(ORDO NEWS) — The protective shell of our planet is no longer the same as before. Over the past two centuries, its magnetic power has dropped dramatically, and no one has the slightest idea of the reasons for this.
At the same time, an interesting soft spot in the field called the South Atlantic Anomaly emerged over the Atlantic Ocean, which has already proven problematic for fragile satellite orbital designs.
Both of these disturbing observations fuel concerns that we may be seeing signs of an impending reconfiguration that will cause the compass points to turn in different directions, the so-called reversal of the magnetic poles.
But researchers pursuing a new study that models the planet’s magnetic field in the recent past warn that we shouldn’t be too hasty in assuming this will happen.
“Based on the similarity to the reconstructed anomalies, we predict that the South Atlantic Anomaly is likely to disappear within the next 300 years and that the Earth is not moving towards a polarity reversal,” says geologist Andreas Nilsson of Lund University in Sweden.
At least not in the near future. So for now, we can breathe easy.”
However, if our geologic history is anything to go by, it’s likely that the planetary magnetic field lines will eventually point in the opposite direction.
What such a reversal would mean for humanity remains to be seen. The last time such a grand event happened was just 42,000 years ago, when life on Earth seemed to be going through a rough patch as a rain of high-speed charged particles swept through our atmosphere.
Whether people noticed this – perhaps in response to this they began to spend more time in shelters – one can only guess.
However, given today’s reliance on electronic technology, which can be vulnerable without the protection of a magnetic umbrella, even the most rapid field changes will leave us defenseless for the foreseeable future.
Therefore, geologists are striving to find out which fluctuations, staggers and wanderings of the field portend a catastrophe, and which are commonplace.
Much of what we know about the history of the magnetic field comes from how its orientation causes particles in molten materials to line up before they lock into place when they solidify. By digging through the layers of mineralized needles, you can get pretty clear indications of which way the compass has been pointing for millennia.
Likewise, pottery artifacts from archaeological sites may also provide insight into the direction of a field in later times by imprinting its direction in clay before firing.
In a new study, scientists from Lund University and Oregon State University have analyzed samples of volcanic rocks, sediments and artifacts from around the world to reconstruct a detailed timeline of how our planet’s magnetic shell has changed since the last ice age.
“We have mapped changes in the Earth’s magnetic field over the past 9,000 years, and anomalies like the one seen in the South Atlantic are likely to be recurring phenomena associated with corresponding changes in the strength of the Earth’s magnetic field,” says Nilsson.
Given a millennial perspective, it quickly becomes clear that a soft spot in the South Atlantic is not unusual. Around 1600 B.C. there was a similar geological change that lasted for about 1300 years and then leveled off again.
Assuming the same underlying mechanisms are at work, it is likely that the current easing will soon recover and disappear without ending with a global reconfiguration. It is even likely that the magnetic field as a whole will return to a strength that we have not seen since the early 19th century.
However, this is not proof that a reversal is about to occur – just the new data shows that we should not interpret the current anomalies of diminishing strength as strong indications of a polar reversal.
In a way, this is good news. But this leaves us in the dark about exactly what such a massive geological process would look like on the scale of a human lifetime.
Having records as detailed as this one will help us get a clearer picture, and perhaps if the worst happens, we’ll be ready for it.
Contact us: [email protected]