Publikationsdatum:
2017-05-10
Beschreibung:
Ice sheets in the North American Arctic and, to a lesser extent, those in northern Eurasia calved large
quantities of icebergs that drifted through Fram Strait into the Greenland Sea several times during the late
Pleistocene. These icebergs deposited Fe oxide grains (45–250 mm) and coarse lithic clasts 〉250 mm matched to
specific circum-Arctic sources. Four massive Arctic iceberg export events are identified from the Laurentide and
the Innuitian ice sheets, between 14 and 34 ka (calendar years) in a sediment core from Fram Strait. These
relatively short duration (〈1–4 kyr) events contain 3–5 times the background levels of Fe oxide grains. They
began suddenly, as indicated by a steep rise in the number of grains matched to an ice sheet source, suggesting
rapid purges of ice through Fram Strait, due perhaps to collapse of ice sheets. The larger events from the
northwestern Laurentide ice sheet are preceded by events from the Innuitian ice sheet. Despite the chronological
uncertainties, the Arctic export events appear to occur prior to Heinrich events.
Materialart:
Article
,
PeerReviewed
Format:
text
DOI:
10.1029/2001PA000639
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