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The 103 meter Mt. Logan, Canada ice core was drilled with an electromechanical drill in 1980 from a site on a saddle
at 60 deg. 35 min. N, 140 deg. 35 min. W at an elevation of 5340 meters a.s.l.
Further pit sampling in 1981, 1986, 1988, and 2000 have stretched the core record to 2000.
Data has been collected on the stable isotopes of oxygen and allowed for an assesment of the
accumulation rate at the site. Annual increments have been determined by a number of methods.
Total B-activity variations, delta 18-O oscillations, nitrate concentration variations,
and in a few selected sections sodium ion concentration variations were used to count annual layers.
Below 50 meters, delta 18-O oscillations become obscured and the other annual indicators replaced the
use of isotope ratios. For more details on the delta 18-O time series and net acumulation time series
see the following references.
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Moore, G.W.K., G. Holdsworth, and K. Alverson, 2002,
Climate change in the North Pacific region over the past three centuries
Nature, 420, 6914, 401-403 (28 November 2002); doi:10.1038/nature01229
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Holdsworth, G., H.R. Krouse and M. Nosal, 1992, Ice core climate signals from Mount Logan, Yukon A.D. 1700-1897, In: Climate Since A.D. 1500. Raymond S. Bradley and Philip D. Jones (eds.). Routledge. London and New York. pp. 483-504.
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Monaghan, M.C. and G. Holdsworth, 1990, The origin of non-sea-salt sulphate in the Mount Logan ice core, Nature 343:245-248.
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Holdsworth, G., H.R. Krouse, and E. Peake, 1988, Trace-acid ion content of shallow snow and ice cores from mountain sites in western Canada, Annals of Glaciology 10:57-62.
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Mount Logan isotope and accumulation data
