ELECTRICAL MEASUREMENTS ON THE GREENLAND ICE-SHEET PROJECT-2 CORE

The Greenland Ice Sheet Project 2 (GISP2) electrical conductivity meas urement (ECM) record is an indication of the concentration of H+ in th e core. The ECM detected seasonal variations in the nitrate concentrat ion of the core which were used to assist in dating the core by annual layer counting. Volcanic eruptions that produce acidic aerosols are r ecorded in the ECM record. Evidence of biomass burning is detected by the ECM because fire-related ammonium emissions neutralize the acids i n the core. Rapid climate transitions associated with the Younger Drya s and Dansgaard/Oeschger interstadial events alter the concentration o f alkaline dust and are detected by the ECM. The ECM has been used to develop stratigraphic ties between the GISP2 and the Greenland Ice Cor e Project cores. Users of the data should be aware of some instrument- related artifacts in the ECM record.