
Helena Alexanderson
Professor

Dynamics and retreat of the Late Weichselian Kongsfjorden ice stream, NW Svalbard
Författare
Summary, in English
Terrestrial cosmogenic nuclide dating in combination with detailed landform mapping in the Kongsf-jordhallet area, NW Svalbard, have provided new insight on configuration, dynamics, and deglaciation of the Late Weichselian Kongsfjorden ice stream. The minimum Late Weichselian ice surface elevation in Kongsfjorden was >449 m a.s.l. indicating considerably thicker ice and a steeper surface gradient than earlier suggested. For the adjacent inter-ice stream area an even steeper surface slope is reconstructed. The glacial landforms, as well as the surface exposure ages of erratic boulders at different elevations, suggest a gradual lowering of the ice surface. Deglaciation of the higher elevations was probably underway by 20.0 ka. At ca 16.6 ka a large moraine complex ('the Kongsfjorden moraine') was deposited close to the fjord mouth. The shape of the moraines, the steep ice surface gradient, as well as the correlation to fine laminated clay lacking ice rafted debris deposited in the trough beyond the moraine suggest that ice dynamics switched from ice-stream behaviour to a slower flowing outlet (tidewater) glacier. A Younger Dryas or Early Holocene advance of local valley glaciers is shown by moraine lobes cross-cutting the Late Weichselian lateral moraines. (C) 2013 Elsevier Ltd. All rights reserved.
Avdelning/ar
- Kvartärgeologi
Publiceringsår
2014
Språk
Engelska
Sidor
235-245
Publikation/Tidskrift/Serie
Quaternary Science Reviews
Volym
92
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Geology
Nyckelord
- Svalbard
- Surface exposure dating
- Ice stream dynamics
- Deglaciation
Aktiv
Published
Projekt
- Glacial history of Svalbard
ISBN/ISSN/Övrigt
- ISSN: 0277-3791