Studying the rings inside trees can teach us a lot. By studying these patterns, a field known as dendrochronology—the study of tree rings—can reveal details about a tree’s age, history of fire, and history of insect outbreaks. The rings of a tree can also provide important information on the climate circumstances that the tree has experienced and, consequently, the evolution of the earth’s climate . Recently, researchers discovered an old tree that existed when the Earth’s magnetic field was nearly entirely reversed.
Ngāwhā kauri
Although the ancient tree is an Agathis australis, its Māori name, kauri, is more widely used. It was discovered buried 26 feet below the surface in Ngawha on the north island of New Zealand. With dimensions of eight feet in diameter and sixty-five feet in length, the tree seems to have existed between forty-one thousand and forty-two thousand years ago .Alan Hogg of the University of Waikato in New Zealand remarked, “There is nothing like this anywhere in the world.” “There is nothing like this Ngāwhā kauri.”
What is the magnetic field of Earth?
Heat is continuously transferred from the Earth’s solid inner core to its liquid iron outer core. Convection, or movement, of that iron results from this. Iron creates a magnetic field since it is a metal and conducts electricity .
The magnetic field generated by a typical bar magnet is quite similar to this one. Because there are two poles on either end of the magnet, it is known as a dipole. The strongest magnet is found at these endpoints. The magnetic field can be thought of as arching lines that enter the south pole and exit the north pole.
Although it is not constant throughout time, the Earth’s magnetic field is in line with its axis of rotation. Scientists are still unsure of the reason behind the periodic disintegration and subsequent re-establishment of the magnetic field throughout geological history. When this occurs, it may either revert to its initial configuration or orient itself in the opposite direction, reversing the north and south poles .
Throughout Earth’s history, this pole reversal has occurred on occasion, sometimes for a few thousand years and other times for more than thirty million years .
Why Is There a Magnetic Field on Earth?
The Earth’s magnetic field is quite significant. We are shielded from solar radiation, especially from the sun, by the force it produces. Large amounts of radioactive particles are released into space by the sun, and our magnetic field diverts these particles away from Earth, protecting humans from radiation exposure .
When the magnetic field weakens, what happens?
The earth’s magnetic field weakened to the point where it almost collapsed 565 million years ago. Over the course of around 75,000 years, it was roughly 10 times weaker than it is now [7].”Earth would not have been shielded from the solar wind, which can erode the atmosphere and eventually rob the planet of water, if the geodynamo had completely collapsed.” John Tarduno from the University of Rochester clarified .
The Excursion of Laschamp
The Laschamp Event, which occurred approximately 41,000 years ago, is the last time the earth’s poles almost fully reversed. To completely comprehend what transpired during that time, scientists will find it very beneficial to examine Kuari’s rings .
According to Chris Turney, the lead scientist examining the tree, “these priceless analyses will allow us to investigate the magnitude and rate of change when the magnetic field reversed during the Laschamp; something not possible before and of great interest given recent changes in the Earth’s magnetic field.” This is because the Earth’s magnetic field has a major impact on how much radiocarbon carbon is formed in the upper atmosphere. What current occurrences is he talking about? To put it briefly, the poles are moving quickly.
The Magnetic Field of the Earth is Changing
Because the earth’s poles are dynamic, scientists have been tracking the north pole’s movement since 1831, when it was first noted to be six miles per year on average. However, this speed has risen to 25 miles per year in recent decades .
The magnetic field is represented by scientists using the World Magnetic Model (WMM). Along with numerous other civilian systems, it is utilized by the US Department of Defense and the UK Ministry of Defense. In essence, knowing the location of the poles is crucial .
The northern magnetic pole is currently shifting toward Siberia and away from the Canadian Arctic. To stay up with this movement, the WMM is typically modified every five years. It was last revised in 2014 and was supposed to remain in effect until 2020, however in 2018 it was discovered to be erroneous in the Arctic, necessitating another change
This sudden erratic behavior has some scientists concerned that another pole flip could be on the horizon. Peter Olsen, a geophysicist at John Hopkins University, disagrees.
“It’s the comparison between a global depression and a stock market correction,” he stated. “How do you know the stock market today is not heading toward a worldwide depression, a crash? Well, it could be. However, the likelihood that it is a correction and will recover is much higher.
Regardless matter what is coming, with the help of Ngāwhā kauri, scientists will be better able to grasp what has happened in our geological history in order to prepare for our prospective future.
