Modeling of Store Gletscher's calving dynamics, West Greenland, in response to ocean thermal forcing

• Published in: Geophysical Research Letters
• Main Authors: Morlighem, M, Bondzio, J, Seroussi, H, Rignot, E, Larour, E, Humbert, A, Rebuffi, S
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2016
• Subjects: Life Below Water; glaciology; calving; ice-ocean interactions; Store Gletscher; inverse modeling; Meteorology & Atmospheric Sciences; glacier; Greenland
• Online Access: https://escholarship.org/uc/item/05d615kj; https://escholarship.org/content/qt05d615kj/qt05d615kj.pdf; https://doi.org/10.1002/2016gl067695

Glacier-front dynamics is an important control on Greenland's ice mass balance. Warmer ocean waters trigger ice-front retreats of marine-terminating glaciers, and the corresponding loss in resistive stress leads to glacier acceleration and thinning. Here we present an approach to quantify the sensitivity and vulnerability of marine-terminating glaciers to ocean-induced melt. We develop a plan view model of Store Gletscher that includes a level set-based moving boundary capability, a parameterized ocean-induced melt, and a calving law with complete and precise land and fjord topographies to model the response of the glacier to increased melt. We find that the glacier is stabilized by a sill at its terminus. The glacier is dislodged from the sill when ocean-induced melt quadruples, at which point the glacier retreats irreversibly for 27 km into a reverse bed. The model suggests that ice-ocean interactions are the triggering mechanism of glacier retreat, but the bed controls its magnitude.