A new study says that rapid changes in the movement of the liquid outer core are weakening the Earth magnetic field in some areas of the planet’s surface.
“Most surprising is that rapid changes occur almost sudden, in the magnetic field of the Earth,” says study co-author Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen.
The findings suggest that simultaneously are also rapid changes occurring in the liquid metal 3,000 kilometers below the surface, he says.
The swirling flow of molten iron and nickel around the solid core of the Earth triggers an electrical current that generates the magnetic field of the planet.
The study, recently published in Nature Geoscience, simulated the Earth’s magnetic field using nine years of accurate satellite data.
Researchers have found that fluctuations in the magnetic field have occurred in several widely separated areas of the Earth.
In 2003 scientists found marked changes in the magnetic field in the region of Asia and the Pacific. In 2004, however, the changes are focused on South Africa.
These changes “may indicate the possibility of an upcoming reversal of the geomagnetic field,” says study co-author Mioara Mandea a scientist at the German Research Centre for Geosciences in Potsdam.
The Earth’s magnetic field has reversed hundreds of times over the past billion years and the entire process could take thousands of years.
The decline of the magnetic field is also opening the Earth’s upper atmosphere to intense charged particle radiation, scientists say.
Satellite data show that the geomagnetic field is reduced in the South Atlantic, as Mandea, which adds an oval-shaped area east of Brazil is significantly weaker than similar latitudes elsewhere in the globe.
“It is in this area where the display effect of the magnetic field is severely reduced, allowing high energy particles radiation belt to penetrate the higher altitudes below a hundred kilometers of the atmosphere,” says Mandea.
This radiation does not influence temperatures on Earth. However, the particles do affect technical and radio equipment, and electronic equipment can damage satellites and aircraft, says Olsen, the Danish Space Center.
The observation continues
The study documents the rate at which changes the flow of the Earth’s core, said Peter Olson, a professor of geophysics at Johns Hopkins University in Baltimore (USA), who was not involved in the research.
Using satellite imagery, researchers have a nearly continuous measurement of changes he says.
“They provide a good basis for further monitoring,” says Olson