The origin and flux of icebergs released into the Last Glacial Maximum Northern Hemisphere oceans: the impact of ice‐sheet topography

Abstract The precipitation fields of a palaeoatmospheric general circulation model are used to derive estimates of the geographical distribution, and flux, of icebergs from the Laurentide, Fennoscandinavian and eastern Siberian ice‐sheets at the Last Glacial Maximum (LGM). The atmospheric model fiel...

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Bibliographic Details
Published in:Journal of Quaternary Science
Main Authors: Bigg, Grant R., Wadley, Martin R.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2001
Subjects:
Online Access:http://dx.doi.org/10.1002/jqs.628
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.628
https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.628
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Summary:Abstract The precipitation fields of a palaeoatmospheric general circulation model are used to derive estimates of the geographical distribution, and flux, of icebergs from the Laurentide, Fennoscandinavian and eastern Siberian ice‐sheets at the Last Glacial Maximum (LGM). The atmospheric model fields from LGM simulations using CLIMAP or Peltier (ICE‐4G) ice orography were studied, to test the sensitivity of the predicted flux. The estimated Northern Hemispheric LGM iceberg flux is 3500–4000 km 3 yr −1 , of which about 60% issued directly into the North Atlantic. The iceberg flux from the St Lawrence area is of similar significance to that issuing from Hudson Strait in all estimates. Both the North Pacific and the Arctic received substantial iceberg fluxes (ca. 700 km 3 yr −1 ), with relatively minor differences occurring between the two ice‐sheet reconstructions. Apparent discrepancies between Arctic deep‐sea core samples of ice‐rafted debris and our estimates of mean glacial iceberg flux may be ascribed to coastal trapping of bergs, the existence of floating ice tongues or a rapid exit of icebergs from the Arctic basin into the Greenland Sea through the Fram Strait. Copyright © 2001 John Wiley & Sons, Ltd.