|
Titel |
Influence of ice-sheet geometry and supraglacial lakes on seasonal ice-flow variability |
VerfasserIn |
I. Joughin, S. B. Das, G. E. Flowers, M. D. Behn, R. B. Alley, M. A. King, B. E. Smith, J. L. Bamber, M. R. Broeke, J. H. Angelen |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1994-0416
|
Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 7, no. 4 ; Nr. 7, no. 4 (2013-07-26), S.1185-1192 |
Datensatznummer |
250017994
|
Publikation (Nr.) |
copernicus.org/tc-7-1185-2013.pdf |
|
|
|
Zusammenfassung |
Supraglacial lakes play an important role in establishing hydrological
connections that allow lubricating seasonal meltwater to reach the base of
the Greenland Ice Sheet. Here we use new surface velocity observations to
examine the influence of supraglacial lake drainages and surface melt rate
on ice flow. We find large, spatially extensive speedups concurrent with
times of lake drainage, showing that lakes play a key role in modulating
regional ice flow. While surface meltwater is supplied to the bed via a
geographically sparse network of moulins, the observed ice-flow enhancement
suggests that this meltwater spreads widely over the ice-sheet bed. We also
find that the complex spatial pattern of speedup is strongly determined by
the combined influence of bed and surface topography on subglacial water
flow. Thus, modeling of ice-sheet basal hydrology likely will require
knowledge of bed topography resolved at scales (sub-kilometer) far finer
than existing data (several km). |
|
|
Teil von |
|
|
|
|
|
|