Titre

Thufur formation in northern Iceland and its relation to holocene climate change

Année de publication

1998

Source

Permafrost and Periglacial Processes 9 347 365 4

ISSN
1045-6740
Résumé

This paper compares thufur formation in the northern volcanic zone of Iceland with that of other periglacial hummock forms. The aim of this work is to further the understanding of the extent of thufur in Iceland, in terms of cryogenic mechanisms related to specific edaphic conditions. Thufur may be considered to be hummocks, of a mainly minerogenic nature and specifically developed in volcanic loesses on drained basaltic rocks or openwork glacial or fluvio‐glacial substratum. They are thus connected to the oceanic cold climate as well as to the occurrence of volcanic loesses with specific physical properties resting on permeable substratum. Their development does not rely on either permafrost or a water table. Rather, they result from deep seasonal freezing, with exaggerated frost heave limited by snow accumulation along with the development of injection patterns along dilation cracks. Thufur may be considered as a subtype of hummock, or of raised‐centre non‐sorted polygons related to seasonal frost and snowdrift. In Iceland, the high geothermal gradient may, through exaggerated frost heave, enhance hummocky microrelief locally. Thufur expansion is related to the post‐Hypsithermal (Atlantic) climate degradation of the Holocene linked to orbital forcing. Thanks to tephro‐stratigraphy, it is possible to define several main episodes of thufur growth: around 4500 BP; after 2600 BP; prior to colonization (1104 AD); as well as two phases during the Little Ice Age. These growth phases are coherent with the pedoclimatic record on both sides of the North Atlantic. © 1998 John Wiley & Sons, Ltd.

Type de publication
  • journal
Type de document
  • article
Classification
 
Classification - Inist-CNRS
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
  • 4 - ecologie animale, vegetale et microbienne
Classification - Scopus
  • 1 - Physical Sciences
  • 2 - Earth and Planetary Sciences
  • 3 - Earth-Surface Processes
Classification - Science Metrix
  • 1 - economic & social sciences
  • 2 - social sciences
  • 3 - geography
Classification - Clarivate Analytics (Subject Category)
  • 1 - science
  • 2 - geology
  • 2 - geography, physical
Termes extraits

thufur; permafrost; hummock; loess; holocene; john wiley sons; periglac; tephra; thorarinsson; thufur formation; geothermal; peat; brunna; dauteuil; schunke; microrelief; basaltic; water table; aeolian; cnrs; northern iceland; iceland; zoltai; nupar; precipitation; dilation cracks; periglacial; southern iceland; frost heave; volcanic loesses; thufur growth; tephra layers; snow patch; myvatn lake; volcanic; glacier; seasonal frost; aluminium polymers; geothermal gradient; other sites; growth phases; hummocky microrelief; peat growth; dauteuil figure; particular reference; snow patches; finnish lapland; environmental change; heave; anthropogenic pressure; periglacial processes; cryogenic mechanisms; holocene climate; holocene climate changes; several sites; snow accumulation; high water retention; figure location; holocene climate change; thufur peuvent etre consideres comme; stratigraphical position; uneven thicknesses; periglacial deformation; leur apparition; loessic sedimentation; amorphous clays; institut francais; injection patterns; pattern ground; northern coast; edaphic conditions; ssure swarm; basaltic rocks; early holocene; permeable substratum; permafrost occurrence; central iceland; tundra polygons; villeneuve cedex; buttes gazonnees; recent lava; salix polaris; cryptogamic crust; alpine meadows; central injection; sides deforming; humus accumulation; little evidence; central part; pipkrake activity; coldest part; wettest part; liquefaction collapse; northern quebec; other regions; climate degradation; earth hummocks; volcanic activity; canadian journal; late weichselian; aeolian sedimentation; dilation; vegetation; wiley

Entité nommée
 
Entité nommée - Emplacement géographique
  • Svalbard
  • Caen
  • Rennes
  • Akureyri
  • Canada
  • Greenland
  • Europe
  • Lapland
  • New Zealand
  • France
  • Quebec
  • Iceland
  • Lille
Entité nommée - Organisme
  • University of Lille
  • University of Helsinki, Finland
  • Sons, Ltd.
  • East Greenland Current
  • Sons, Ltd
Entité nommée - Personne
Martine Bocquet; April May; Van Vliet-Lanoe; John Wiley; O. Bourgeois; B. Van Vliet-Lanoe; Carpentier; O. Dauteuil; June July; Stratigraphy; Schunke
ark:/67375/WNG-C9X0GRR2-G
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