Is Magnetic Pole Shift a Cause for Alarm?

A recent Wall Street Journal article cited the movement of the earth’s magnetic field as a cause for potential alarm ~ but still posed the question, “Should we be alarmed?”

The earth's magnetic field is weakening at an accelerating rate. It is 15% weaker than it was at the time the north magnetic pole was "discovered"—and claimed for King William IV—by a British explorer in 1831. Should we be worried?

What's more, the north magnetic pole, after meandering through Canadian islands for half a millennium, is heading off across the Arctic Ocean toward Russia at the breakneck speed of 37 miles a year. It will pass close to the geographical North Pole in a few years. With the dastardly Russians about to pinch this British heirloom, should we be doubly worried?

While the WSJ admits we don’t know the answer, it contends there is no concrete evidence pointing to reasons for undue concern:

Though odds are strongly against it, it is just possible that this is the beginning of a polar reversal, when the North and South magnetic poles swap places. This used to happen quite often—by which I mean every hundred thousand years or so—but it's now 780,000 years since it last occurred, an unusually long interval.

During such a reversal there is probably a very brief interval (oops, there I go again; by "very brief" I mean a thousand years or so) when the earth has no stable magnetic field. This does not seem to have bothered our ancestors: There is no evidence of biological extinctions peaking during magnetic-pole reversals.

Click here for the complete article.

NASA Finds Huge Breach in Magnetic Field

Artist’s concept of a THEMIS probe exploring the space around Earth.

NASA this week reported that spacecraft have discovered a breach in Earth's magnetic field 10 times larger than anything previously thought to exist. Solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms.

But the breach itself is not the biggest surprise, NASA says. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.

"At first I didn't believe it," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."

Solar-Wind Protection Lessened

The magnetosphere is a bubble of magnetism that surrounds Earth and protects us from solar wind. Exploring the bubble is a key goal of the THEMIS mission, launched in February 2007. The big discovery came on June 3, 2007, when the five probes serendipitously flew through the breach just as it was opening.

"The opening was huge—four times wider than Earth itself," says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data.

The event began with little warning when a gentle gust of solar wind delivered a bundle of magnetic fields from the Sun to Earth. Like an octopus wrapping its tentacles around a big clam, solar magnetic fields draped themselves around the magnetosphere and cracked it open. The cracking was accomplished by means of a process called "magnetic reconnection."

Breach Unexpectedly Large

High above Earth's poles, solar and terrestrial magnetic fields linked up to form conduits for solar wind. Conduits over the Arctic and Antarctic quickly expanded. Within minutes they overlapped over Earth's equator to create the biggest magnetic breach ever recorded by Earth-orbiting spacecraft.

The size of the breach took researchers by surprise. "We've seen things like this before, but never on such a large scale," says physicist Jimmy Raeder, "The entire day-side of the magnetosphere was open to the solar wind."

Implications Are ‘Seismic’

The circumstances were even more surprising. Space physicists have long believed that holes in Earth's magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north.

"To the lay person, this may sound like a quibble, but to a space physicist, it is almost seismic," says Sibeck. "When I tell my colleagues, most react with skepticism, as if I'm trying to convince them that the sun rises in the west."

Click here for the complete NASA press release.