CONTINUOUS MEASUREMENTS OF HYDROGEN-PEROXIDE, FORMALDEHYDE, CALCIUM AND AMMONIUM CONCENTRATIONS ALONG THE NEW GRIP ICE CORE FROM SUMMIT, CENTRAL GREENLAND

A new deep core drilling operation started in 1990 in central Greenlan d and in 1992 reached the bottom at a depth of 3028 m.b. surface. Taki ng advantage of recent developments in the analytical technique of che mical trace species, continuous high resolution measurements of H2O2, HCHO, NH4+ and Ca2+ concentrations were performed directly on the ice core in the field. During the 1991 season all four components were mea sured simultaneously between 1300 m.b. surface and 2300 m.b. surface, corresponding to the time interval between 8000 and 38,000 years B.P. In this paper an overview of the results and our first interpretations in terms of climatic changes are given.