Earth’s magnetic north on a Russian voyage

By | January 6, 2010

Earths magnetic north on a Russian voyage

Earth’s north magnetic pole is racing toward Russia at almost 65 kilometres a year because of magnetic changes in the planet’s core, new research says.

The core is too deep for scientists to directly detect its magnetic field. But researchers can infer the field’s movements by tracking how Earth’s magnetic field has been changing at the surface and in space.

Now, newly analyzed data suggest that there’s a region of rapidly changing magnetism on the core’s surface, possibly being created by a mysterious “plume” of magnetism arising from deeper in the core.

And it’s this region that could be pulling the magnetic pole away from its long-time location in northern Canada, said Arnaud Chulliat, a geophysicist at the Institut de Physique du Globe de Paris in France.

Magnetic north, which is the place where compass needles actually point, is near but not exactly in the same place as the geographic North Pole. Right now, magnetic north is off the shore of Ellesmere Island.

Navigators have used magnetic north for centuries to orient themselves when they’re far from recognizable landmarks.

And although global positioning systems have largely replaced such traditional techniques, many people still find compasses useful for getting around underwater and underground.

The magnetic north pole had moved little from the time scientists first located it in 1831. Then, in 1904, the pole began shifting northeastward at a steady pace of about 15 kilometres a year.

In 1989, it sped up again, and, in 2007, scientists confirmed the pole is moving toward Siberia at 55 to 60 kilometres a year.

A rapidly shifting magnetic pole means magnetic-field maps need to be updated more often to allow compass users to make the crucial adjustment from magnetic north to true North.

Future positions of the pole are estimates. No one knows when another change in the core might pop up elsewhere, sending magnetic north wandering in a new direction.

via Earth’s magnetic north on a Russian voyage – thestar.com.

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