Isotopic imprint of the Solar system encounter with interstellar gas cloud around 660 BC (2610 BP)

Abstract

Abstract We analyse the long lived radionuclide data (14C, 10Be and 36Cl) in tree rings and Greenland ice cores referred to the 660 BC event. The hypotheses of solar superflare impact on the atmosphere and Solar system collision with small sized dense interstellar cloud are considered. Decisive role in clarifying the situation is the experimental data on other isotope content available in ice for the periods under discussion. The data on 10Be and 36Cl (GRIP and NGRIP stations in Greenland) during the 660 BC event favour the second hypothesis. Various assumptions on the relationship between isotope production and deposition rates in the atmosphere are considered.