Laboratory observations of sediment entrainment by freezing supercooled water

Auteur(s) et Affiliation(s)

COOK, S.J.

Centre for Glaciology, Inst. Geography and Earth Sciences, Univ. Wales, Aberystwyth, Royaume-Uni

KNIGHT, P.G.

Research Inst. for Environment, Physical Sciences and Applied Mathematics (EPSAM), Univ., Staffordshire, Keele, Royaume-Uni

School of Physical and Geographical Sciences, Univ., Keele, Royaume-Uni

KNIGHT, D.A.

School of Physical and Geographical Sciences, Univ., Keele, Royaume-Uni

WALLER, R.I.

Research Inst. for Environment, Physical Sciences and Applied Mathematics (EPSAM), Univ., Staffordshire, Keele, Royaume-Uni

School of Physical and Geographical Sciences, Univ., Keele, Royaume-Uni

Description :
The AA. present results of laboratory experiments designed to test a hypothesis that silt is preferentially entrained by freezing supercooled water and that silt-dominance is, therefore, a diagnostic indicator of glaciohydraulic supercooling. They performed experiments to simulate 2 freezing processes : filtration of sediment-laden water through frazil ice; and turbulent supercooling and subsequent freezing of sediment-laden water. Different mixtures of particle sizes (sand, silt and clay) were added to the parent water. The results indicate that, contrary to previous suggestions, these processes do not lead to the preferential entrainment of silt in the resulting ice. The silt-dominated character of basal ice types associated with supercooling may result from other controls such as a silt-dominated sediment supply or subglacial water flow rates, rather than the freezing process.

Type de document :
Article de périodique

Source :
Geografiska annaler. Series A. Physical geography, issn : 0435-3676, 2012, vol. 94, n°. 3, p. 351-362, nombre de pages : 12, Références bibliographiques : 47 ref.

Date :
2012

Editeur :
Pays édition : Suede, Stockholm, Svenska sällskapet för antropologi och geografi

Langue :
Anglais