The effects of flowline length evolution on chemistry - δ18O profiles from Penny Ice Cap, Baffin Island, Canada

• The isotopic and chemical signatures for ice-age and Holocene ice from Summit, Greenland, and Penny Ice Cap, Baffin Island, Canada, are compared. The usual pattern of low δ 18 0, high Ca 2+ and high Cl - is presented in the Summit records, but Penny Ice Cap has lower than present Cl- in its ice-age ice. A simple extension of the Hansson model (Hansson, 1994) is developed and used to simulate these signatures. The low ice­ age Cl - from Penny Ice Cap is explained by having the ice-age ice originating many thou­sands of km inland near the centre of the Laurentide ice sheet and much further from the marine sources. Summit's flowlines all start close to the present site. The Penny Ice Cap early-Holocene δ180's had to be corrected to offset the Laurentide meltwater distortion.The analysis suggests that presently the Summit and Penny Ice Cap marine impurity ori­ ginates about 500 km away, and that presently Penny Ice Cap receives a significant amountoflocal continental impurity.

Ämnesord

Natural Sciences  (hsv)

Earth and Related Environmental Sciences  (hsv)

Other Earth and Related Environmental Sciences  (hsv)

Naturvetenskap  (hsv)

Geovetenskap och miljövetenskap  (hsv)

Annan geovetenskap och miljövetenskap  (hsv)

Earth Science with specialization in Physical Geography  (uu)

Geovetenskap med inriktning mot naturgeografi  (uu)

Nyckelord

Ice cores

aerosols

Arctic

Canada

Laurentide Ice Sheet

Penny Ice Cap