 |
| Titel |
Basal crevasses in Larsen C Ice Shelf and implications for their global abundance |
| VerfasserIn |
A. Luckman, D. Jansen, B. Kulessa, E. C. King, P. Sammonds, D. I. Benn |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 6, no. 1 ; Nr. 6, no. 1 (2012-01-24), S.113-123 |
| Datensatznummer |
250003378
|
| Publikation (Nr.) |
 copernicus.org/tc-6-113-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Basal crevasses extend upwards from the base of ice bodies and can penetrate
more than halfway through the ice column under conditions found commonly on
ice shelves. As a result, they may locally modify the exchange of mass and
energy between ice shelf and ocean, and by altering the shelf's mechanical
properties could play a fundamental role in ice shelf stability. Although
early studies revealed that such features may be abundant on Antarctic ice
shelves, their geometrical properties and spatial distribution has gained
little attention. We investigate basal crevasses in Larsen C Ice Shelf using
field radar survey, remote sensing and numerical modelling. We demonstrate
that a group of features visible in MODIS imagery are the surface
expressions of basal crevasses in the form of surface troughs, and find that
basal crevasses can be generated as a result of stresses well downstream of
the grounding line. We show that linear elastic fracture mechanics modelling
is a good predictor of basal crevasse penetration height where stresses are
predominantly tensile, and that measured surface trough depth does not
always reflect this height, probably because of snow accumulation in the
trough, marine ice accretion in the crevasse, or stress bridging from the
surrounding ice. We conclude that all features visible in MODIS imagery of
ice shelves and previously labelled simply as "crevasses", where they are
not full thickness rifts, must be basal crevasse troughs, highlighting a
fundamental structural property of many ice shelves that may have been
previously overlooked. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|