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Movement of the Ward Hunt Ice Shelf, Ellesmere Island, N.W.T., Canada

  • E. Dorrer (a1)

Abstract

The movement at a marginal location on the Ward Hunt Ice Shelf, northern Ellesmere Island, was determined by repeated survey measurements with theodolite and geodimeter. The purpose and duration of the field work, and reduction of the observational data are described, and the resulting mean ice velocity of 0.53 m year-1 is discussed. Strain-rates of a 1 km by 1 km deformation figure are determined. The parameters n and B of Glen’s power flow law are determined by using the equations given by Nye and Weertman. The results are compared with experimental data. Computed ice stresses show that the “ridge-and-trough" structure on the ice shelf surface is not originated by internal ice forces. The elevations of all survey markers have been determined from vertical-angle measurements, and the peculiarities of atmospheric refraction in near-surface layers are discussed.

Résumé

Le mouvement sur le bord de la Ward Hunt Ice Shelf au nord de Ellesmere Island, a été déterminé par des mesures répétées au théodolite et au géodimètre. On décrit le but et la durée du travail sur le terrain et la mise en forme des données d’observation, on discute la vitesse moyenne qui en résulte de 0,53 m par an. On détermine la répartition des tensions grâce à un polygone de déformation de 1 km sur 1 km. Les paramètres n et B de la loi puissance de Glen pour l’écoulement sont déterminés en usant les équations données par Nye et Weertman. Les résultats sont comparés aux données de F expérience. Le calcul des efforts dans la glace montre que la structure en creux cl rides de la surface de la calotte glaciaire n’a pas pour origine des forces internes dans la glace. L’altitude de toutes les balises a été déterminée à partir de mesures d’angles verticaux, et les particularités de la réfraction atmosphérique dans les niveaux voisins de la surface sont discutées.

Zusammenfassung

Die Bewegung eines randnahen Gebietes auf dem Ward Hunt Ice Shelf, nördliche Ellesmere Island, Kanada, wurde durch wiederholte Vermessungen mit Theodolit und Geodimeter bestimmt. Der Zweck und die Dauer der Feldarbeiten, sowie die Reduktion der Beobachiungsdalen werden beschrieben, die resultierende mittlere Eisgeschwindigkeit von 0,53 m pro Jahr wird diskutiert. Die jährlichen Deformationen eines 1 km X 1 km grossen Vierecks werden bestimmt. Die Parameter n und B fur Glens Fiiessgesetz werden durch Anwendung der Gleichungen von Nye und Weertman ermittelt. Die Ergebnisse werden mit experimentell bestimmten Werten verglichen. Die berechneten Eisspannungen zeigen, dass die Wcllenstruktur an der Schelfeisoberfläche nicht von inneren Eiskräften hervorgerufen wird. Die Höhen aller Yermessungspunkte wurden aus Vertikidwinkelmessungen bestimmt. Die Eigentümlichkeiten der atmosphärischen Refraktion in oberflächennahen Luftschichten werden diskutiert.

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Copyright

References

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Brocks, K. 1954 Eine räumlich integrierende optische Methode für die Messung vertikaler Temperatur– und Wasserdampfgradienten in der untersten Atmosphäre.Archiv für Meteorologie, Geophysik und Bioklimatologit, Ser, A, Bd. 6, Ht. 3–4, p. 370402.
Budd, W. 1966 The dynamics of the Amery Ice Shelf. Journal of Glaciology, Vol. 6, No. 45, p. 33558.
Crary, A.P. 1958 Arctic ice island and ice shelf studies. Part I. Arctic, Vol. II, No. I p. 242.
Faig, W. Unpublished. A report on the triangulation–trilateration surveys in 1964 and 1965 at the Ward Hunt Ice Shelf. [Report of the Surveying Engineering Division, University of New Brunswick, 1965]
Smith, G. 1957 The rolls on the Ellesmere ice shelf. Arctic, Vol. 10, No. 1, p. 32—44.
Smith, G. 1963 The Ward Hunt Ice Shelf: recent changes of the ice front. Journal of Glaciology, Vol. 4, No. 34, p. 41524.
Koenig, L.S. 1952 Arctic ice islands, [by] Koenig, L.S.,Greenaway, K.R.,Moira, Dunbar,Hattersley–Smith, G... Arctic, Vol. 5, No. 2, p. 66103.
Konecny, G. Faig, W. 1966 Studies of ice movement on the Ward Hunt Ice Shelf by means of triangulation·trilateration. Arctic, Vol. 19, No. 4, p, 33742.
Lijequist, G. 1964 Special studies. B. Refraction phenomena in the polar atmosphere (Maudheim, 71° 03’ S, 10° 56’ W). Norwegian–British–Swedish Antarctic Expedition, 1949–52. Scientific Results, Vol. 2, Part 2B p. 89120.
Lyons, J.B. Ragle, R.H. 1962 Thermal history and growth of the Ward Hunt Ice Shelf. Union Géodésique et Géophysique Internationale. Association Internatinnale d’Hydrologie Scientifique. Commission des feiges et Glaces.Colloque d’Obergurgl, 10–9–18–9 1962, p. 8897.
Mellor, M. Testa, R. 1969[a] Creep of ice under low stress. Journal of Giaciology, Vol. 8, No. 52, p. 14752.
Mellor, M. Testa, R. 1969[b] Effect of temperature on the creep of ice. Journal of Giaciology, Vol. 8, No. 52, p. 13145
Nutt, D.C. 1966 The drift ofice island W H–5. Arctic, Vol. 19, No. 3, p. 24462.
Nye, J.F. 1959 A method of determining the strain–rate tensor at the surface of a glacier. Journal of Giaciology, Vol. 3, No. 25, p. 40919.
Nye, J.F. 1965 The flow of a glacier in a channel of rectangular, elliptic or parabolic cross–section, Journal of Glaciology, Vol. 5, No. 41, p. 66190.
Weertman, J. 1957 Deformation of floating ice shelves. Journal of Giaciology, Vol. 3, No. 21, p. 3842.

Movement of the Ward Hunt Ice Shelf, Ellesmere Island, N.W.T., Canada

  • E. Dorrer (a1)

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