Comparison between Greenland ice-margin and ice-core oxygen-18 records

Niels Reeh, Hans Oerter, Henrik Højmark Thomsen

Publikation: Bidrag til tidsskriftArtikelForskningpeer review

39 Citationer (Scopus)

Abstrakt

Old ice for palacoenvironmental studies retrieved by deep core drilling in the central regions of the large ice sheets can also be retreived from the ice-sheet margins. The δ 18O content of the surface ice was studied at 15 different Greenland ice-margin locations. At some locations, two or more records were obtained along closely spaced parallel sampling profiles, showing good reproducibility of the records. We present ice-margin δ 18O records reaching back to the Pleistocene. Many of the characteristics δ 18O variations known from Greenland deep ice cores can be recognized, allowing an approximate time-scale to be established along the ice-margin records. A flowline model is used to determine the location on the ice sheet where the margin ice was originally deposited as snow. The Pleistocene-Holocene δ 18O change at the deposition sites is determined by comparing the δ 18O values in the ice-margin record to the present δ 18O values of the surface snow at the deposition sites. On the northern slope of the Greenland ice sheet, the Pleistocene-Holocene δ 18O change is about 10‰ in contrast to a change of 6-7‰ at locations near the central ice divide. This is in accordance with deep ice-core results. We conclude that δ 18O records measured on ice from the Greenland ice-sheet margin provide useful information about past climate and dynamics of the ice sheet, and thus are important (and cheap) supplements to deep ice-core records.

OriginalsprogEngelsk
Sider (fra-til)136-144
Antal sider9
TidsskriftAnnals of Glaciology
Vol/bind35
DOI
StatusUdgivet - 2002

Programområde

  • Programområde 5: Natur og klima

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