We are facing an anomaly over South Atlantic, researchers are calling it South Atlantic Anomaly. It is a region of the Earth’s magnetic field that has shifted so much that satellites get disrupted when they fly through it.
The researchers provided information acquired from southern Africa in a research paper, which was published in February, that might help us figure out what the heck is going on in the South Atlantic Anomaly, which stretches from Chile to Zimbabwe. It is weakening, though there might be various causes for this.
The Earth's magnetic field, in reality, switches polarity very frequently – on average, every several million years. A million years is a long period, but in the big scheme of the Earth's billions of years of geological history, these magnetic field reversals are very common. As the researchers note in their paper, that process may be repeating — however the actual composition of the Earth's mantle beneath the field may also play a role.
The Earth's magnetic field provides our first line of protection against the solar wind, which is full of charged particles that may damage the ozone layer, which protects us from space ultraviolet radiation. The fact that satellites are being disturbed by the massive radiation emitted by the South Atlantic Anomaly demonstrates how dangerous magnetic pole reversal is. For one thing, it would undoubtedly have an impact on more than simply compass needles.
Researchers looked at spreading seafloors produced when lava cooled to acquire a better understanding of what's going on in the South Atlantic Anomaly and whether comparable phenomena had occurred previously. They reasoned that crystals in the magma would inform them in which direction the Earth's magnetic field was polarised. These polarised seabed minerals developed parallel strips of reversed crystals over thousands and millions of years, providing us with a record of prior reversals.
The activities of Iron Age inhabitants residing in the northern region of modern-day South Africa resulted in a similar phenomenon. They'd burn their grain bins and mud dwellings regularly in a ceremony supposed to relieve drought conditions, and in doing so, they produced the circumstances for their clay to cool in the same manner the seabed did, with the minerals in the clay pointing in the direction of the magnetic pole.
Researchers pieced together the history of the South Atlantic Anomaly from around 425 to 1550 C.E. by investigating archaeological remains from multiple locations and discovered comparable abnormalities in three separate time periods: 400 to 450 C.E., 700 to 750 C.E., and 1225 to 1550 C.E.
They believe that the current oscillations are most likely not a coincidental or random event, but rather part of a historical trend of magnetic field changes in this region. This region's susceptibility to oscillations is likewise not coincidental. A region known as the African Large Low Shear Velocity Province sits 1,800 miles under southern Africa, a heavy region that may be pressing down on the boiling liquid iron at the Earth's core, which is responsible for producing the magnetic field in the first place.
Historical variations and unique iron flow cannot fully explain the general trend in the Earth's diminishing magnetic field, which geologists ascribe to forces beneath the Earth's mantle, but they can help us put what we're witnessing into context.
And it is in this setting that the 160-year pattern of a diminishing magnetic field, which might signal the big flip, appears to be occurring alongside these smaller, less frequent oscillations. While time will tell how bad everything is, it's evident that there's not much we can do to prevent the big switch from happening.