Tracing Land to Ocean River Transport with Cosmogenic Isotopes
Beryllium stored in marine sediments can help scientists study erosion and other environmental changes.
By Sarah Witman 23 August 2017
Beryllium has a stable isotope (Be-9) and a rare cosmogenic variety (Be-10), their difference being merely one neutron. Because the radioactive Be-10 decays within the half-life of 1.4 million years, it does not exist on Earth unless produced by cosmic rays. Rainfall brings Be-10 down to Earth’s surface from the atmosphere, where it binds to soil particles or becomes dissolved in seawater and mixes with stable beryllium. Key to the method is that particles in soil and river sediment now provide a cosmogenic to stable beryllium ratio characteristic of regional erosion, whereas in seawater, the ratio provides a measure of the terrigenous input into an entire ocean basin.
https://eos.org/research-spotlights/tracing-land-to-ocean-river-transport-with-cosmogenic-isotopes
