Earth's magnetic poles have been on a hasty move in the last two decades. Recently, the geoscientists at Leeds University claimed that they are close to pinpoint the reason behind the accelerated motion.
According to the geodynamo theory, the magnetic field of our planet is the outcome of the thermally and electrically conductive currents, which traverse between the bottom of Earth's mantle and its outer core in a rotatory manner.
Due to the ever-changing nature of the high-temperature molten flows, it is not surprising that the strength of Earth's magnetic field and its positioning change from time to time. For a few times in the geological history, the two magnetic poles (also called the di-poles) completely flipped their position. But what's puzzling is that the pace of their movement has picked up significant speed in the recent years.
For example, since its first measurement in 1831, the magnetic north has been slowly moving out of the Canadian arctic towards Russia's Siberia region. The movement accelerated after 1990, increasing its previous speed of 0 to 15 km (about 9 miles) per year to between 50 and 60 km (31-37 miles) per year.
The scientists noted that the "tug of war" between two gigantic lobes of magnetic flux, which are located on the core–mantle boundary (CMB) under Canada and Siberia, had been the main deciding factor for the location of the magnetic north pole. (The CMB is where Earth's silicate mantle meets with its liquid iron-nickel outer core, about 2891 km (1796 mi) underneath our feet.) By analyzing satellite data collected from the past two decades, the Leeds team determined that recent fluctuations in the flow of Earth's outer core (between 1970 and 1999) caused the Canadian lobe to stretch, which in term reduces its "grip" on the pole location and results in the pole's hasty drift.
They also predicted that the current trajectory and pattern of movement would remain for the next ten years, pushing the magnetic north up to 660 km (410 miles) closer towards Siberia.
This latest research is reported in the journal Nature Geoscience.
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