Modeling the Controls on the Front Position of a Tidewater Glacier in Svalbard

Frontiers in Digital Humanities

Lapazaran, Javier J.¹  Puczko, Darek¹  Otero, Jaime¹  Finkelnburg, Roman⁴  Welty, Ethan⁴  Navarro, Francisco J.⁴ 

[1] Department of Applied Mathematics, Universidad PolitéInstitute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA;Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland;cnica de Madrid, Madrid, Spain

关键词: Tidewater glacier;    Hansbreen;    Svalbard;    Calving;    terminus position;    modelling;   

DOI  :  10.3389/feart.2017.00029

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Calving is an important mass-loss process at ice sheet and marine-terminating glacier margins, but identifying and quantifying its principal driving mechanisms remains challenging. Hansbreen is a grounded tidewater glacier in southern Spitsbergen, Svalbard, with a rich history of field and remote sensing observations. The available data make this glacier suitable for evaluating mechanisms and controls on calving, some of which are considered in this paper. We use a full-Stokes thermomechanical 2D flow model (Elmer/Ice), paired with a crevasse-depth calving criterion, to estimate Hansbreen’s front position at a weekly time resolution. The basal sliding coefficient is re-calibrated every four weeks by solving an inverse model. We investigate the possible role of backpressure at the front (a function of ice mélange concentration) and the depth of water filling crevasses by examining the model’s ability to reproduce the observed seasonal cycles of terminus advance and retreat. Our results suggest that the ice-mélange pressure plays an important role in the seasonal advance and retreat of the ice front, and that the crevasse-depth calving criterion, when driven by modelled surface meltwater, closely replicates observed variations in terminus position. These results suggest that tidewater glacier behavior is influenced by both oceanic and atmospheric processes, and that neither of them should be ignored.

【 授权许可】

CC BY