Jou rnal uIClaciology, \ '0 1. 6. No. 47. 19G7
CORRESPO
DENCE
The Editor,
J ournal oJ G!aciology
S IR,
About the use oJ the eX/Jression "inland ice"
In much rece nt glaciological literature th e D a ni sh word f ndlandsisen, a nd its equivalents the Inland l ee
(English ) and l'Indlandsis (French ) have ca used some confusio n. These express ions h ave been used as
sy non ymous with " ice sh eet" or " ice cover " , as well as in a more restri cted way to m ean the G reenl a nd
I ce Shee t. It mig h t ther efore b e of interest to clarify the origin of the word Indlandsisen, from which th e
term s the Inland I ce and " l'Indlandsis" a re presum a bl y d erived.
It is significant that the express ion "the Inla nd I ce" is genera ll y used w ith the d efinite a rticl e, just
as in th e Danish word Indlandsisen (-en bein g the d efiniti ve form ) . This a lone implies that in both
languages the term d enotes a specific ice m ass a nd is not m erel y d escriptive .
Concerning th e origin of the word fndla ndsisen the Danish geologist K . J . V. Steenstrup ( 1900,
p. 278) wrote "Concerning the origin of thi s na m e, Dr. Rink has informed m e that h e on his re turn from
Greenl a nd in 1851 was not sure what h e sho uld call th e genera l ice cover of th e co untry, until th en
ca lled the I ce Blink (lsblinken ), to distinguish it from th e ice cover of the p eninsulas and islands, a nd
wh en h e on that occasion asked Forchhammer a ndJap. Steenstrup for advi ce, the las t named sugges ted
to him the name of lndlandsisen" (translated from Danish by th e prese nt writer) .
Of the individuals m ention ed b y K. J. V. Stee nstrup, H. Rink ( 18 19- 1893 ) was th e first to draw
a ttention to the Inland I ce and the problem s concerning its production of calf ice a nd its origin (K ayser,
1928, p. 367; Oldendow, 1955) . J. G . Forchhammer ( 1794- 1865) was professor of min era logy at
Copenhagen U niversity from 183 1 a nd J apetus Steenstrup ( 181 3- 1897 ) professor of zoology at th e sa m e
university from 1845. K . J. V. Steenstrup ( 1842- I 913 ) who is quoted a bove a nd w ho was a nephew
of J apetus Steenstrup, made ex tensive in vest igations of the west coast of G ree nl a nd between 187 [ a nd
1899.
There is no doubt that th e word fndlandsisen origin a ll y m eant a n ice cover , barred from th e sea by a
generally wid e coastal land strip and , in contrast to normal g laciers, of a n immense ex tent and with a
base situated at sea-level. Furthermore, from its origin , it is clear that the na m e is res tricted to such an
ice cover in Greenland. "The Inla nd I ce" or lndlandsisen should th erefor e be emph as ized as a place n a m e
rath er than as a d escriptive term for an ice shee t ; just as th e Sahara is th e g rea t Libyan d esert a nd not
a sy nonym for "desert", lndlalldsisen is th e great Greenl a nd I ce Shee t a nd not a sy nonym for " ice shee t".
To ta lk a bout "th e A ntarcti c Inland I ce" o r worse, " the Pl eistoce ne Sca ndin av ia n Inla nd I ce" is
therefore not correct. It is proposed that in future th e word I ndlandsisen o r th e Engl ish equi val en t "the
In land I ce" is r estri cted to its original m eaning: th e ice sheet of Gree nl an d , an d that the gener a l expression for extensive ice covers elsew here or at ot her tim es shou ld be " ice shee t" o r "ice cover" .
Gronlands Geologiske Undersogelse,
0 stervoldgade 5- 7,
Kobenhavn K , D enmark
28 D ecember 1966
ANK E R WEIDI CK
REFERE NC ES
Garboe, A.
Kayser, O.
O ldendow,
Steenstrup,
Ig6 1. Ceotogiells hislm"ie i Danmark. Vo!. 2. K 0benhavn , C. A. Rcilze!'
Ig2B. The Inl and Ice. (111 Creentalld. Copenhagen, C. A. Reilzel, Vo!. I, p. 35 7- 422.)
K . Ig55. Gmnhendervenn en Hinri ch Rink. Del Crolllalldske Selskabs Skrifter, lB.
K . J. V. Igoo. Beretning om en unders0gelsesrej se til 0en Disko i som meren IBgB. Meeldelelse .. om
CrOniallel, Bd . 24, Nr. 3.
SIR,
Walsh Glacier surge, I966 observations
\Va lsh G lacier (Canada a nd Al aska ) was observed m a king a rem a rkab le surge between 196 1 and
1965, a m ax imum mov em ent of a bout 10,050 m. occurring durin g th a t interval (Pos t, 1966) . Obli qu e
76 3
JOURNAL
OF
GLACIOLOGY
aerial photographs of the glacier taken in 1966 show that the surge has continued, the greatest changes
being recorded in the terminal region. A maximum movement of about 4,000 m . occurred in the
narrow, lower part of the Walsh Valley between 23 August 1965 and 17 September 1966. The inAux of
Walsh Glacier ice has compl etely transformed Logan G lac ier b elow the point where Walsh G lacier
joins. Virtually stagnant ice, largely derived from Logan Glacier, is now completely in vaded and acti vated by ice from W a lsh G lacier, and the terminus of Logan G lacier has been th rust ahead as much as
1,500 m. (Fig. I ) .
Fig.
Walsh Glacier (lift) and Logan Glacier (center ), 17 September 1966. The surge of Walsh Glacier, which in August 1963
hadjust reached the point where the glaciers join, has now completely dominated lower Logan Glacier. Formerly, ice below the
junction was virtually stagnant and the positions of the medial moraines indicated that Walsh Glacier hadfurnished only about
one-quarter of the ice in the lower vallq. The stagnant, moraine-covered ice in the foreground, now being over-ridden by the
advancing ice from Walsh Glacier, is a part rifChitina Glacier whichjlows infrom the lower lift. (Photograph by Austin
Post, U.S. Geological Survey )
J.
COR RE S PONDENCE
I ce movem ent farther up Walsh Glaci er has been much less than in the lower valley during th e past
year. In the vicinity of the first tributa ry (Post, 1966, fig. I , tabl e I ) surface features were displaced
down-vall ey a bout 2,100 m. ; n ear Cadorna G lacier the movem e nt was approximately 1,500 m. The
redu ced rate of flow in th e upper part of th e va lley is conside red ev ide nce that th e surge is about over.
This surge is unusual both in th e maximum movem ent record ed (about 11 ,500 m .) and in the p eriod
of tim e during which th e su rge has been in progress (more than 4 years) . The form er position of the
Logan G lacier m edial moraines indicates that no form er surge of Walsh G lacier of this magnitud e has
occu rred in th e past lOO years or more.
Inc reased act ivity of at least three other g laci ers in th e vicinity of Walsh Glacier in 1966 m ay b e
ev id ence o f new surges d eveloping. These a re : ( I) Baldwin Glacie r ; (2) the first tributary of Logan
Glaci e r east of Bald w in Glaci er ; (3) the next va ll ey g lacier west of Bald win G lacier. The last-mentioned
g lacier had started to advan ce sli g h tly in 1966 . The re was a lso ev ide nce (in the fo rm of in creased margina l
crevassing ) that th e la rge And erson G lac ier , th e m ajor source of ice for C hilina G lacier , is now moving
more rapid ly than in 1960. U nstab le conditions in the Ch itina G lacier sys tem , simila r to those of
Muldrow G lacier prior to its surge (Post, 1960), a nd Steele G lacie r, w hi ch surged in 1965- 66, suggest
th a t a large-scale glacier surge m ay occur in th ese g laciers in th e next few years.
U.S. Geological Survey,
T acoma, Washington, U.S .A.
I
A USTIN P OST
November 1966
R EFE RENCES
Post , A. S. 1960. T he except ional ad va nces of th e :Vluldrow, Blac k R ap ids, a nd Susitna Glaciers. Jo u.rnaL of
Ceo#ysicaL R esearch. Vol. 65, l\o. 11 , p. 3703- 12.
Pos t, A. S. 1966. The recent surge of W alsh Glac ier. Yukon and Alaska. J Ollrnal of Glaciology, Vo!. 6, No. 45,
P· 375- 8 ..
Jvl eaSllremeni oJ the jJermiUivity oJ ice
S. E va ns w rites in hi s very inte res ting publica tion (E van s, 1965, p. 785) : " W e have shown th at pure
ice h as a relaxation sp ectrum , related to te mpera ture, but more m eas urem e nts a re need ed on natu ra ll y
occurring snow a nd ice. It may th en be poss ibl e to d evelop a techniqu e for temperature m eas urem en t
in d eep ice by in ves ti ga ting the r elaxation sp ec trum with electrod es on th e sur face." For su ch a techniqu e
it is im po rta nt to m eas ure the p e rmittivity* of d eep ice layers und er th e origina l conditions of te mpe ra tu re, pressure and gra in st ructure . This co uld b e don e by m eans o f elec tro-th e rma l d ee p drillin g. I want
to sugges t a simple d ev ice for ac hi ev ing th is.
The fl a t or pyra mid a ll y pointed botto m of th e d eep -dri lling probe (Philberth , 1966) is one electrode,
th e cylindri cal sid e wall of the probe is th e ea rthed electrod e; bot h elec trod es toge ther form a capacitor.
Its capacitance can be m eas ured as fo ll ows : A ca pacito r C of hig h precision is connec ted parallel to it
(in o rder to redu ce th e loss tange nt) a nd by m ea ns of a transistor- a mp li fi er A a uto-oscillation is caused ;
this is brought a bout by para ll el co nn ec ti o n of an in ductor L , o r by o ne of the kn own RC-circuits.
The f" equ ency of th e oscill ation i a fun c tion of the real part of th e compl ex permitti vity; the
ITaximum sensiti vity of th e rea l part to changes of temperature is in th e ra nge wh e re the imagina ry part
(loss fa c tor) reaches its maximum. For ice tem pera tures between - 20°C. a nd o°C., thi s ra nge is reali zed
for frequ en cies in the order of 3 kHz . For Gree nland condition s frequ encies of the order of 3 to 10kHz.
* Permitti vity is the term recommended by th e Commission on Symbols, Units and No mencla ture of the
In tern a tional Union of Pure and App li ed Physics for the quantity sometimes kn own as dielectric constant. As
the quantity is not a constant but var ies with frequ ency a nd temperature- in the case of ice the relative permittivity
can be a nywhere between 3 and loo- a term whi ch does not use th e word constant is to be welcomed. Eel.