Kauri s excavated from the forest provide important scientific insights into climate change
ContactI found a very interesting article on climate change in relation to Kauri wood in the science magazine "Spektrum." I am publishing part of the article here on the Kauri blog. You can read the full article here.
The ancient Kauri trees provide interesting insights into the Earth's climate in the past, present, and future.
To this end, researchers examined this 38,000-year-old Kauri tree, which highlights the enormous scientific value of swamp kauri trees. Such a large, ancient specimen provides invaluable information through its growth rings to research groups specializing in their analysis.
This tree would help us to better understand an ancient global catastrophe and its consequences for the Earth's history.
As they grew, they stored information about the climate and the composition of the atmosphere in their annual rings. After they fell over, the trees sank deep into the peat bog, where they remained buried almost unchanged for thousands of years.
Tree rings shed light on the past in various ways. If you count them, you first find out how long a tree has lived. The width of the individual annual rings in turn allows conclusions to be drawn about changing growth conditions. A chemical analysis of each ring provides information on precipitation patterns, relative humidity and soil moisture.
Using computer programs and a visual examination of tree ring patterns, samples from different times and places can be combined into long sequences, so-called chronologies. In some cases, these extend seamlessly over thousands of years and reveal supra-regional patterns in climate events. For comparison: historical climate records only go back 150 years.
This extended timeline now provides climate modelers with important data for predicting future climate trends, such as those related to human-induced global warming. Researchers have compiled a series of additional Kauri chronologies that extend even further back in time. Each of these covers several millennia of the past 60,000 years.
Ancient samples of * Kauri* are invaluable to scientists around the world. For example, researchers can use them to determine the age of other plant, human, and animal remains that have survived for tens of thousands of years.
Using the radiocarbon dating method, the age of the " Kauri " tree was determined to be 38,000 years.
A new finding is that the sea level rose by more than 15 meters 15,000 years ago due to melting ice sheets. And this happened much faster than previously assumed, as the new curves show: The process was over after just 160 years. This shows that Sea levels can also rise very suddenly, not just gradually as a result of rising global temperatures - a potentially important lesson in times of melting Antarctic ice sheets.
Apart from that, the Kauri annual rings provide information about changes in the Earth’s magnetic field, such as those that occurred in 1859. At that time, there was a solar flare—a massive coronal mass ejection—that bombarded the Earth with radiation. This resulted in a one-day geomagnetic storm known as the Carrington Event.
Solar storms are not the only geomagnetic events preserved in the wood of the “ Kauri .” About 42,000 years ago, the Earth’s magnetic field began to drift for a millennium and briefly reversed during a polar excursion. When scientists calibrated the tree’s radiocarbon data using the calibration curve, it became clear that the data spanned the beginning of this event. Kauri had grown into a sapling about 42,715 years ago and fell into the mud 1,600 years later.
The information contained in the tree's rings was cross-referenced with other natural archives to establish an accurate sequence of events. According to this analysis, when the " Kauri " tree was a few hundred years old, the Earth's magnetic field weakened dramatically. At the same time, the Sun entered a periodic, centuries-long period of inactivity characterized by far fewer sunspots and lower energy output—a phenomenon known as a "grand solar minimum."
During this phase, the solar wind and the solar magnetic field weakened, serving as a protective shield for the Earth against cosmic radiation. As a result, the Earth's atmosphere was poorly protected for several hundred years.
In the following few centuries, the ice sheets in North America grew rapidly, while the climate in Australia became drier and the lakes in the interior disappeared. Incidentally, these changes took place more than 10,000 years after the arrival of modern humans on the continent.
According to the study, humans are not responsible for the disappearance of animal and plant species at that time. This explains a series of patterns around 42,000 years ago that were previously a mystery.
Severe geomagnetic and solar events could—contrary to previous understanding—very well influence the global climate, the scientists continue. This perspective opens up a new multidisciplinary field of research. The planet and the climate system now appear to be much more variable. The key to all these new insights and perspectives came from excavated Kauri trees. “Coming across a period with such a weak Earth’s magnetic field is truly unusual,” say the scientists who studied the tree, “and then finding such a long-lived tree that survived precisely that period.”
#kauri tree #kauri #kauri wood #climate change #swamp kauri #
Michael Beaupoil
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