Terrestrial climate signal of the 8200 yr BP cold event in the Labrador Sea region

Accelerated melting of Greenland ice has raised concern about the future impact of enhanced freshwater discharge on regional climate through its effect on ocean circulation. An abrupt cooling event ca. 8200 cal. yr B. P. has been linked to meltwater from the decaying North American ice sheet. Oxygen isotopic analyses of cellulose from subfossil Sphagnum mosses, isolated from a Newfoundland peat core, reveal a pronounced anomaly ca. 8350 yr B. P. with a duration of similar to 150 years. The maximum estimated delta O-18(precipitation) change, 4.53% +/- 1.05% (Vienna Standard Mean Ocean Water), is the largest observed in the circum-North Atlantic region. The magnitude of change exceeds that predicted by recent paleoclimate simulations. Comparisons with recent records of surface and deep ocean proxies in the Labrador Sea and the wider North Atlantic region suggest synchroneity. However, an similar to 200 year delay between the responses of the Labrador Sea region and the Greenland Ice Sheet to the effects of meltwater release remains to be explained.