Sun, 09 Jan 2011 13:43:56 +0000
Among the explanations proffered for the global animal die-offs of the past two weeks which began with the raining of some 3,000 dead black birds onto the small town of Beebe in Arkansas on New Year’s Eve is the Magnetic North Pole.
The Magnetic North Pole (MNP) should not be confused with the geographic North Pole. The Earth’s MNP is the point on the surface of the Northern Hemisphere at which the Earth’s magnetic field points vertically downwards (i.e., the “dip” is 90°). The MNP moves slowly over time due to magnetic changes in the Earth’s core.
Inbuilt navigation systems in birds and fish is believed to be affected by magnetism. Birds and fish rely on the Magnetic North Pole to travel to breeding grounds and warmed climes. But scientists said the MNP has been shifting toward Russia at an average of around 25 miles a year. There are fears that the shifting pole could be confusing the animals which means they do not migrate in time to avoid cold weather. Writing for Times Square Chronicle on Jan 7, Brett Lipton explains:
Over the past century The Magnetic North Pole has been shifting toward Russia at a steady pace, in fact, at an average of 25 miles per year, an alarming rate considering how many systems are dependent on its location. Compass needles in Africa, for instance, are drifting about 1 degree per decade. And globally the magnetic field has weakened 10% since the 19th century. Jan 7, 4:45 pm ET
But now we are told that the MNP is drifting at a rate almost twice as much than previously thought. From Wikipedia:
In 2001, it was determined by the Geological Survey of Canada to lie near Ellesmere Island in northern Canada at 81°18′N 110°48′W / 81.3°N 110.8°W / 81.3; -110.8 (Magnetic North Pole 2001). It was estimated to be at 82°42′N 114°24′W / 82.7°N 114.4°W / 82.7; -114.4 (Magnetic North Pole 2005 est) in 2005. In 2009, it was moving toward Russia at almost 40 miles per year.
Liz Goodwin reports for Yahoo on Jan 7, 2011, “Earth’s magnetic pole shifts, screws up runway at Florida airport“:
An airport in Tampa, Florida, has had to temporarily close its runways to keep up with Earth’s magnetic north pole, which is drifting toward Russia at a rate of 40 miles per year.
Fox News reports that the international airport was forced to adjust the signs on its busiest runway Thursday because pilots depend on the magnetic fields to navigate. The runway will be closed until Jan. 13, and will re-open with new taxiway signs that indicate its new location on aviation charts, the Tampa Bay Tribune reports.
Paul Takemoto, a spokesman for the FAA, says the Earth’s magnetic fields are constantly in flux — but rarely so much so that runway signage needs to be changed. “You want to be absolutely precise in your compass heading,” he told Fox. “To make sure the precision is there that we need, you have to make these changes.”
“The Earth’s poles are changing constantly, and when they change more than three degrees, that can affect runway numbering,” FAA spokesperson Kathleen Bergen told Fox News. It’s unclear whether any other airports will have to adjust their runways.
Earth’s magnetic field, which still flummoxes those who study it, “is thought to be generated deep inside the planet,” LiveScience writer Jeanna Bryner explains. “An inner core of solid iron is surrounded by an outer core of molten iron. They rotate at different rates, and the interaction between the regions creates what scientists call a ‘hydromagnetic dynamo.’ It’s something like an electric motor, and it generates a magnetic field akin to a giant bar magnet.”
Sometimes, the poles completely flip — and presumably when that happens, many bigger changes are afoot than modest tweaks to airport signs. The last time the planet experienced a polarity flip was 780,000 years ago.
For his part, Times Square Chronicle’s Brett Lipton concludes:
Another factor to consider is that the Earth’s Magnetic Poles Flip Regularly. In the past 330,000,000 years the poles have juxtaposed 400 times, or on an average of once every 825,000 years, the last such time was approximately 780,000+/- years ago, making us statistically within one standard deviation of an upcoming Magnetic Pole Reversal. Considering that these reversals take appromiately 1,000 years to complete and the massive move and reduction in strength, we may be within a handful of generations away for such a Magnetic North Pole Reversal.