Article
 

Chronology reconstruction for the disturbed bottom section of the GISP2 and the GRIP ice cores: Implications for Termination II in Greenland

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/8g84mr653

Descriptions

Attribute NameValues
Creator
Abstract
  • We have reconstructed chronology for the disturbed bottom parts of the GRIP and GISP2 ice cores using the combined paleoatmospheric records of CH₄ concentration and δ¹⁸O[subscript atm] in the trapped gases. Our reconstructed ages for basal ice samples are based on comparison of published measurements of CH₄ and δ¹⁸O[subscript atm] from the disturbed section of the GRIP and GISP2 cores with the same properties in the Vostok ice core. NGRIP δ¹⁸O[subscript ice] values are also used to constrain the chronology during the end of marine isotope stage 5e. For each sample, we assign an age that represents the unique or most probable time of gas trapping, given its gas composition. Of 157 samples with CH₄ and δ¹⁸O[subscript atm] data, 10 give unique ages. Twenty-five newly measured values of the triple isotope composition of O₂ from the disturbed section of the GISP2 core add a third time-dependent gas property that agrees with our reconstruction. Our reconstruction supports earlier conclusions of Landais et al. (2003) that the disturbed section primarily includes ice from the last interglacial (MIS 5e) and the penultimate glacial period (MIS 6). The oldest ice in the basal layer of GISP2 and GRIP has an age ≥237 ka. The climate history we derive suggests that the last interglacial at Summit, Greenland, around 127 ka was slightly warmer than the current interglacial period. Reduction of various ion concentrations in ice and thickening of the ice sheet during Termination II was similar to that in Termination I.
  • Keywords: chronology, Termination II, ice core
Resource Type
DOI
Date Available
Date Issued
Citation
  • Suwa, M., J. C. von Fischer, M. L. Bender, A. Landais, and E. J. Brook (2006), Chronology reconstruction for the disturbed bottom section of the GISP2 and the GRIP ice cores: Implications for Termination II in Greenland, Journal of Geophysical Research, 111, D02101, doi:10.1029/2005JD006032.
Journal Title
Journal Volume
  • 111
Journal Issue/Number
  • D2
Academic Affiliation
Rights Statement
Funding Statement (additional comments about funding)
  • This work was supported by a gift from the Gary Comer Foundation and the Office of Polar Programs, NSF.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details BrookEdwardCEOASChronologyReconstructionDisturbed.pdf 2017-12-06 Public Download