Electrical conductivity measurements from the GISP2 and GRIP Greenland ice cores

• Published in: Nature
• Main Authors: Dahl-Jensen, Dorthe, Clausen, Henrik Brink, Taylor, K. C., Hammer, C. U., Alley, R. B., Gow, A. J., Gundestrup, N. S., Kipfstuh, J., Moore, J. C., Waddington, E. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1993
• Subjects: Greenland; Greenland ice core; Greenland Ice core Project; Greenland ice cores; Greenland Ice Sheet Project; GRIP; ice core; Ice Sheet
• Online Access: https://curis.ku.dk/portal/da/publications/electrical-conductivity-measurements-from-the-gisp2-and-grip-greenland-ice-cores(5f6a47f0-ed45-11dd-bf70-000ea68e967b).html; https://doi.org/10.1038/366549a0

THE direct-current electrical conductivity of glacial ice depends on its acidity 1-3 , and can also indicate changes in climate, as ice formed in cold, dusty periods has a high concentration of alkaline dust 1,4,5 , which significantly reduces the conductivity 6,7 compared to warmer, less dusty periods. Here we present electrical conductivity records for the Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice-core Project (GRIP) ice cores, drilled 28 km apart to enable direct comparison of the results. The upper parts of both records are consistent with previous evidence from other Greenland cores 4,8& #150;12 for a stable Greenland climate during the Holocene, and a series of warm events punctuating the last glacial period. However, there is a significant discrepancy between the two records in the bottom 10% of the cores, calling into question recent reports of climate variability in the last interglacial 4,8 and the penultimate glaciation 8 . At this stage, it is too early to say what exactly is causing the discrepancy, although ice flow may have introduced some discontinuities into the records. Further work will be necessary to establish how much climatic information it will eventually be possible to extract from the lower parts of the two cores. Udgivelsesdato: 09 december