Accumulation Histories of GISP2 Ice During the Last Glacial Period: Record Based on In-Situ Produced 14 C

Investigator: Devendra Lal dlal@UCSD.edu  (Principal Investigator current)

Abstract

This research award  seeks to obtain comprehensive information on the accumulation history of the GISP2 ice core, using a nuclear method based on in-situ 14C produced by cosmic rays in the firn "oxygen" during accumulation. This method was developed in a study of the well-documented Holocene of the GISP2 core, whose chronology and accumulation rates are fairly well constrained. This method allows characterization of ice accumulation rates in situations where reliable flow models cannot be constructed. The proponents seek to complete 14C analyses of several deep ice samples of ages 16-39 ky BP in hand, and also of ice samples which accumulated during special solar activity epochs. The first set of data would yield information on accumulation rates during the glacial period, while the second would shed light on the effects of changes in climate and cosmic ray fluxes during different solar activity levels.