Human activities have radically changed the climate from a certain geological period called Anthropocene. Of the japanese researchers were recently able to estimate the beginning of this era thanks to biomarkers individuals discovered inside marine sediments and corals. Leftover materials from atomic tests dating from the fifties, these biomarkers found off the coast of Japan, in the North Pacific, are radioactive.
In fact, despite the atomic bombings of Hiroshima and Nagasaki in 1945, Japan never ceased to actively conduct nuclear tests who have strongly polluted the environment ocean at that time. This is how the Tokyo University scientists were then able to assert that the Anthropocene started in 1954.
In particular, they based their studies on the basis of data collected from several sediments collected in the region.
Heavy plutonium pollution following nuclear tests in Japan
The 1950s to 1963 were marked by a advanced major in nuclear research in Japan. Indeed, the day after the capitulation, the scientists of the time did not stop praise the merits of nuclear energy in the media. Even if the development of nuclear power to create an energy revolution in Japan, it has heavily polluted the Earth’s ecosystems.
Japanese researchers then endeavored to find evidence the persistence of radioactive fallout having polluted the marine ecosystem during this period. Yusuke Yokoyamaone of the geoscientists who worked on this project, claimed that they have detected traces of plutonium trapped inside sediments or corals.
Chemical analysis by mass spectrometry and crossing of sediments
The researchers have analyzed carrots sediment using a technique called accelerator mass spectrometry. However, they had great difficulty in identify radioactive traces dating from this period. Indeed, ocean currents and other climatic factors have already scattered the debris sailors affected by this nuclear pollution.
They then had the idea of compare the sediments collected on site with those found throughout the Pacific. The dating of coral skeletons collected on the island of Ishigaki southwest of Okinawa served as the basis to identify sediment necessary to conduct this study. These data will allow scientists to better understand climate change and anticipate geological hazards like tsunamis.