• Boundary scavenging in the Pacific Ocean: a comparison of 10 Be and 231 Pa
    with R. F. Anderson, W. S. Broecker, S. E. Trumbore, H. J. Hofmann, and W. Wolfli
    Concentrations of U, Th, 231Pa and 10Be were measured in Holocene sediments from two cores collected off the west coast of South America, two cores from the East Pacific Rise, two from the equatorial Pacific and one from the south Pacific central gyre. Our results, together with data from 5 cores reported in the literature, show that boundary scavenging plays a major role in the removal of 10Be from the Pacific Ocean. Deposition rates of 10Be at three margin sites are more than an order of magni…Read more
  •  1
    Increased production of cosmogenic 10Be during the last glacial maximum
    with R. F. Anderson, W. S. Broecker, S. E. Trumbore, H. J. Hofmann, and W. Wolfli
    BERYLLIUM-10 is produced by spallation of nitrogen and oxygen atoms by cosmic rays in the upper atmosphere. Its production rate is proportional to the flux of cosmic rays, which is modulated by solar activity and the strength of the Earth's magnetic field1,2. Weakening of the magnetic field allows more cosmic rays to impinge on the Earth's atmosphere, thereby increasing 10Be production. Here we report that the ocean-wide average accumulation rate of 10Be in Pacific sediments, which reflects the …Read more