Key to Earth's core found in Arctic Circle

Tarduno

n the high Canadian Arctic, researchers at the University have unraveled some of the mystery surrounding the Earth's magnetic field and have revealed evidence that suggests the Earth's poles may undergo a reversal in the future.

The research, led by John Tarduno, professor of geophysics, strongly suggests that several of the characteristics of the magnetic field long thought to operate independently, such as the field's polarity and strength, may be linked. If so, then the strength of the field, which has been waning for several thousand years, may herald a pole reversal--a time where compasses all over the Earth will point south instead of north. The findings were published in the October 16 issue of Proceedings of the National Academy of Sciences.

To collect evidence, Tarduno led 14 students on four excursions, the most recent in the summer of 2000, far above the Arctic Circle, just 11 degrees south of the North Pole, near the edge of the "tangent cylinder"--a giant, theoretical cylinder that represents an area of possible high turbulence in the molten iron of the core.

Where this edge contacts the Earth's crust high above the Arctic Circle should lie traces of the twisted magnetic field in the crystals.

It's there that Tarduno and his students drilled out several sections of the 95-million-year-old rock, labeled it, and packed it up to be shipped back to the University.

Using a device that can detect extremely minute amounts of magnetism in small samples, Tarduno analyzed the samples to determine the direction and intensity of the magnetic signature sealed in the rock's crystals.

The results showed a correlation between the stability of the poles and the intensity of the field, meaning there's likely a single mechanism in the Earth governing the magnetic field. The findings also suggest that in as little as a few centuries the Earth's magnetic poles may flip, sending compasses angling toward the South Pole.

Tarduno plans to extend these studies into the very ancient Earth in the hopes of discovering how the Earth's magnetic field first began.

The research was funded by the National Science Foundation and the Canadian Polar Shelf Project.

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