Magnetic North on the move [credit: ESA]

Few will notice anything, but some airport runways will have to change their markings.

The team of researchers that maintain the World Magnetic Model (WMM) has updated it and released it a year ahead of schedule due to the speed with which the pole is moving, reports Phys.org.

The newly updated model shows the magnetic north pole moving away from Canada and toward Siberia.

The magnetic north pole is the point on the Earth that compasses designate as true north. It is the result of geological processes deep within the planet—molten iron flow creates a magnetic field with poles near the geographic North and South Poles.

But unlike the geographic poles, the magnetic poles can move—and the magnetic north pole has been moving faster in recent years, which made necessary the early update of the WMM.

The WMM is a model maintained jointly by the U.S. National Oceanic and Atmospheric Administration and the British Geological Survey—its purpose is to show what Earth’s magnetic field looks like, most particularly, where the locations of the magnetic poles lie. Data for the model comes from satellites and 160 land-based observatories.

The model is normally updated every five years; thus, the next update is scheduled for 2025. THE WMM is important because of the critical role it plays in navigation—in addition to GPS, militaries around the world rely on it for a wide variety of navigational applications.

It is currently not known why the poles drift. Some have suggested it is due to an underground jet stream of sorts. Nor is the mechanism driving them understood.

Full article here.

via Tallbloke’s Talkshop

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December 18, 2019 at 07:57AM