Glacier Movement in North-East Greenland, 1949: With a Note on Some Subglacial Observations

Abstract

ABSTRACT. Work on the Froya Gletscher, N.E. Greenland, appears to substantiate the evidence already brought forward for the irregular flow of glaciers over shor t periods. It appears possible to correlate the daily temperature regime with the flow of some "polar glaciers." The distribution of thrust planes seems to have no noticeable effect on the flow. It is suggested that Block-Schollell movement may underlie the jerky motion of some of even the slower moving g laciers. A subglacial stream bed on the Skille Gletscher was explored from the snout for a distance of 500 m. It is estimated that at the farthest point the ice was 76 m. thick. There appears to be good observational eviden ce for de Martonne's theory of medial moraines extending to the bed of the glacier.ZUSAMMENFASSUNG. Arbeiten am Froya Glets cher, Nord Ost Gronland, scheinen den bereits hervorgebrachten Beweis, dass Gletscher in kurzen Zeitraumen unregelmassig fliessen, zu bestatigen. Es scheint moglich zu sein, die tagliche Temperatur-Haushalt mit der Stromung einiger "Polar-Gletscher" in Zusammenhang bringen zu konnen. Die Verteilung von Schubflachen scheint keinen merklichen Einfluss auf die Stromung zu haben. Es wird darauf hingewiesen, dass die Block-Schollen-Bewegung der stossweisen Bewegung einiger, selbst langsam fliessen den G le tscher, zu Grunde liegen mag. Ein subglaziales Strombett am Ski lle Gletscher wurde von der Spitze ausgeh end eine 500 m Strecke weit untersucht. Es wurde geschatzt, dass das E is an der entferntesten Stelle 76 m dick war. Die Martonnesche Theorie, dass mittlere Moranen si ch bis zum Bett des Gletschers erstrecken, sehein t durch Beobachtungen bestatigt zu werden.

Multi-decadal reduction in glacier velocities and mechanisms driving deceleration at polythermal White Glacier, Arctic Canada

“…Observations indicating that glaciers do not flow at constant speeds, but rather fluctuate on timescales of hours to days, were made as early as the 1930s on Himalayan glaciers (Finsterwalder and Pillewizer, 1939) and South Crillon Glacier, Alaska (Washburn and Goldthwait, 1937). That polar glaciers could also show surface velocity fluctuations on the order of hours was first demonstrated by Battle (1951) at Fröya Glacier in Northeastern Greenland. The notion that meltwater delivered to the glacier bed will reduce friction, increase water pressure and thus promote sliding of the ice over the bed (basal sliding), has been used to explain the short-term (hourly to daily) fluctuations of surface velocities for many temperate glaciers (Iken and others, 1983;Kamb and others, 1985;Iken and Bindschadler, 1986) and polythermal glaciers at higher latitudes (Iken, 1974;Bingham and others, 2003;Copland and others, 2003a;Rippin and others, 2005).…”

Advances in monitoring glaciological processes in Kalallit Nunaat (Greenland) over the past decades

“…Over the first half of the 20 th century, reconstructions of GrIS surface mass balance (SMB), which is the difference between accumulation and ablation without iceberg calving and thinning, show that following their initial retreat from the LIA maximum, glaciers remained relatively stable [22,23]. Over the later half of the 20 th century, observations on the GrIS increased, mass balance estimates were recorded, and new in-situ and remote sensing methods became available to monitor glaciers continuously (Fig 1) [24][25][26][27]. Starting in the 1990s, marine-terminating glaciers around the GrIS began to accelerate, thin and retreat, which has been attributed to a change in climate and is also apparent in the SMB estimates (Fig 1) [28].…”