Helena Alexandersson

Helena Alexanderson

Professor

Helena Alexandersson

Late quaternary ice sheet history of northern Eurasia

Författare

  • JI Svendsen
  • Helena Alexanderson
  • VI Astakhov
  • I Demidov
  • JA Dowdeswell
  • S Funder
  • V Gataullin
  • M Henriksen
  • Christian Hjort
  • M Houmark-Nielsen
  • HW Hubberten
  • O Ingolfsson
  • M Jakobsson
  • Kurt Kjaer
  • E Larsen
  • H Lokrantz
  • JP Lunkka
  • A Lysa
  • J Mangerud
  • A Matiouchkov
  • A Murray
  • Per Möller
  • F Niessen
  • O Nikolskaya
  • L Polyak
  • M Saarnisto
  • C Siegert
  • MJ Siegert
  • RF Spielhagen
  • R Stein

Summary, in English

The maximum limits of the Eurasian ice sheets during four glaciations have been reconstructed: (1) the Late Saalian (> 140 ka), (2) the Early Weichselian (100-80 ka), (3) the Middle Weichselian (60-50 ka) and (4) the Late Weichselian (25-15 ka). The reconstructed ice limits are based on satellite data and aerial photographs combined with geological field investigations in Russia and Siberia, and with marine seismic- and sediment core data. The Barents-Kara Ice Sheet got progressively smaller during each glaciation, whereas the dimensions of the Scandinavian Ice Sheet increased. During the last Ice Age the Barents-Kara Ice Sheet attained its maximum size as early as 90-80,000 years ago when the ice front reached far onto the continent. A regrowth of the ice sheets occurred during the early Middle Weichselian, culminating about 60-50,000 years ago. During the Late Weichselian the Barents-Kara Ice Sheet did not reach the mainland east of the Kanin Peninsula, with the exception of the NW fringe of Taimyr. A numerical ice-sheet model, forced by global sea level and solar changes, was run through the full Weichselian glacial cycle. The modeling results are roughly compatible with the geological record of ice growth, but the model underpredicts the glaciations in the Eurasian Arctic during the Early and Middle Weichselian. One reason for this is that the climate in the Eurasian Arctic was not as dry then as during the Late Weichselian glacial maximum.

Ämne

  • Geology

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0277-3791