Penny Ice Cap Cores, Baffin Island, Canada, and the Wisconsinan Foxe Dome Connection: Two States of Hudson Bay Ice Cover

Science, Vol. 279, p. 692-695, 1998 

D.A. Fisher, R.M. Koerner, J.C. Bourgeois
Terrain Sciences Division, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada.
G. Zielinski, C. Wake
Glacier Research Group, Morse Hall, University of New Hampshire, Durham, NH 03824-3525, USA.
C.U. Hammer, H.B. Clausen, N. Gundestrup, S. Johnsen
Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen.
K. Goto-Azuma
Nagaoka Institute of Snow and Ice Studies, 187-16 Suyoshi-machi, Nagaoka-shi, Niigata-ken 940, Japan.
T. Hondoh
Institute of Low Temperature Science, Hokkaido University, Sapporo 060, Japan.
E. Blake, M. Gerasimoff
Icefield Instruments, 3 Glacier Drive, Unit 2, Whitehorse, Yukon Y1A 5H4, Canada.

ABSTRACT.
Ice cores from Penny Ice Cap, Baffin Island, Canada, provide continuous Holocene records of oxygen isotopic composition (d¹⁸O, proxy for temperature) and atmospheric impurities. A time scale was established with the use of altered seasonal variations, some volcanic horizons, and the age for the end of the Wisconsin ice age determined from the GRIP and GISP2 ice cores. There is pre-Holocene ice near the bed. The change in d¹⁸O since the last glacial maximum (LGM) is at least 12.5 per mil, compared with an expected value of 7 per mil, suggesting that LGM ice originated at the much higher elevations of the then existing Foxe Dome and Foxe Ridge of the Laurentide Ice Sheet. The LGM d¹⁸O values suggest thick ice frozen to the bed of Hudson Bay.