GEOSCAN Search Results: Fastlink


TitleThe Mt Logan Holocene-late Wisconsinan isotope record: tropical Pacific-Yukon connections
AuthorFisher, D; Osterberg, E; Dyke, A; Dahl-Jensen, D; Demuth, M; Zdanowicz, C; Bourgeois, J; Koerner, R M; Mayewski, P; Wake, C; Kreutz, K; Steig, E; Zheng, JORCID logo; Yalcin, K; Goto-Azuma, K; Luckman, B; Rupper, S
SourceThe Holocene vol. 18, no. 5, 2008 p. 667-677,
Alt SeriesEarth Sciences Sector, Contribution Series 20080375
PublisherSAGE Publications
Mediapaper; on-line; digital
File formatpdf (Adobe® Reader®)
NTS114O; 115B; 115C; 115F; 115G
AreaPacific northwest; Mount Logan; Prospector-Russell Col; Canada
Lat/Long WENS-142.0000 -138.0000 62.0000 59.0000
Subjectsenvironmental geology; hydrogeology; geochemistry; surficial geology/geomorphology; Holocene; Wisconsinian glacial stage; glaciers; atmospheric geochemistry; hydrologic environment; ice samples; core studies; stable isotope studies; oxygen isotopes; source areas; hydrogen isotopes; climate, arctic; climatology; paleoclimatology; precipitation; peat bog geochemistry; paleotemperatures; temperature; volcanism; Younger Dryas; La Niña; El Niño; Phanerozoic; Cenozoic; Quaternary
Illustrationstables; sketch maps; plots; time series; bar graphs; profiles
ProgramEnhancing resilience in a changing climate
Released2008 08 01
AbstractThe ice core recovered from Prospector Russell Col on Mt Logan (5.4 km a.s.l.), in the Yukon spans over 20 000 years. This unique record offers a Pacific view of the stable isotope and chemical record from the Lateglacial to the present. The timescale is based on seasonal counted years, the largest known volcanic acid signatures and the major shift in stable isotopes and chemistry at the end of the Younger Dryas. There are large and sustained changes in the stable isotopic record that are anti-correlated with marine and continental chemistry series. The oxygen-18 in this area is not a proxy for palaeotemperature but rather for source region. The last major isotope shift in AD 1840 in d(18O) and chemistry is compared with the Quinn's ENSO record. During periods of more frequent La Niña (stronger tropical easterlies) there is more zonal flow of water vapour transport to the Pacific Northwest, d(18O) values are larger and the deuterium excess d smaller. These periods coincide with periods of lower accumulation/precipitation in southern Yukon. The Holocene d(18O) record indicates many large shifts between the meridional (strong El Niño) and zonal (La Niña). Comparison of the Logan isotopic record and the moisture/temperature-sensitive time series of peat bog inception dates for the Northwest shows a strong correlation (0.36) that points to high accumulation rates coincident with low d(18O) and enhanced meridional flow. Major changes in the core at 4200 BP and 7000-8000 BP point to enhanced meridional flow, which coincide with big changes in the Pacific palaeorecords of the balance between El Niño and La Niña. 4200 BP seems to have inaugurated the `modern' ENSO world.

Date modified: