Icebergs and the Sea Floor of the East Greenland (Kangerlussuaq) Continental Margin

Abstract

The Kangerlussuaq margin is well furrowed by icebergs. The margin favors furrow preservation since sedimentation on the continental shelf is low, at least since the last (Flakkerhuk) glaciation and because shelf depths are well below wave base. While furrows are common in the Kangerlussuaq region, the icebergs that created the larger furrows are mostly absent. “Fresh” iceberg furrows are observed only on the bathymetric highs surrounding the 750-m-deep Kangerlussuaq Trough. Bathymetric barriers around the trough prevent icebergs with deep keels from entering the trough. Enormous and weathered (older) furrows are located inside the protected trough, apparently formed at paleocalving ice sheet termini, when the Greenland Ice Sheet extended onto the shelf. In the deeper sections of Kangerlussuaq Trough, Holocene mud is presently burying these older iceberg furrows. Paleocalving ice sheet margins, possibly from Iceland, account for muted furrows found on the upper continental slope of East Greenland. No sediment has been deposited over these hardground sites since 14,750 ± 720 BP.