Wednesday, March 9, 2011

North Magnetic Spurt?

We really are confronted with two questions.  The first is that it appears that the North Magnetic Pole (NMP) is now clipping along at forty miles per year.  Sustained this means it is travelling at four thousand miles per century and able to swap poles in a millennia.  This is much faster than indicated in the geological record.  Does such movement happen in spurts?

The second question is whether we are able to discern such spurts in the geological record by careful measurement?  It seems we should be able to do so with deep sea cores.

At least we now have a clear indication of how fast the process actually is, and it is certainly within the correct parameters.

Once again we get the doubtful theory about the iron core causing all this.  See my posting on the topic by googling this blog under Earth’s Magnetic Field.  Even without my alternative explanation, the iron core idea is rubbish.

Magnetic north shifting by 40 miles a year, might signal pole reversal

The magnetic pole is moving faster than at any time in human history, causing major problems for navigation and migratory wildlife.

By Bryan NelsonMon, Mar 07 2011

POLE POSITION: Magnetic north is moving so fast that it is hampering navigation. (Photo:Calsidyrose/Flickr)

The magnetic north pole is currently shifting at a faster rate than at any time in human history — almost 40 miles a year — and some experts believe that it may be the beginning of a complete pole reversal, according to the Independent.

The changes are already beginning to cause major problems for aviation, navigation and migratory animals which use the Earth's magnetic field to orient themselves. Some airports have even had to change the names of their runways to better correspond to their current direction relative to magnetic north.

Ever since the magnetic north pole was first discovered in 1831, geologists have been tracking its progress. Unlike true north (which is marked by the Earth's axis), magnetic north is constantly on the move due to changes in the planet's molten core, which contains iron. Throughout most of recorded history, the pole has been positioned at or around Canada's icy Ellesmere Island, but if it keeps moving at its current rate, it won't be long before it sits above Russia instead. 

The thing that really makes the pole's current movement so unusual, however, is the speed that it is shifting. In the last decade alone, movement has increased by a third, throwing off compasses by roughly one degree every five years.

Changes that fast have already caused major headaches for the U.S. Federal Aviation Administration. Tampa International Airport in Florida has just spent a month renaming all of its runways, which are named after the degree at which they point on a compass. Similar changes were recently made to runways at Fort Lauderdale and Palm Beach, and across the country runways now need to be renamed at least once every five years.

The shifting pole may also become a grave concern for migratory wildlife, such asbirds, turtles and other sea creatures which use Earth's magnetic field to navigate over great distances. It's unclear how capable these animals are of recalibrating their navigational instincts to compensate for the changes.

The rapid shifting of the pole's position has even prompted some experts to speculate that the Earth's entire magnetic field may be preparing to "flip," whereby all compasses completely invert and point south instead of north. It may sound radical, but in geological time, pole reversals are actually quite common. Though they typically occur once every 400,000 years or so, it's been 780,000 years since the last flip.

Scientists disagree about how a pole reversal would effect ecosystems around the world, but some alarmists warn of a planet-altering catastrophe, whereby earthquakes and monumental tsunamis threaten the Earth for decades. Though such radical doomsday prophecies cannot be completely ruled out, the vast majority of scientists are tempered by calmer predictions.

"Reversals typically take about 10,000 years to happen," said Jeffrey Love of the U.S. Geological Survey. "And 10,000 years ago civilisation did not exist. These processes are slow, and therefore we don't have anything to worry about."

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