Elmer/Ice News


Elmer/Ice at AGU2012

Written by Olivier Gagliardini on .

Here is a list of the known Elmer/Ice talks and posters that will be presented at the forthcoming AGU in San Francisco,  3-7 Dec 2012. Please, if your talk/poster is not listed, contact me (OG) and I will add your presentation.

Wednesday, December 05, 2012

8:00 AM-12:20 PM, Hall A-C (Moscone South), C31B. Modeling of Glaciers and Ice Sheets I - Posters

  • C31B-0591. Capabilities and performance of the new generation icesheet model Elmer/Ice. O. Gagliardini; T. Zwinger; G. Durand; L. Favier; B. de Fleurian; F. Gillet-chaulet; H. Seddik; R. Greve; M. Mallinen; C. Martin; P. Raback; J. Ruokolainen; M. Schäfer; J. Thies
  • C31B-0592. Full Stokes or shallow ice approximation? Comparing the ice flow dynamics at the Shirase Drainage Basin, Antarctica. H. Seddik; R. Greve; T. Zwinger; S. Sugiyama
  • C31B-0597. Investigation of a new approach for the modelling of subglacial hydrology. B. de Fleurian; O. Gagliardini; G. Durand; E. Le Meur; D. Mair; T. Zwinger
  • C31B-0606. A simple method to assimilate both surface and bedrock data into an ice-sheet model. G. Durand; F. Gillet-chaulet

1:40 PM-3:40 PM, 3007 (Moscone West), C33E. Modeling of Glaciers and Ice Sheets II   

  • C33E-05. The dynamic response of Pine Island Glacier to a calving event inferred from two higher-order models. L. Favier; S.L. Cornford; G. Durand; O. Gagliardini; T. Zwinger

4:00 PM-6:00 PM, 3007 (Moscone West), C34A. Modeling of Glaciers and Ice Sheets III

  • C34A-01. Stable grounding lines on retrograde slopes. (Invited) G.H. Gudmundsson; J. Krug; L. Favier; G. Durand; O. Gagliardini

Thursday, December 06, 2012

3:55 PM-5:55 PM, 3002 (Moscone West), C43F. Cryospheric Contribution to Sea Level Rise: Current Estimates and Projections I (Video On-Demand)

  • C43F-06. Comparative forecast simulations of the Greenland icesheet using Elmer/Ice and GRISLI C. Ritz; F. Gillet-chaulet; O. Gagliardini; A. Quiquet; G. Durand; V. Peyaud

Friday, December 07, 2012

1:40 PM-6:00 PM, Hall A-C (Moscone South), C53B. Cryospheric Contribution to Sea Level Rise: Current Estimates and Projections II Posters

  • C53B-0840. Semi-empirical and process-based global sea level projections J.C. Moore; A. Grinsted; T. Zwinger; S. Jevrejeva





Parameterization of lateral drag in ice flowline models

Written by Olivier Gagliardini on .

cross section2Adhikari and Marshall (2012) employ Elmer/Ice model to identify two distinct sources of lateral drag (i.e., geometry-induced and slip-induced drag). Effects of both sources of lateral drag have been systematically parameterized for flowline models of glacier dynamics.

Abstract: Given the cross-sectional geometry of a valley glacier, effects of lateral drag can be parameterized in flowline models through the introduction of Nye shape factors. Lateral drag also arises due to lateral variability in bed topography and basal flow, which induce horizontal shear stress and differential ice motion. For glaciers with various geometric and basal conditions, we compare three-dimensional Stokes solutions to flowline model solutions to examine both sources of lateral drag. We calculate associated correction factors that help flowline models to capture the effects of lateral drag. Such parameterizations provide improved simulations of the dynamics of narrow, channelized, fast-flowing glacial systems. We present an example application for Athabasca Glacier in the Canadian Rocky Mountains.


Relationship between age and depth at ice divides

Written by Olivier Gagliardini on .

isochronesIn Martìn and Gudmundsson (2012), effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides is investigated using Elmer/Ice. 

Abstract: Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady state with a fully developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice flow on the age-versus-depth relationship at ice divides by using a full Stokes thermomechanical model with a non-linear anisotropic constitutive relation between stress and strain rates. We compare our results with analytical approximations commonly employed in age–depth predictions, such as the Dansgaard and Lliboutry approximations. We show that these approximations systematically underestimate the age of ice at fully developed divides by as much as one order of magnitude. We also show that divides with fully developed fabric are ideal locations for ice-core extraction because ice under them can be up to one order of magnitude older than ice at the same depth at the flanks. In addition, these divides have a distinctive morphological structure that allows them to be clearly identified from satellite imagery or ground-penetrating radar data.

Elmer / Ice project © 2012 -- Conception : iGrafic