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

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • M. Horwath - , Professur für Geodätische Erdsystemforschung (Autor:in)
  • R. Dietrich - , Professur für Geodätische Erdsystemforschung (Autor:in)
  • M. Bässler - , Technische Universität Dresden (Autor:in)
  • U. Nixdorf - , Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (Autor:in)
  • D. Steinhage - , Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (Autor:in)
  • D. Fritsche - , Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (Autor:in)
  • V. Damm - , Federal Institute for Geosciences and Natural Resources (Autor:in)
  • G. Reitmayr - , Federal Institute for Geosciences and Natural Resources (Autor:in)

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

OriginalspracheEnglisch
Seiten (von - bis)17-30
Seitenumfang14
FachzeitschriftJournal of Glaciology
Jahrgang52
Ausgabenummer176
PublikationsstatusVeröffentlicht - 8 Sept. 2006
Peer-Review-StatusJa

Externe IDs

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

Schlagworte

Fächergruppen, Lehr- und Forschungsbereiche, Fachgebiete nach Destatis