Open AccessThe Greenland Ice Sheet Project 2 depth‐age scale: Methods and results
Author(s) -
Meese D. A.,
Gow A. J.,
Alley R. B.,
Zielinski G. A.,
Grootes P. M.,
Ram M.,
Taylor K. C.,
Mayewski P. A.,
Bolzan J. F.
Publication year - 1997
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97jc00269
Subject(s) - ice core , geology , greenland ice sheet , groenlandia , ice sheet , volcano , physical geography , stratigraphy , climatology , geomorphology , paleontology , geography , tectonics
The Greenland Ice Sheet Project 2 (GISP2) depth‐age scale is presented based on a multiparameter continuous count approach, to a depth of 2800 m, using a systematic combination of parameters that have never been used to this extent before. The ice at 2800 m is dated at 110,000 years B.P. with an estimated error ranging from 1 to 10% in the top 2500 m of the core and averaging 20% between 2500 and 2800 m. Parameters used to date the core include visual stratigraphy, oxygen isotopic ratios of the ice, electrical conductivity measurements, laser‐light scattering from dust, volcanic signals, and major ion chemistry. GISP2 ages for major climatic events agree with independent ages based on varve chronologies, calibrated radiocarbon dates, and other techniques within the combined uncertainties. Good agreement also is obtained with Greenland Ice Core Project ice core dates and with the SPECMAP marine timescale after correlation through the δ 18 O of O 2 . Although the core is deformed below 2800 m and the continuity of the record is unclear, we attempted to date this section of the core on the basis of the laser‐light scattering of dust in the ice.