Berlin 2014 – wissenschaftliches Programm
MS 9.7: Vortrag
Donnerstag, 20. März 2014, 15:45–16:00, DO24 1.205
Deep-Sea Astronomy with Accelerator Mass Spectrometry — •Jenny Feige1, Anton Wallner2, L. Keith Fifield2, Gunther Korschinek3, Silke Merchel4, Georg Rugel4, Peter Steier1, Steve Tims2, Stephan R. Winkler1, and Robin Golser1 — 1University of Vienna, Austria — 2ANU Canberra, Australia — 3TUM, Germany — 4HZDR, Germany
Accelerator Mass Spectrometry (AMS) is a highly sensitive method to measure extremely low isotopic ratios of long-lived radionuclides relative to its stable isotope.
Inspired by findings of an excess of 60Fe in a ferromanganese crust approximately 2 Myr ago, which was interpreted to be of supernova-origin, we use this method to determine concentrations of a variety of radionuclides in deep-sea sediment samples covering a time range from 1.7 to 3.2 Myr.
An international collaboration of different AMS facilities is utilized to search for signatures of 26Al, 53Mn, and 60Fe above terrestrial background production and extraterrestrial influx. In addition, the cosmogenic radionuclide 10Be is measured to confirm existing magnetostratigraphic dating of the samples and for comparison with atmospheric production ratios of 26Al/10Be. All 10Be and 26Al measurements are finished, 53Mn and 60Fe is in progress. Measurement results and the influence of different background sources on a potential supernova signature will be presented and discussed.