Open AccessEvolution of a coupled marine ice sheet–sea level model
Author(s) -
Gomez Natalya,
Pollard David,
Mitrovica Jerry X.,
Huybers Peter,
Clark Peter U.
Publication year - 2012
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011jf002128
Subject(s) - geology , ice sheet , ice sheet model , sea ice , ice shelf , lead (geology) , sea level , forcing (mathematics) , antarctic ice sheet , ice stream , climatology , oceanography , geophysics , cryosphere , geomorphology
We investigate the stability of marine ice sheets by coupling a gravitationally self‐consistent sea level model valid for a self‐gravitating, viscoelastically deforming Earth to a 1‐D marine ice sheet‐shelf model. The evolution of the coupled model is explored for a suite of simulations in which we vary the bed slope and the forcing that initiates retreat. We find that the sea level fall at the grounding line associated with a retreating ice sheet acts to slow the retreat; in simulations with shallow reversed bed slopes and/or small external forcing, the drop in sea level can be sufficient to halt the retreat. The rate of sea level change at the grounding line has an elastic component due to ongoing changes in ice sheet geometry, and a viscous component due to past ice and ocean load changes. When the ice sheet model is forced from steady state, on short timescales (<∼500 years), viscous effects may be ignored and grounding‐line migration at a given time will depend on the local bedrock topography and on contemporaneous sea level changes driven by ongoing ice sheet mass flux. On longer timescales, an accurate assessment of the present stability of a marine ice sheet requires knowledge of its past evolution.