Aspects of the Glaciology of Meighen Island, Northwest Territories, Canada

Abstract

ABSTRACT. l\ l eighen Is la nd lies in the centre of th e north coast of th e Q ueen E liza beth Isla nds a nd fronts o n the Arct ic O cean. An ice cap of a bo ut 76 km . 2 covers a bou t one-te n t h o f the isla nd . Its g reatest thickness of 150 m . occurs under th e su mm it, nea r th e sou th en d , whi ch was 268 m . above sea -l evel in 1960 . T he northern ha lf of the ice cap is less th a n 30 m. th ick ; a nd th e to ta l volum e is of th e o rd er of 2, 000 X 10 6 m .l.Precip ita ti o n is low in th e n o r thern Queen E liza beth Isla nds, a n d M eig hen Isla nd lies in a n a rea wh ere sum mer te m pera tures a re lowest. I n th e win te rs of 1959-60, 1960-6 1 a nd 196 1-62 , th e snow accumu la tio n was 12' 6 , 18· 2 and 14 ' I cm . of wa ter eq u iva lent . Som e snowfa ll re m a in ed on the hig he r p a rt of th e ice cap in th e cold su mmer of 196 1 ; bu t the ice ca p d imi n ished in volu me in ea ch yea r ; b y 36 X 10 6 , 72 X 10 6 , 22 X 10 6 a nd 9 1 X 10 6 m . l in th e 1959, 1960, 1961 a nd 1962 abla t io n seasons.I f th e con d itions of these fo ur seaso ns were m a inta ined t he ice cap wou ld d isappea r in a bo ut 100 yr. H owever, a rad io-ca rbon datin g of a saxifrage ex posed by the retrea t of th e ice from a sma ll nuna tak n ea r the nort hern edge ga ve a d a te o f less tha n 100 yr. , a nd it a ppea rs that th e ex iste nce of th e ice cap migh t be sensitively rel a ted to recent cl im a ti c cha nge.Ca refu l su rveys were m a de in 1959. 1960 and Ig6 1 in a n a ttempt to d etect movement in th e ice cap. U nequi voca l ev idence is no t ava ila b le from th ese surveys; bu t the stake n etwo rk has been m a inta in ed a nd a noth er su rvey has recen tly b een completed. R ESUME. "/stJecfs de La gLacioLogie dans riLe Meighell ( T. du .N. -D. ). S itu ee au cent re d e la cote nord des iles d e la R e in e-Elisab elh , I' il e M e ig hen fa it face a I'ocean A rct iqu e . E IIc est reco uvert e, sur cm,iron u n d izieme ell' sa surface. d ' un e ca lo tte glac ia ire e1 e quel que 76 kil omet res can es . La g la ce a tleint sa p lus g ra nd e ep a isse ur ( 150 m e tres) so us le po i11l c u lm inant , p res d e I' ex t rrm it c sud . et do nt I' a ltitude <'ta it e1e 268 m e tres en Ig60 . Dans la mo iti <' no rd e1 e la ca lo tte, la glace a mo ins e1e 30 metr es d 'c pa isseur. La ca lo tte con t ien t a peu pres 2000 X 100 m e tres cu bes d e g lace.La prec ip ita tion es t fa ib lc d a ns la pani e no rd des il es de la R e in e-E lisa bcth, et I' ile l\1e ighen se tro u ve da ns u n e reg ion 011 les te mj: c ra tu res d 'e te son t les p lus basscs . A u co ur's des hivers I 959-60, Ig60-6 1 e t Ig6 1 62 . la couche d c ne ige accumu lee eq u iva lait a 12.6, 18,2 e t 14. 1 cent im etres d 'ea u . ' 11 en res tai l UII peu sur la pa ni c supe r ie u re de la ca lott e durant r e te fraid d e Ig6 1. :\ Ia is a u COlJl'S d es sa isons d 'ab lation (eva pora t ion et fu sion d e la g lace) d e Ig59, Ig60. 196 1 et Ig62 , le vo lu:TI C d e la ealo tl e a dim...

The Meighen Ice Cap, Arctic Canada: Accumulation, Ablation and Flow

“…Accumulation Table I lists the accumulation data. Values for 1959-62 , already published by Arnold (1965), are repeated for completeness. Statistical analyses gave the following results.…”

“…Winter ablation is negligible in most Arctic regions. Moreover, Arnold ( 1965) who made observations throughout three summers found that summer accumulation was less than 10 mm. In these circumstances, the winter balance should be approximately equal to the total accumulation; we shall call it "total accumulation" in what follows.…”

“…In 1959, the Polar Continental Shelf Project began an investigation of one such ice cap, the Meighen Ice Cap. Arnold (1965) made meteorological observations and measurements of mass balance and flow from 1959 to 1962. The mass-balance and flow measurements have been continued; they form the subject of this paper.…”

The influence of superimposed-ice formation on the sensitivity of glacier mass balance to climate change

“…ba la nce m odel s (R eeh, 1991; O erlem ans a nd others, 1993). Superimposed ice forms at the base of the snowpack on Arctic glaciers, where percolating meltwater refreezes on contact with underlying cold ice (Baird , 1952;Arnold, 1965;Koerner, 1970;Palosuo, 1987;J onsson a nd H ansson, 1990). Ice formed in this way has to be melted again before it can run off from the glacier surface, effectively reducing the net abl ation p roduced by a given input of energy to the glacier surface.…”

A Cirque-Glacier Chronology Based on Emergent Lichens and Mosses

“…Beyond 40 m of the glacier toe the lichens disappear. The emergence of patterned ground (Smith, 1961;Swinzow, 1962;Falconer, 1966 ;Black, [ CI973] ) and of vegetation (Arnold, 1965;Lowden and Blake, 1970;Collins, 1976) from beneath glaciers is well documen ted in polar areas. Furthermore, on Baffin Island, emergent mosses have been dated at 350 ± 75 years B.P.…”