Surface rolls are characteristic features of both the Ellesmere ice shelf and the floating ice islands derived from it. These surface features are described and their origin and evolution discussed. Various theories of origin are considered which involve such forces as pressure from the polar pack, movement of glaciers, temperature variations, tidal movements and wind. Of these, wind action appears the most likely to have caused the rolls, and it is suggested that their development was analogous to the formation of seif dunes in desert. "They should be regarded as fossil snow dunes that have been perpetuated by the annual drainage of melt-water."
ANDABSTRACT. T he results of 10 yea rs ' (1958-68 ) record of accumul ation a nd a bl a tion fro m the W a rd Hunt ice rise a nd of 3 years ' ( 1965-68) reco rd from the Wa rd Hunt J ce Shelf arc presented. The net mass ba la n ces on the ice rise for the 3 years 1962-65 a re positive, whil e the net mass balances m easured in the other yea rs o n both ice rise a nd ice shelf a re a ll negative. Ne tto-Massenbi la n zen a ll er an d eren J a hre sowo hl fur di e Eisaufwolbung wie feir das E isschelf nega ti v sind. REsuME INTRODU CTIONSince the recogni tion in ' 950 that ice shel ves occur off the north coast of Ell esmere Island (K oenig and others, 1952 ), there has been specu lation on whether they should be considered as relict features or as essentially the product of present climatic conditions. Field work in '953-54 showed that the Ward Hunt I ce Shelfin its most recent hi tory has undergone a long period of net ablation (Hattersley-Sm ith and others, 1955 ) ' This was evident from the heavy concentration of wind-blown dust at the surface a nd from th e discovery of debt"is resting on th e ice from one of R . E. P eary's overnigh t cam ps of ' 906, since when th ere had evid ently b een no net accumulation. Both the "Vard Hunt I ce Shelf and the ice rise showed considerable net surface ablation for the budget year ' 953-54; at on e pole on the ice shelf this amounted to as much as 630 mm water . In the four summ ers from 1955 to 1958 th e total n et abla tion on the ice shelf amounted to more than 1 350 mm water (C ra ry, ' 959). Further work on the ice shelf a nd ice rise showed net surface ablatio n of from 70 to 200 mm water in both th e 1958-59 and t959-60 budget years (Lotz, 196 1; Lister, 1962 ; Sagar, 1962 ) . In the winter of ' 96 , -62 massive cal ving reduced the area of the ,,yard Hunt I ce Shelf by abo ut 600 km2 ; a strip of the ice shelf up to 8 km wide had moved to sea along a line back to the northern edge of the Ward Hunt ice rise (Hattersley-Smith , ' 963 ). The part of the ice shelf where the 1959-60 observations had been made was removed , but th e ' 959-60 grid of poles on the "Vard Hun t ice rise was unaffected (Fig. I).Since 1963 we have cont inu ed to make accumulation and ablation m easurements each spring at the original poles on th e ice rise, nearly all of whi ch are still standing, and since 1966 we have made similar measurem ents at a 0.9 km square grid of 100 poles that were set in the ice shelf, 5 km east of Ward Hunt I sla nd , in 1965-66 (Fig. I). I n this paper th e results of 10 years' ( ' 958-68) records on the ice rise an d 3 years ' ( 1965-68) records on th e ice shelf are analysed.
Air photographs show that the Otto Glacier in northwestern Ellesmere Island started to surge sometime between 1950 and 1959, with the result that the terminus advanced about 3 km as a floating ice tongue. Maps prepared from the 1959 photographs and from additional photographs taken in 1964 show a further advance of 2-3 km. Information from a subglacial relief map of the terminal part of the glacier, constructed from the results of radio-depth sounding over the glacier in 1966, may have a bearing on the mechanism of glacier surges. Other glaciers in northern Ellesmere Island show features indicative of past surges.
NORTHERN ELLESMERE ISLAND,1953 AND 1954 1952 the US. Air Force made the first landing on the ice island T3 to set up a weather station, which became a base for research in oceanography, hydrography, glaciology, and geophysics until May 1954 when the station was temporarily aband0ned.l Flying from T3 in May l952, Lt.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.