Calving on tidewater glaciers amplified by submarine frontal melting 1Scott Polar Research Institute, University of Cambridge, Cambridge, UK
28 Jan 2013
2Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI, USA
Received: 17 Jun 2012 – Published in The Cryosphere Discuss.: 08 Aug 2012Abstract. While it has been shown repeatedly that ocean conditions exhibit an important
control on the behaviour of grounded tidewater glaciers, modelling studies
have focused largely on the effects of basal and surface melting. Here, a
finite-element model of stresses near the front of a tidewater glacier is
used to investigate the effects of frontal melting on calving, independently
of the calving criterion used. Applications of the stress model to idealized
scenarios reveal that undercutting of the ice front due to frontal melting
can drive calving at up to ten times the mean melt rate. Factors which cause
increased frontal melt-driven calving include a strong thermal gradient in
the ice, and a concentration of frontal melt at the base of the glacier.
These properties are typical of both Arctic and Antarctic tidewater glaciers.
The finding that frontal melt near the base is a strong driver of calving
leads to the conclusion that water temperatures near the bed of the glacier
are critically important to the glacier front, and thus the flow of the
glacier. These conclusions are robust against changes in the basal boundary
condition and the choice of calving criterion, as well as variations in the
glacier size or level of crevassing.
Revised: 01 Nov 2012 – Accepted: 28 Nov 2012 – Published: 28 Jan 2013
Citation: O'Leary, M. and Christoffersen, P.: Calving on tidewater glaciers amplified by submarine frontal melting, The Cryosphere, 7, 119-128, doi:10.5194/tc-7-119-2013, 2013.