Earth's magnetic north pole is hurtling toward Russia
By Tara John, CNN
Updated 7:32 AM ET, Tue February 5, 2019
(CNN)The north magnetic pole has been drifting so fast that it could be a problem for smartphone maps and navigation systems.
The pole has been the friend of navigators for millennia, beckoning compass needles from virtually every point on the planet. And unlike the geographic north pole, which is fixed, the north magnetic pole has been slowly migrating over time -- moving across the Canadian Arctic toward Russia since 1831.
But its swift pace toward Siberia in recent years at a rate of around 34 miles per year has forced scientists to update the World Magnetic Model -- used by civilian navigation systems, the North Atlantic Treaty Organization, and US and British militaries -- a year ahead of schedule.
"Due to unplanned variations in the Arctic region, scientists have released a new model to more accurately represent the change of the magnetic field between 2015 and now," the US National Oceanic and Atmospheric Administration's National Centers for Environmental Information wrote in a press release Monday.
The model, which is commissioned by the British and US military agencies, is typically updated every five years, the most recent being in 2015. But the agency explained that the "out-of-cycle update ... will ensure safe navigation for military applications, commercial airlines, search and rescue operations, and others operating around the North Pole."
And while the model's primary user is the military, it has found its way into Google and Apple's civilian mapping systems. The difference will be minor for civilian purposes, however, and the changes are largely limited to latitudes above 55 degrees. "For most users below 55 degrees north, there is no real difference," Ciaran Beggan, a geophysicist at the British Geological Survey, which creates the map with the NOAA, told CNN.
Scientists first noticed the change in 2018 thanks to a "huge amount of satellite data," which showed the pole had gone beyond the model's predicted area, Beggan said.
The drift is caused by processes deep inside the planet, he said. Earth's magnetic field is created in its liquid outer core, which is made of liquid iron and nickel. "As it flows it creates an electronic current and that current makes a magnetic field -- which drifts with the hot runny core," he said.
There have been a few theories about why the pole's movement has increased in recent years -- from around 6 miles a year between 1900 and 1980 before accelerating to around 24 to 31 miles a year in the past two decades. Some scientists think a jet stream of molten liquid is pushing the north pole, while others have suggested that the south and north magnetic poles are reversing positions.
There is nothing to worry about, Beggan said. "It is unusual behavior in historical terms, (by) geological scales it is not unusual," he said. "The magnetic field (changes) continuously, but it is partly because of its natural behavior," he added.
No comments:
Post a Comment