Pacific: Radioactive particles mark a new era

The discovery of radioactive material in marine sediments and corals in the Pacificoff the coast of Japan seem to be the beginning of a new Age. This is theanthropocene, which the scientists discovered with specific biomarkers. The material examined comes from nuclear tests conducted in the region in 1950. It marks a clear change in the ocean. The research team speculates that the Anthropocene began in 1954.

The complexity of these samples lies in the sediments. Yes, because they can be spread over a large area or moved by ocean currents. The samples provide a good date for scientists on sediment material. Among the analytical techniques used are the mass spectrometry with accelerator. It makes it possible to identify the individual isotopes in the sediments.

Our job was to find clear indications of declines from 1950 to 1963, when testing largely ceased. We’ve taken root samples from the bay and there are clear signs of plutonium from relapse. However, we also collected coral skeletons from Ishigaki Island, southwest of Okinawa, that contained precipitation. By comparing sediments to corals, we can more accurately date the signatures we see in sediments. It was difficult to analyze the plutonium in our samples, as three tons of plutonium were released into the sea and atmosphere during the period in question, but those three tons spread far and wide. So we’re actually looking for incredibly small signatures.

Yusuke Yokoyama, a geoscientist at the University of Tokyo

For now, however, no one can be sure of the exact beginning of the Anthropocene. However, this study is important for determining the definition of the Anthropocene, as well as for improving ocean and climate models. also theexploration from previous tsunamis and other natural disasters.