Magnetic North's erratic behavior forces update to global navigation system

Jan. 14 (UPI) — Magnetic North is shifting rapidly, throwing off the World Magnetic Model that powers a variety of global navigational systems.

Scientists were originally scheduled to release an updated model this week — a fix for the accumulating anomalies — but due to the government shutdown, the update’s release has been delayed until the end of the month.

Scientists with the British Geological Survey and the U.S. National Oceanic and Atmospheric Administration update the World Magnetic Model every five years. The last full update came in 2015. Shortly afterwards, a portion of Earth’s magnetic field briefly shifted deep beneath northern South America.

Over the last few years, the erratic behavior continued.

“Since late 2014 the core field has varied in an unpredicted, and currently unpredictable, manner,” British Geological Survey scientist Will Brown wrote in a blog update. “This led to the WMM becoming less accurate, particularly at high northern latitudes.”

Most recently, Magnetic North migrated rapidly into Siberia. According to a recent report by Nature, scientists realized the model was in serious trouble early last year.

“Researchers from NOAA and the British Geological Survey in Edinburgh had been doing their annual check of how well the model was capturing all the variations in Earth’s magnetic field,” Alexandra Witze reported. “They realized that it was so inaccurate that it was about to exceed the acceptable limit for navigational errors.”

In December, NOAA issued a partial update to patch up the most glaring errors, but the model remains inaccurate. The forthcoming update is desperately needed.

Scientists think the magnetic field’s erratic behavior is explained by changes in the flow of iron inside Earth’s outer core. But it’s also possible Earth’s magnetic poles are on the verge of reversing.

The planet’s magnetic poles flip every 200,000 to 300,000 years, but an attempted flip 40,000 years ago failed. Earth’s poles haven’t flipped in nearly 800,000 years. In other words, they’re due.

Though powered by the swirl of iron and nickel in Earth’s molten core, a variety of factors can influence the planet’s magnetic field.

“The magnetic poles drift, the field strengthens and weakens, and the immense magnetic field of the sun, carried by the solar wind, constantly batters at it from the outside,” according to Brown. “The effect of all these changes vary depending on when and where you are on, under, or above the Earth’s surface.”

Researchers with NOAA and BGS hope to gain a better understanding of what’s driving the magnetic field’s erratic behavior before their next World Magnetic Model update, scheduled to be completed by the end of the year.

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Science News – UPI.com

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