When you think of the North Pole’s location, you probably imagine it is the centermost point at the top of our planet. However, the North Magnetic Pole has actually been moving gradually since away from the location it was first documented back in the 1830s.
Thanks, in part, to ESA’s Swarm satellite mission, scientists are now more confident in the theory that tussling magnetic blobs deep below Earth’s surface are at the root of this phenomenon.
|A new map shows
declination and dip pole locations around the northern hemisphere for.
(NOAA National Centers for Environmental Information / Cooperative
Institute for Research in Environmental Sciences)|
A new study published in the journal Nature Geoscience suggests that the changes in the North Pole’s location are explained by the movement of molten material in Earth’s interior. This, they say, has caused a titanic shift in the planet’s magnetic field. Essentially, the molten iron at the core of our planet helps to determine where Earth’s magnetic field downs down.
The Earth's north magnetic pole was first discovered by an explorer named James Clark Ross back in the 1830s. At that time, it was centered over the Nunavut territory in Canada. Since that time, scientists have kept track of its movement, which, until recently, was very slow.
But then in the 1990s, it began to pick up speed, moving from Canada toward Siberia in Russia. The movement of the pole has garnered interest in the media because it forces changes to navigational systems and smartphones that use its location as a focal point. In this new effort, the researchers have come up with what they believe is an explanation for the movement of the pole and why it began moving faster.
The researchers suggest that there are two large lobes of negative magnetic flux at the boundary of the core and the mantle. They further suggest that changes in molten metal flow in the core result in changes in the magnetic flux in the lobes.
The position of the pole is determined by the strength of the two lobes—when one gains strength, the other loses strength resulting in the pole moving in the stronger direction. The result is a constant tug-of-war between the two lobes. The current movement is therefore due to one of the lobes gaining the upper hand.
The researchers developed their theory after studying 20 years of satellite data (from the European Space Agency's Swarm) to measure the evolving shape of the Earth's magnetic field. Once they had developed their theory, they built a model that matched historical movement of the pole and used it to predict its future path.
It showed the pole continuing toward Russia at its current swift pace before slowing—with the pole eventually settling over a part of Siberia. The model was not able to provide any estimates for a more distant future.