Title 'Sticky spots' and subglacial lakes under ice streams of the Siple Coast, Antarctica
Author Sergienko, O.V.; Hulbe, C.L.
Author Affil Sergienko, O.V., Princeton University, Geophysical Fluid Dynamics Laboratory, Atmospheric and Oceanic Sciences Program, Princeton, NJ. Other: Portland State University
Source Annals of Glaciology, 52(58), p.18-22, . Publisher: International Glaciological Society, Cambridge, United Kingdom. ISSN: 0260-3055
Publication Date 2011
Notes In English. 29 refs. Ant. Acc. No: 91641. GeoRef Acc. No: 310216
Index Terms glacial geology; glacier flow; lakes; meltwater; models; simulation; thermodynamic properties; topography; water pressure; Antarctica; dynamics; ice movement; ice streams; numerical models; Siple Coast; steady-state processes; subglacial environment; subglacial lakes
Abstract Locations of subglacial lakes discovered under fast-moving West Antarctic ice streams tend to be associated with topographic features of the subglacial bed or with areas that have strong variations in basal conditions. Inversion of ice-stream surface velocity indicates that basal conditions under ice streams can be highly variable and that there can be widespread regions where basal traction is high. To seek an explanation for why lakes appear to be sited near areas with high basal traction, we use numerical models to simulate ice-stream dynamics, thermodynamics and subglacial water flow. We demonstrate that the ice flow over high basal traction areas produces favourable conditions for the ponding of meltwater. Energy dissipation associated with ice sliding over a region with high basal traction constitutes a water source supplying a lake, and ice-thickness perturbations induced by ice flow over variable traction create local minima in hydraulic potential. Variations in thermodynamic processes caused by such ice flow could be responsible for limiting the horizontal extent of the subglacial lakes.
URL http://www.igsoc.org/annals/v52/58/a58A083.pdf
Publication Type journal article
Record ID 65007347