Beryllium 10 concentrations in the Greenland Ice Sheet Project 2 ice core from 3–40 ka

Abstract

A nearly continuous record of 10 Be (half‐life of 1.5×10 6 years) concentrations is reported in the Greenland Ice Sheet Project 2 (GISP2) ice core for the time period between 3288 and 40,055 years B.P. The resolution is between 20 and 50 years in the Holocene. During the Pleistocene, sampling was coarser, with the resolution ranging between 50 and 200 years. Both concentrations and fluxes are reported. Concentrations of 10 Be are observed to correlate strongly with δ 18 O and more weakly with snow accumulation rates. Beryllium 10 fluxes show less dependence than do concentrations on climate‐related parameters. A good correlation exists between Δ 14 C and 10 Be for centennial scale variations, which are most likely due to heliomagnetic modulation of the 10 Be production rate in the atmosphere. There is no evidence of a long‐term geomagnetic effect on the 10 Be flux at GISP2. The interpretation of the record depends strongly on the model one uses to infer atmospheric 10 Be concentrations from the measured concentrations in snow.