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Coupling of ice‐shelf melting and buttressing is a key process in ice‐sheets dynamics
Author(s) -
Gagliardini O.,
Durand G.,
Zwinger T.,
Hindmarsh R. C. A.,
Le Meur E.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl043334
Subject(s) - ice shelf , lead (geology) , geology , ice sheet , coupling (piping) , mechanics , geophysics , sea ice , geomorphology , oceanography , materials science , physics , cryosphere , composite material
Increase in ice‐shelf melting is generally presumed to have triggered recent coastal ice‐sheet thinning. Using a full‐Stokes finite element model which includes a proper description of the grounding line dynamics, we investigate the impact of melting below ice shelves. We argue that the influence of ice‐shelf melting on the ice‐sheet dynamics induces a complex response, and the first naive view that melting inevitably leads to loss of grounded ice is erroneous. We demonstrate that melting acts directly on the magnitude of the buttressing force by modifying both the area experiencing lateral resistance and the ice‐shelf velocity, indicating that the decrease of back stress imposed by the ice‐shelf is the prevailing cause of inland dynamical thinning. We further show that feedback from melting and buttressing forces can lead to nontrivial results, as an increase in the average melt rate may lead to inland ice thickening and grounding line advance.