Nivlisen, an Antarctic ice shelf in Dronning Maud Land: Geodetic-glaciological results from a combined analysis of ice thickness, ice surface height and ice flow observations

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • M. Horwath - , Chair of Geodetic Earth System Research (Author)
  • R. Dietrich - , Chair of Geodetic Earth System Research (Author)
  • M. Bässler - , TUD Dresden University of Technology (Author)
  • U. Nixdorf - , Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research (Author)
  • D. Steinhage - , Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research (Author)
  • D. Fritsche - , Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research (Author)
  • V. Damm - , Federal Institute for Geosciences and Natural Resources (Author)
  • G. Reitmayr - , Federal Institute for Geosciences and Natural Resources (Author)

Abstract

Extensive observations on Nivlisen, an ice shelf on Antarctica’s Atlantic coast, are analyzed and combined to obtain a new description of its complex glaciological regime. We generate models of ice thickness (primarily from ground-penetrating radar), ellipsoidal ice surface height (primarily from ERS-1 satellite altimetry), freeboard height (by utilizing precise sea surface information) and ice-flow velocity (from ERS-1/-2 SAR interferometry and GPS measurements). Accuracy assessments are included. Exploiting the hydrostatic equilibrium relation, we infer the ‘apparent air layer thickness’ as a useful measure for a glacier’s density deviation from a pure ice body. This parameter exhibits a distinct spatial variation (ranging from ≈2 to ≈16m) which we attribute to the transition from an ablation area to an accumulation area. We compute mass-flux and mass-balance parameters on a local and areally integrated scale. The combined effect of bottom mass balance and temporal change averaged over an essential part of Nivlisen is –654 ± 170 kg m–2 a–1, which suggests bottom melting processes dominate. We discuss our results in view of temporal ice-mass changes (including remarks on historical observations), basal processes, near-surface processes and ice-flow dynamical features. The question of temporal changes remains open from the data at hand, and we recommend further observations and analyses for its solution.

Details

Original languageEnglish
Pages (from-to)17-30
Number of pages14
JournalJournal of Glaciology
Volume52
Issue number176
Publication statusPublished - 8 Sept 2006
Peer-reviewedYes

External IDs

Scopus 33744744719
ORCID /0000-0001-5797-244X/work/142246495

Keywords

DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis