Ancient Ngawha Kauri Witness to Great Change
About 42,000 years ago, Earth was beset with oddness. Its magnetic field collapsed. Ice sheets surged across North America, Australasia and the Andes. Wind belts shifted across the Pacific and Southern Oceans. Prolonged drought hit Australia; that continent’s biggest mammals went extinct. Humans took to caves to make ochre-colour art. Neanderthals died off for good, Alanna Mitchell writes for The New York Times.
Through it all, Mitchell reports, one giant kauri tree stood tall. Until, after nearly two millenniums, it died and fell in a swamp, where the chemical records embedded in its flesh were immaculately preserved. That tree, unearthed a few years ago near Ngawha Springs in northern New Zealand, finally allowed researchers to fit a tight timeline to what before had seemed like an intriguing but only vaguely correlated series of events.
What if, the researchers posited, the crash of the magnetic field spawned the climatic changes of that era? And to think that the Ngawha kauri had borne witness to the whole thing.
“It must have seemed like the end of days,” said Chris Turney, a geoscientist at the University of New South Wales, and part of a large team that described the findings in a study published in Science. “And this tree lived through all that. Which is incredible, really.”
Original article by Alanna Mitchell, The New York Times, February 18, 2021.
Photo by Nelson Parker.