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An ancient tree that contains a record of a reversal of Earth's magnetic field has been discovered in New Zealand. The tree -- an Agathis australis, better known as its M&Ccedilori name kauri -- was found in Ngawha, on New Zealand's North Island, during excavation work for the expansion of a geothermal power plant, stuff.nz reports. The tree, which had been buried in 26 feet of soil, measures eight feet in diameter and 65 feet in length. Carbon dating revealed it lived for 1,500 years, between 41,000 and 42,500 years ago... The lifespan of the kauri tree covers a point...

Nearly 42,000 years ago, when Earth’s magnetic fields reversed, this triggered major environmental changes, extinction events, and long-term changes in human behavior, a new study reports. The findings, made possible by a new radiocarbon record derived from New Zealand’s ancient kauri trees, raise important questions about the evolutionary impacts of geomagnetic reversals and excursions throughout the deeper geological record, the authors say. “Before this work,” says author Chris Turney in a related video, “we knew there were a lot of things happening around the world at 42,000 years ago, but we didn’t know precisely how… For the first time, we’ve...

Oxford University is involved in a research project to unearth 30,000 year old climate records, before they are lost forever. The rings of preserved kauri trees, hidden in New Zealand's peat bogs, hold the secret to climate fluctuations spanning back to the end of the last Ice Age... carbon dating and other analyses of the kauri tree rings. The trees store an immense amount of information about rapid and extreme climate change in the past. For instance, wide ring widths are associated with cool dry summer conditions... Tree rings are now known to be an excellent resource for extracting very...