Back in May 2020, the European Space Agency revealed in its study that Earth’s magnetic field is weakening in some areas over Africa and South America. The scientists at ESA rightly termed this process in the change of geomagnetic field or the surface magnetic field as 'South Atlantic Anomaly'.
Now, in a new study conducted by a team of researchers at the University of Alberta, the mystery behind the Earth’s magnetic field over the Pacific has been solved. The study, titled ‘Weak magnetic field changes over the Pacific due to high conductance in lowermost mantle’ was published in the Nature Geoscience this week.
In the press release, the University of Alberta professor and lead author of the study, Mathieu Dumberry explained that the weakening might be due to the weaker core flow under the Pacific.
Dumberry also mentioned that the topic has been a subject of curiosity since the 1930s when the fact about the weakening of the magnetic field was first established. “Our study highlights that the core-mantle boundary region is quite heterogeneous. The conductance of the lowermost mantle is most probably not uniform around the globe. In fact, it seems to be higher in the Pacific as compared to any other area.”
He added that the large ‘magnetic friction’ might be the reason behind weak local core flow. This, in turn, results in a few changes in the Earth’s magnetic field in the Pacific.