Ancient trees discovered in New Zealand hold a 42,000-year-old record of Earth’s magnetic field reversal.
The most recent pole reversal, called the Laschamp excursion, occurred about 41,000 to 42,000 years ago. During this time, the North Magnetic Pole moved to the Southern Hemisphere and then back to the North.
The scientists studied ancient kauri trees found in wetlands in northern New Zealand. These trees were alive during the Laschamp excursion. By analyzing growth rings, the researchers measured spikes in atmospheric radiocarbon levels, which occur when Earth’s magnetic field weakens. This helped them create a detailed timeline of the changes.
Previous research focused on what happened when the magnetic poles flipped, when Earth’s magnetic field was only 28% stronger than it is today. However, this new research suggests that the biggest changes occurred during a transition period called the Adams Event. During this time, the magnetic field dropped to just 0-6% of its current strength.
The researchers compared their findings with data from other Pacific locations and used climate models to show how the Adams Event caused major environmental changes. These changes included the growth of ice sheets in North America and shifts in wind patterns and tropical storm systems.
Professor Anthony Dosseto from the University of Wollongong explains that the Adams Event caused dramatic changes in the planet’s climate. In Australia, for example, the climate became much drier. This event may explain the extinction of megafauna in Australia and the disappearance of Neanderthals in Europe.
It may also explain the sudden increase in cave art during this time. As cosmic radiation increased, people may have sought shelter in caves, leading to a surge in cave art.
The study warns that if a similar shift in the magnetic field were to occur today, the impact would be catastrophic. Cosmic radiation could destroy power grids and satellite systems as well as trigger rapid climate change.
The most recent pole reversal, called the Laschamp excursion, occurred about 41,000 to 42,000 years ago. During this time, the North Magnetic Pole moved to the Southern Hemisphere and then back to the North.
The scientists studied ancient kauri trees found in wetlands in northern New Zealand. These trees were alive during the Laschamp excursion. By analyzing growth rings, the researchers measured spikes in atmospheric radiocarbon levels, which occur when Earth’s magnetic field weakens. This helped them create a detailed timeline of the changes.
Previous research focused on what happened when the magnetic poles flipped, when Earth’s magnetic field was only 28% stronger than it is today. However, this new research suggests that the biggest changes occurred during a transition period called the Adams Event. During this time, the magnetic field dropped to just 0-6% of its current strength.
The researchers compared their findings with data from other Pacific locations and used climate models to show how the Adams Event caused major environmental changes. These changes included the growth of ice sheets in North America and shifts in wind patterns and tropical storm systems.
Professor Anthony Dosseto from the University of Wollongong explains that the Adams Event caused dramatic changes in the planet’s climate. In Australia, for example, the climate became much drier. This event may explain the extinction of megafauna in Australia and the disappearance of Neanderthals in Europe.
It may also explain the sudden increase in cave art during this time. As cosmic radiation increased, people may have sought shelter in caves, leading to a surge in cave art.
The study warns that if a similar shift in the magnetic field were to occur today, the impact would be catastrophic. Cosmic radiation could destroy power grids and satellite systems as well as trigger rapid climate change.
Kategori
🗞
BeritaTranskrip
00:00Terima kasih.