Modeling of subglacial hydrological development following rapid supraglacial lake drainage

Authors Organisations
  • C. F. Dow(Author)
    Prifysgol Abertawe | Swansea University
    NASA Goddard Space Flight Center
  • B. Kulessa(Author)
    Prifysgol Abertawe | Swansea University
  • I. C. Rutt(Author)
    Prifysgol Abertawe | Swansea University
  • V. C. Tsai(Author)
    California Institute of Technology
  • S. Pimental(Author)
    Trinity Western University
  • Samuel Doyle(Author)
  • Dirk Van As(Author)
    Geological Survey of Denmark and Greenland
  • K. Lindbäck(Author)
    Uppsala University
  • R. Pettersson(Author)
    Uppsala University
  • G. A. Jones(Author)
    Prifysgol Abertawe | Swansea University
  • Alun Hubbard(Author)
Type Article
Original languageEnglish
Pages (from-to)1124-1147
Number of pages21
JournalJournal of Geophysical Research: Earth Surface
Volume120
Issue number6
DOI
Publication statusPublished - Jun 2015
Links
Show download statistics
View graph of relations
Citation formats

Abstract

The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections.