Speaker
Description
The detection of cosmic signatures in deep-sea, ice, and lunar samples has made an important contribution to nuclear astrophysics in recent years. In particular, ${}^{60}$Fe from near-Earth supernovae has been imprinted during the time periods $2-3$ and $7-8\,\mathrm{Myr}$ ago.
This data corroborates theoretical studies that suggest that more than $10$ SNe exploded at a distance of $50-150\,\mathrm{pc}$ over the last $10-15\,\mathrm{Myr}$. Their overriding shock fronts created a volume of hot gas that is seen in observational data and referred to as the 'Local Bubble', which currently engulfs our Solar System.
We here explore for the first time sedimentary records on land, in particular from the oldest and driest desert on Earth; the Atacama Desert, Chile. In contrast to previous archives, Atacama Desert deposits are easily accessible, reach more than $10\,\mathrm{Myr}$ into the past and are not affected by continuous aqueous diffusion.
The low sedimentation rates in the Atacama Desert that are similar to deep-sea sediments, as well as the hyper-arid conditions facilitate the preservation of cosmic traces over millions of years, bearing the potential for the detection of individual supernovae within each of the broad signals.
