J ourna/ of G/aci%ID', Vo l. 9 , No. 56, 1970
MASS BALANCE OF THE WARD HUNT ICE RISE AND
ICE SHELF: A 10 YEAR RECORD
By G. HATTE R SL E y-SMITH and H. S E R SON
(Defence R esearch Establishment Ottawa, Ottawa 4, Onta rio, Ca nada )
ABSTRACT. 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 balan ces m easured in the
other yea rs o n both ice rise a nd ice shelf a re a ll negative.
REsuME. Bilan de masse du dome de glace de Ward H unt et de Ward H unt Ice Shelf: l a ansde resulta ts. On presente les
resulta ts d e 10 ans (1958- 68) d 'observations d e l'accumul atio n e t de l'a blation sur le d o me d e glace de W a rd
Hunt e t d e trois annees (1965- 68) sur la W a rd Hun t I ce Shelf. L e bi lan net du dom e d e glace pour les
trois a nnees 1962- 65 es t positif, ta ndis que les bi la ns nets m esures les a utres a nn ees ta nt sur le d om e que sur la
p la tefoemc d e g lace sont tous negatifs.
ZUSAMMENFASSU NC. A1assenbilan z der Ward-Hullt-EisGlifwolbung 1lI1d des Ward H unt Ice Shelf: eine I o-JahreUbersicht. Die Erge bnisse l o-j ah riger Beobachtungen ( 1958- 68 ) d er Akkumul a tion und d er Ablation a n d er
Ward-Hunt-E isa ufwolbung und 3-j a hri ger Beobachtu ngen ( 1965-68) am W a rd Hunt I ce Shelf werden
vorgel egt. Die Ne tto-Massenbilan zen d er E isaufwolbung sind fur di e 3 Jahre 1962- 65 positi v, wahrend di e
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.
INTRODU CTIO N
Since 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 Sh elf 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 amo unted 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) reco rds on the ice rise an d 3 years' ( 1965- 68) records on th e ice shelf are
analysed.
F I ELD DATA
Th e resul ts of the m easurements at 42 poles on th e ice rise a nd at 100 poles on the ice shelf
between '963 and 1969, toge ther with data from 45 poles on th e ice rise for 1959- 60, a re
shown in Tables I and H . In each tab le the ranges and the means of total a nnual accumulation
a nd of net an nual accumulation 01" ablation at the various poles are shown. For the years
247
JOURNAL
OF
GLAC I OLOGY
1960- 62 there are figures only for the combined net ablation for the 2 years, and there are no
figures for the 1965- 66 accu mu lation. The ice shelf is ch aracterized by a system of parall el
surface rid ges a nd tro ughs (Hattersley-Smith, '957 ) and in Table 11 results from ridge poles
are d istinguished from those from tro ugh poles in separate columns.
74°
3km
Ar c t ic
-- .......
.-. -----,~'~~::--:--\;
- ~-(~\ ~.-.-..':::::::.- ...-
\.....
8 3°
o
2
Ocean
_- -- -
,
"
\ '"
-- - -. _.I_ce Front
---
------_ .... _-------- .....
.. .... \
..
83°
'....
' \
07 '
..
.. .
~
Ice
'....
",
Ri se
07'
'~
ICe
Shelf
, .... .. -- ........ ....
...-.... ... .. . ' '
..
"
Fig.
I.
8
83°
OS'
Map of Ward Hunt Island and adjacent ice rise and ice shelf.
TABLE I. ACCUMULATION AND ABLATION ON THE WARD HUNT ICE RISE
Accumulation
Summer
1959
1960
19 61 }
19 62
196 3
196 4
19 6 5
19 66
19 6 7
1968
196 9
Number of
poles
45
45
Date
Net ablation! accumulation
(-)
(+)
Range
Mean
M ean
Range
Mean
M ean
mm
mm
Inm water
mm
mm
mm water
5 10
780
'73
255
Late June
Late June
- 90 to - I 010
42
42
41
42
42
42
40
38
20 June
25 June
12 June
4 1025023 0-
1 260
1 420
9 00
810
55 0
57 0
25 1
171
177
17 June
5 May
15 May
330- 660
240--1 120
260- 720
49 0
560
47 0
15 2
174
146
- 76
- 110
- 68
- 640
-57 6
+ 180
+ 160
+ 3 10
- 210
- 140
- 10
+ 1'7
+ 104
+ 202
- 137
- 91
- 7
-
- 140 to
- 270 to
+ 40 to
- 420 to
- 470 to
- 470 to
+
+
+
+
+
+
570
360
750
10
30
170
] 22
MASS
BALANCE
OF
WARD
H UN T
I CE
RI SE
AND
I CE
SHELF
In computing water equivalents from these data certain ass umptions have been made.
First, a mean d ensity of 0.3 I Mg m - 3 has been assumed for the spring snow cover , based on the
results of pit studies in 1968 and 1969. It must be rem embered , however , that the total accumula tion in any year was not m easured , sin ce no record is available of snow that fell between
Mayor June and the end of the ablation seaso n. H ence, figures for snow accumulation must
be regard ed as minima . The limited data cause an obvious discrepancy in the 1965 summ er
when the net accumulation for the ice rise exceed s th e apparent total accumulation by 25 mm
(Table I ) . Evidently, in this very cool summer there was appreciable snowfall after the middle
of June. Secondly, in computing n et accumulation which in this area takes the form of superimposed ice or very icy firn, a m ea n d ensity ofo.65 Mg m - 3 has been assumed for the material.
The same d ensity has been used for computing th e ablation of th is material as form ed after
1962 , but a density of 0.9 Mg m - 3 has been used for th e d ensity of the ice m elted from the
long-standing ablation surface tha t existed before 1963 .
TABLE
Ir.
ACCUMULAT!ON AND ABLAT I ON ON THE "V ARD HUNT I CE SH E LF
Ridge poles
J\fumber
/Jale
23 June 196 7
13 Ma y 196 8
18Ma Y l 969
T rough I'oles
JV ll m ber
A ccu m flla l i on
of
poles
Rauge
18
60
60
4 20- 740
2 70- 9 80
270- 530
AI/ean
A'/eall
mm wat e ,'
mm
537
560
440
166
174
136
of
/M/CS
3
36
38
AI/Call
m 111
Range
mm
2 10 - g 10
R a llge
111111
1966
196 7
Ig6R
18
60
Go
- 550 to - 180
- -14 0 t o - 40
- 360 to t 150
174
192
149
ablalion/acc/lmulation
(-)
(+)
Range
All ean
AI/eall
(+)
A4roll
kleall
mm
mill wat e r
- 3 10
- 279
- 2 50
- 2'25
-
A'/eall
mm w a t e r
J\I/ ean
mm
At/call
mm wa te r
540
580
460
'i D
16 7
14 3
,Net
ab/at inll /accumulat ion
(-)
5 60
6 20
4 80
480- 690
330- 1 240
N,t
S li m mer
All poles
Accumulatio1l
ACCU11I1IIa l ; o ll
100
- 90
- 22 0 to - 640
35
34
- 7 5 0to -
IIO
- 4 60 to + 250
JVel ablat ioll
mm
mm wate r
mm
A1eall
mm wa te r
- 39 0
- 340
- 35'
- 306
- 11 7
320
280
110
288
252
99
-
13 0
M roll
ANALYS IS
The d ata in Tables I a nd Il have been pl otted in F ig ure 2. Since there are no com plete
meteorologi ca l d ata for Ward Hunt Island for th e sum mers in question , temperature data
from Alert, the nearest wea ther sta tion , have been used to provide an indica tion of the
" warmth " or otherwise of the summ ers 1959- 68 . Mean temperatures at Alert for the months
of June, July and Aug ust, a nd for the whole sum mers have been p lo tted below the massbalance data.
Considering first the 10 yea rs' data from the \I\lard Hunt ice rise, we note: ( I) th e great
ra nge of snow d epths measured in the spring, varying by up to 50 % or more about a mean ,
(2) th e similarly great range in net ablation and accumu lation, including both ab lation and
accumula tion at different p oles in the sam e season . Snow d eplhs are d ep end ent on wind
ac tion and on irregu larities of the prev ious season 's a blation surface, which are comparatively
large in relation to snowdepthsof th e orderof 500 mm. At the sam e time, th e topography of th e
ice rise, a lthough subdued with an elevation nowhere exceeding 30 m , is such that poles are
situated with aspects varying from more or less northerl y to m ore or less southerly and leading
to differences in amo unts of ablation. The m a in point emerging from comparison of summer
ablation values on the ice rise with the corresponding m ean monthly temperatures at A lert is
that there is no close correlation . Admittedly, v\lard Hunt I sland is about 200 km west-northwest of Alert, so that local vari::ttions in the general weather pattern of north-eastern ElIesm ere
I sla nd may well account for the lack of correlation . But th ere are two other factors that should
be mentioned. The m ethod of calculating m ean dail y temperatures at Alert (from which the
mean month ly tem peratures are d erived ) as t (daily maximum plus daily minimum) may not
provide the best assessment of an ablation sea son , as Arnold and MacKay ( 1964) have pointed
JOURNAL
OF
GLAC I OLOGY
ou t. Nor in the present case does the use of mean d a ily maximum temperatu res at Aler t give
a ny better correlation. F u rthermore, any assessment of the ablation season based on tempera tu res alone ignores th e drastic reduction in m elting caused by a new cover of snow with its
high a lbed o. In an area where mean su mmer temperature d oes not exceed + 3°C , the small
temperature d ifference that d etermines whether precipitation falls as rain or snow is very much
200 1965 - 66
LEGEND
1966-67
1967-68
...J
::>
:::E
100
A
Sur lace
moss
balance
on
i ce
Moss
balance
Mean
and
on
Ice
temperatures
-_-_-_-_-_-1-&-'.......
rise ,
AUQust , and
ot
lar
J une ,
mean
Alert
----- ----------------
200 -_-_-_-_-_ ----------
July
:3 00 1--'=-=--=-='-1
summe r
...J
m
ex
1959 - 1968
1962 - 63
1960-62
1959-fiO
ex
o
-----------------.
r." 100 -_ -_-_-_-_....::..;9
E
E
temperatures
300 1958-59
u
0 _ _ _ _ _______ _
1958 - 1968 .
c
::>
u
s hel I,
1965- 19p8
B
5
_•• • ••• _. __ _._ •• • __ >=
ex
A
400
1963-64 1964 -65
z
o
....
200
E
...J
::>
r+;:-:+~+;:-:+:-;+~~""""-rl..l++ ++:
100
+++++
o
f
ex
. . _- . . _- -- .... + .. +
+++++
:::E
..+.+
+++++
::>
u
u
°r.-~-~-~-~-~-_~-~_~-~:~_~-_lr_=_~_~_~_-~_~-~:~_"-~_-=_1r~+~+~+~+~+~+~+-+~+~+~~+~+~+~+~+~+l=_~_~_~_~_±_~_~_~_~_~~c.~~
---------- - - - - -----
ex
z
100"'-=-='-=-':""':=--l
o
....
-•••• • - .-- ex
200
...J
--
300
-- --
m
---
B
ex
+6
.
u
+4
Q.
:::E +2
w
tZ
ex
'":::E
0
-2
c
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
SUMMER (JUNE, JULY, AUGUST)
Fig.
2.
Mass balance on the Ward Hunt Ice Shelf and ice rise, and mean summer temperatures at Alert.
ou t of proportion to the effect on ablation at an ice surface (Hattersley-Smith, 1960) . T h e
high incidence of low cloud and fog near Ward Hunt Island in su mmer (Sagar, 1962 ) is
probably a fu rther factor leading to low ablation, as has been suggested by Paterson (19 6 9)
in the case of the Meighen Ice Cap, and to d istor tion of any comparison with the weather at
Alert. Since the main purpose in this paper is to p resent rather than expla in the fig ures for
mass balance of the ice near Ward H u nt Isla nd, th e comparison with data for Alert will not
MASS
BALAN CE
OF
WARD
H UNT
I CE
RISE
A ND
I CE
SHELF
be pressed , nor is it believed for the reasons indicated above that this would be very fruitful.
It is sufficient to poin t out the correlation between more than average warm summers a nd
more than average cold summers in the two areas. Thus the relatively high net a bl ation on
the ice rise for the combined summers ' 96 1- 62 agrees with the unusually high temperatures
at Alert in the summer of ' 962; presumably most of the ablation occurred in ' 962. Again ,
the relatively high n et accumulation in 1965 agrees with the low summer temperatures at
Alert. But it is anomalous to find that there was net ablation on the ice rise in the summer of
'959 but net accumulation in the summer of ' 964, which was appreciably warm er at Alert.
For the ice-shelf grid in the 3 years 1965- 68 for which records are available, there was a
range of snow accumulation both for ridges and troughs similar to that measured on the ice
rise (Table II ) . In 1967 onl y three trough pol es were available for m easurem en t, but in 1968
and '969 the mean snow d epths in the troughs were 60 and 40 mm greater, respectively,
than on the ridges. A t the same time net a blation in the troughs was 81 and 27 mm greater
than on the r idges, with wide variations in both areas. Th e lakes that occupy the troughs
during th e abla tion season do not drai n completely, so that the net ablation m easured on the
ridges is less than the actual ablation. Nevertheless, the curren t regime, as shown from only 2
years' useful observations, is competent to preserve the ridge-and-trough topography and
even to allow slight d eepening of the troughs. It is in teresting to find approximately twice as
much net ablation on the ice shelf as on the ice rise in the two summers of ' 966-67, a lthough
in 1968, when the ice rise was essentia lly in balance, there was a deficit of about 100 kg m - 2
on the ice shelf. From the figures of net acc umulation on the ice rise in 1962- 65 (Table I ), it
seems very likely that there was also n et surface gain on the ice shelf during these 3 yea rs.
I t should be emphasized that the present data refer only to the surface mass balance of the ice
shelf; there is no information on whether melting or accretion is taking place at the underside.
CONCLUSIONS
On the ice shelf the years ' 906- 62 were a p eriod of net surface ablati on of the order of
metres of water; they were foll owed by 3 years ( , 962- 65 ) of probable positive surface regime,
and then by 3 years ( , 965- 68) of net surface ablation totalling 640 mm water (Table II ).
On the ice rise the years ' 958- 68 were a p eriod of negative mass bala nce totalling 570 mm
water, but the years , 962-68 were a period of positive mass balance totalling 190 mm water
(Table I ) . Qui te small d eviations from mean summer temperature a ppear to determine
whether the mass balance is positive or negative, and for this reason neither ice rise nor ice
shelf should be considered as a relict glacial feature.
ACKNOWLEDGEMENTS
'Ve a re grateful to Messrs D . ] . Finlayson a nd B. 'vV. Ward for assistance in the field , and
to Dr E. Dorrer for the base map (Fig. I ) . The Director, Meteorological Bra nch , D epartm ent
of Transport, Toronto, kindly provided the meteorological data from Alert.
MS. received 29 D ecember 1969
REFERE NCES
Arnold, K . C. , mId MacKay, D . K . 1964. Different methods of calcu lating mean d ai ly temperatures, their
effects on degree-day totals in the high Arctic and their significance to glaciology. Geographical Bulletin
(Ottawa ), No. 2 1, p . 123-29.
Crary, A. P . 1959. Build-up of thick floating ice in Arctic a reas. (In Bushnell , V. C., ed. Proceedings cif the second
annual Arctic planning session, October 1959. Bedford, Mass. , Geophysics R esearch Directorate, Air Force
Cambridge R esearch Center, p. 39- 42. (GRD R esearch Notes, No. 29. ))
Hattersley-Smith, G. 1957. The rolls on the Ell esmere ice shelf. Arctic, Vo!. 10, No. I , p . 32- 44.
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Hattersley-Smith, C . Ig63. T h e Ward Hunt Ice Shelf: recent changes of the ice front . Journal oJ Glaciolog)"
Vo!. 4, No. 34, p. 4 15- 24.
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[A. P. Cra ry a nd R . L. C hristie] . Arctic, Vo!. 8, No. I , p . 3- 36.
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Hattersl ey-Smith. Arctic, Vo!. 5, No. 2 , p. 67- 103.
L ister, H. 1962. Heat and mass balance at the surface of the Ward Hunt Ice Shelf, Ig60. Arctic Institute oJ North
America. R esearch Paper No . Ig.
Lotz , j. R. 196 1. Analysis of m eteorological a nd microm eteorological observations, northern E llesmere Island,
1959. Arctic I nstitute oJ North America. Research Paper No. 12.
Paterson, W. S. B. 1969. The M eighen Ice Ca p, Arctic Ca nada : accumulation , ablatio n a nd flow. Jourl/ol oJ
Glaciology, Vo!. 8, No. 54, p . 34 1- 52 .
Saga r, R. B. 1962. Meteorological and glaciological stud ies: ice rise station, Ward Hunt Island , May to September 1960. Arctic Institute oJ N orth America. Research Paper No. 24.