The magnetic poles of the Earth are constantly moving, hence they currently do not exactly coincide with the North Pole and the South Pole. They move so much that reaches a point where they are invested every certain period of time. This, interesting as it is, has catastrophic consequences.
Weeks ago I made a trip of hundreds of kilometers just to see a tree: Tane Mahuta. It is the oldest tree in New Zealand, a kauri tree over 2,500 years old. It is what makes these trees special, their age. Native to the North Island of New Zealand, these trees are special for their spiritual significance to the island’s indigenous community, but also for the contribution they can provide to the scientific community due to their age. Due to their great longevity, they are living history that allow us to analyze the Earth’s past. And that’s exactly what a new study published in Science has done.
Earth, 42,000 years ago
A group of researchers has analyzed the fossilized trunks of various kauri trees found in New Zealand. Remains of trees that lived on Earth about 42,000 years ago, precisely when the last reversal of the magnetic poles is believed to have occurred. The rings on these logs reflect the consequences of the investment.
By reading the rings of the fossilized logs, researchers have been able to deduce how the environment was affected by the magnetic pole shift. According to the study, there were around 800 years of climatic disasters in the area. These climatic disasters include glacial expansion, high-level cosmic radiation, electrical storms, and changes in the behavior of the biosphere, as well as the extinction of part of it.
When cosmic radiation occurs in carbon molecules in the atmosphere, carbon-14 occurs naturally. Carbon-14 is captured very easily by trees, so it is possible to analyze the amounts that exist according to the year and the rings of a tree trunk. Researchers found extremely high amounts for around eight centuries 42,000 years ago, they believe the direct cause was the reversal of the magnetic poles.
The magnetic poles of the Earth, in addition to serving us for compasses (and the problems they give), also act as a protective shield for cosmic radiation. The Earth’s magnetic field, however, weakens when there is a reversal of the poles and until they stabilize again. According to the study, some 200 years before the reversal of the magnetic poles, the intensity of the magnetic field had already dropped to 0.6% of its current strength. We were left without a shield for several centuries.
Results of running out of a protective shield against cosmic radiation? Loss of the ozone layer, large-scale climate change, glaciation, ultraviolet radiation, extinctions of animal species and flora … Coincidentally, New Zealand’s first cave paintings date back to about 42,000 years ago, so it is believed that the hominids of that time began to take refuge in caves at that time.
Via | CNN
More information | Science