Ebene News – GB – Ancient swamp kauri give clues to Earth’s atmospheric changes 42,000 years ago

The ancient rings of swamp kauri trees have shed light on crucial changes in Earth’s atmosphere, which may have led to the mass extinction of megafauna and the beginning of rock art

The Adams event is said to have caused frequent and dazzling light shows across the sky – similar to the Northern and Southern Lights
Photo: 123RF

Scientists from NIWA, the University of New South Wales Sydney (UNSW), the South Australian Museum and the University of Waikato collaborated on the study

They looked at what was happening just before the event known as the Laschamp Excursion – the last time the magnetic poles changed (north became south, south became north) This period lasted about 800 years, before the poles turned

He examined what this did on Earth and found that at the time the magnetic field was about 28% of the current strength

But new research has shown that the most tumultuous time was one of accumulation, as the poles migrated across the earth’s surface

Using radiocarbon data from kauri trees, the researchers assessed what happened to the geomagnetic field during pole migration

“We have known for a long time that the polarity of the Earth’s magnetic field has changed, about 41,000 years ago we can see it in our natural records,” said Andrew Lorrey, senior scientist of climate and environmental applications at NIWA

“The interesting thing here is that the strength of the magnetic field and the way it has decreased during this time is not something that has been very well defined in the past,” said Dr Lorrey

This sequence has been dubbed the Adams Event, after Douglas Adams, the sci-fi writer who wrote in The Hitchhikers Guide to the Galaxy that 42 was the answer to life, the universe, and to everything

Verified radiocarbon data from the trees showed at that time, the geomagnetic field would have been between zero and 6 percent of what it is today, he said


“We had virtually no magnetic fields – our shield of cosmic radiation was totally gone,” said Professor Chris Turney of UNSW Science

It would have caused frequent and dazzling light shows in the sky – similar to the Northern Lights and Southern Lights – happening all over the world Electric storms would have been more frequent as well

“The magnetic field protects us from a lot of what is happening with the sun, as well as from cosmic ray bombardment,” said Dr Lorrey

“What we found was that the magnetic field was drastically diminished before the full polarity switchover, and that’s when we think a climatic activity and reaction took place. produced on Earth about 42,000 years ago”

The study hypothesizes that such an event led to the arrival of cave art
Photo: Diego Camilo Carranza Jimenez / Agence Anadolu / AFP

Evidence from around the world shows that during this period there was a massive extinction of megafauna

“Unfiltered radiation from space tore particles of air in Earth’s atmosphere, separating electrons and emitting light – a process called ionization,” said Prof Turney

“Ionized air has ‘fried’ the ozone layer, causing a wave of climate change across the world”

The document hypothesized that such an event led to the arrival of cave art, as early humans sought shelter from extreme weather conditions

The discovery was only possible due to the unique circumstances offered to scientists by the ancient swamp kauri

The trunk of an ancient kauri tree in Ngāwhā, Northland
Photo: Supplied by NIWA / Nelson Parker

In the northern hemisphere, the bogs that preserved ancient trees were scraped by the last ice age

“Northland, on the other hand, during the last global ice maximum, was not glacial,” said Dr Lorrey “So our peats in many places have survived intact, and we have this wonderful treasure of sediment older peat bogs, which have been preserved with wood

“Nowhere else in the world do we have the volume and temporal coverage of wood, and in particular wood, that allow us to make very long tree rings

“At any clip we can extract swamp kauri trees, and it is quite common to find 600-1000 rings on these trees, so they are very useful for climate research and research. on carbon radio”

It enabled scientists to perform high-precision liquid scintillation to extract sequential blocks of wood composed of 40 annual rings, from four ancient kauri logs

Extreme heat and humidity are increasing around the world, threatening millions of lives and savings in places where it could become fatal to work outdoors, scientists say

A warmer world means the oceans are able to hold less dissolved oxygen, which is bad news for many fish

Countries will have to multiply their carbon reduction ambitions by five if the world is to avoid warming above 15C, says UN

According to the World Meteorological Organization, the increase in CO2 in 2018 was just above the average increase recorded over the last decade

Earth, Earth’s magnetic field, swamp kauri, geomagnetic inversion, magnetism

Ebene News – EN – The ancient swamp kauri has been giving clues about atmospheric changes on Earth for 42 000 years

Source: https://www.rnz.co.nz/news/national/436758/ancient-swamp-kauri-give-clues-on-atmospheric-changes-to-earth-from-42-000-years-ago