Sea stunned residents who saw how the water had turned red. The red rocks in China have also puzzled scientists for a long time. Now, a lake in Southern France has also suddenly turned red.

Fighting Climate Change With Geoengineering - Controversial Idea Again In Focus! Will It Help Or Endanger Our Lives?
Environmental scientists have decided to reconsider once again a controversial idea of using futuristic ships to shoot salt water high into the sky over the oceans. Hopefully, the technique could reduce hurricane intensity and create...


Growing Stones An Incredible Geological Phenomena

Earth is an amazing planet and our nature is full of wonders. We have previously written about incredible singing plants. This time we would like to focus our readers' attention on another amazing geological phenomena, namely so-called growing stones. It is difficult to image that stones can really grow, but these stones seem to be alive!

CODITA: Measuring How Much Cosmic Dust Enters The Earth's Atmosphere

Do Gateways To The Underworld Open? Next Dangerous And Unexpected Opening In The Ground!

Giant Underwater Canyon Zhemchug Can Only Be Seen Entirely From Space


Yangtze River In China Turns Red

We have seen on a couple of occassions how lakes and seas have suddenly turned red. In August a lake in Southern France unexpectedly changed color and shortly before that the strange appearance of Azov Sea stunned residents who saw how the water had turned red....

Spectacular Fire-Devil Tornado Filmed Over Australia

Did A Huge Pacific Ocean Meteor Trigger The Catastrophic Ice Age?

W3Counter