Anthropocene is considered a unit for our current time. This period marks the footprint of human activities that significantly changed the world, especially toward—the ecosystems and geology of the planet. One factor that allows scientists to scale the range of Anthropocene is the impact of climate change.
Start of Anthropocene Epoch
In a new study, experts theorize that they had found the time when the Anthropocene began. The research was made possible through hints of biomarkers found at the depths of the Pacific Ocean.
These radioactive elements that the authors used were embedded in the marine sediments and corals of the largest ocean on the planet. Most specimens were collected from the northwest Pacific Ocean, just a few kilometers off Japan.
Most of the biomarkers the experts analyzed were a product of numerous atomic tests held across this region. The said scientific experiments were conducted in the 1950s when a transparent shift was detected in Earth's oceanic environments.
Through the clues gathered from the Pacific sediments, the authors concluded that the Anthropocene epoch started in 1954.
University of Tokyo's Atmosphere and Ocean Research Institute specialist Yusuke Yokohama, who also authored the study, explained in a press release that finding the clues about this new geological epoch involved the analysis of certain fallouts that transpired between the 1950s and 1963.
During these years, testing declined, and through the specimens found in the bay area, evidence of nuclear fission-related elements called plutonium was prominent, Yokohama continued.
Alongside the sediments, coral skeletons off the coast of Ishigaki Island, located in southwest Okinawa, also contained biomarkers of the fallout. When matched with the signatures collected from sediments, the experts got a clearer view of a new epoch.
Finding the Birth of the New Age
The study involved a heavy cross-referencing step in finding more clues from sediments outside the target area, as these materials are known to be easily washed away through natural factors such as oceanic currents, Science Alert reports.
Like trees, corals are composed of rings that show the distinction of ages they lived through as they developed. This part helps scientists to know more about the environmental features that are impossible to be collected by the state of water alone. The coral rings also complement the readings from the sediments.
One of the models the authors used was an accelerator mass spectrometry (AMS). This technology could provide details and identify each of the individual isotopes.
Yokohama explained that they had a hard time assessing the plutonium content across the region because, despite the few numbers of the element released to the ocean and the atmosphere, they were dispersed far, and it required their team to look for smaller signatures scattered in the area.
Previous studies suggest that the geological epoch started 11,700 years ago, right during the dawn of the Holocene. The Anthropocene, on the other hand, is still a topic for debate by the scientific community, as many factors accountable for the massive change, such as the first release of carbon emissions and the birth of industrialization, could be the distinct point it began.
The journal Scientific Reports published the study, "Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene."
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