Antarctic Snow and Ice Studies

291 Pages·1971·6.146 MB·English

ANTARCTIC
RESEARCH
SERIES
American Geophysical
ANTARCTIC
RESEARCH
SERIES
American Geophysical
Volume 1
Biology of the Antarctic Seas
Milton O. Lee, Ed.
Volume 2
Antarctic Snow and Ice Studies
Malcolm Melior, Ed.
Volume 3
PolychaetaE rrantia of Antarctica
01ga Hartman
Antarctic Snow
and Ice
ANTARCTIC
Volume 2 RESEARCH
SERIES
Antarctic Snow
and Ice Studies
Malcolm Melior, Editor
Published with the aid o[ a grant [rom the National ScienceF oundation
PUBLISHER
AMERICAN GEOPHYSICAL UNION
OF THE
National Academy of Sciences-(cid:127)National Research Council
Publication No. 1197
ANTARCTIC
Yolume 2 RESEARCH
SERIES
ANTARCTIC SNOW AND ICE STUDIES
Malcolm Mellor, Editor
Copyright @ 1964 by the American GeophysicalU nion
Suite 506, 1145 19th Street, N. W.
Washington, D.C. 20036
Library of CongressC atalogue Card No. 64-60078
List Price, $12.00
Printed by
The William Byrd Press, Inc.
Richmond,
THE ANTARCTIC RESEARCH SERIES
During the International Geophysical Year discussionsw ere held among geo-
physicists,b iologists,g eologists,a nd others--discussionsa imed at developinga
medium for the publication of the papers resulting from the intensive research
work being done in Antarctica. The Antarctic Research Series is designedt o pro-
vide (cid:127)his medium, presentinga uthoritative work with uniformly high scientific
and editorial standards from leading scientistse ngagedi n Antarctic research.
In a senset he series continues a tradition dating from the earliest days of
geographice xplorationa nd scientifice xpeditions--the tradition of the expedition-
ary volumes which se(cid:127) forth in rich detail everything (cid:127)ha(cid:127) was seen and studied.
Bu(cid:127) in much of (cid:127)he presen(cid:127) Antarctic work one expedition blends into the next,
and i(cid:127) is no longers cientificallym eaningfult o separate(cid:127)h em. However, Antarctic
researchi n all disciplinesh as a large degreeo f coherencea nd deserves(cid:127)h e modern
coun(cid:127)erpar(cid:127) (cid:127)o the expeditionaryv olumeso f pas(cid:127) decadesa nd centuries.
Papers appearing in (cid:127)he series represent original contributions (cid:127)oo lengthy or
o(cid:127)herwise unsuitablef or publica6on in the standards cientificj ournals.T he mate-
rial publishedi s directedn ot only (cid:127)o scientistsa ctively engagedi n (cid:127)he work bu(cid:127)
to graduate studentsa nd scientistsi n closelyr elated fields as well. The seriesw ill
serve as a source of information bo(cid:127)h for the specialis(cid:127) and for the layman versed
in the biological and physical sciencesM. any of (cid:127)he early volumes will be cohe-
sive collectionso f researchp apers groupeda round a central (cid:127)heme. An editor for
each book is drawn from the discipline it represents,a s are the reviewers on
whom each editor relies.
Early in 1963 the National ScienceF oundation made a grant to the American
GeophysicalU nion to initiate the series,a nd a Board of AssociateE ditors was
appointed to crystallize and implement it. To represent the broad nature of the
series,t he memberso f the Board were chosenf rom all fields of Antarctic research.
They include Jarvis Hadley, representingg eologya nd solid Earth geophysics;
Harry W. Wells, aeronomy and geomagnetism;A . P. Crary, seismologya nd
glaciology; George A. Llano, botany and zoology; Waldo L. Schmitt, marine
biology and oceanography;a nd Morton J. Rubin, meteorology.A GU staff mem-
bers contributing to the Series include Carol E. Cameron, managing editor, and
Marie L. Webher, style editor.
Haaa¾ W. W(cid:127)s
Chairman, Board o[ AssociateE ditors
Antarctic Research
CONTENTS
Introduction to the Antarctic Research Series
Harry W. Wells .................. vii
Preface
Malcohn Melior .................... ix
GlaciologicalS tudiesa t Wilkes Station,B udd Coast,A nt(cid:127)arctica
Richard Leo Cameron ................. 1
GlaciologicalS tudiesi n West Antarctica, 1960-1962
Hiromu Shimizu ................... 37
Horizontal Strain and Absolute Movement(cid:127) of the Ross Ice Shelf between
RossI sland and RooseveltI sland, Antarctica, 1958-1963
James H. Zumberge ................. 65
The RossI ce Shelf Survey (RISS) 1962-1963
W. Hofmann, E. Dorrer, and K. Nottarp ........... 83
SnowA ccumulationo n the RossI ce Shelf,A ntarctica
John A. Heap and Arthur S. Rundle ............. 119
The Drainage Systemso f Antarctica: Accumulation
Mario B. Giovinetto .................. 127
Densification of Snow in Antarctica
Kenji Kojima ..................... 157
Firn StratigraphSy tudieso n the Byrd-WhitmoreM ountainsT raverse,
1962-1963
R. M. Koerner .................... 219
StructuralG laciologyo f an Ice Layer in a Firn Fold, Antarctica
John R. Reid, Jr ................... 237
Distributiono f ParticulateM atter in a Firn Core from Eights
Station, Antarctica
Lawrence D. Taylor and James Gliozzi ............
Antarctic Research Series Antarctic Snow and Ice Studies Vol. 2
PREFACE
Glaciology, now broadly defined as the study of ice in all fornis, is often regarded
as a somewhat esoteric subject, though it takes little thought to dispel the notion.
The sheer quantity of ice on Earth, together with its past anti present effects on
geophysical processes and human activity, colnmands attention, while at tlie same
time ice itself proves to be an ideal material for studying processes and propertie?
that involve almost the entire field of classical physics. With the belated wedding
of academic icc pliysics and glacier study, glaciology is contributing significantly
to geophysics and materials science, as is evidenced by continued support for
research both in the laboratory and in the field.
Some 90 per cent of the world's ice is contained in tlie Antarctic ice sheet, a
glacier of continental proportions about which little was known prior to the Inter-
national Geophysical Year. Since 1957 the United States, by maintaining through
the National Science Foundation a vigorous Antarctic glaciological program, has
made an impressive contribution of knowledge which is reflected in part by the
papers and references in this volume. By entering heartily into the spirit of inter-
national cooperation that has so brightened recent Antarctic endeavors, the U. S.
has made a further contribution: to human understanding and to the diffusion of
knowledge. This too is reflected here, for more than half of the authors came into
the program from foreign countries. Much has been learned, but more remains to
be studied, since, as research should, the investigations have raised new questions
as fast as old ones were answered. Before efforts are renewed in force, however,
there should be some assessment of the broad problems and of the methods avail-
able for their solution; in this respect the following collection of papers should
be helpful.
In the beginning, the magnitude of the problem-ab initio investigation of a
continent-called for a broad and simple approach. At the same time, the severity
of the environment imposed limitations on the sophistication of techniques and
equipment. With huge areas still to be penetrated by ground parties, the broad-
brush treatment must continue for some years, but already a trend of refinement
can be discerned in the wake of pioneering studies. We note, for example, the
adoption of precise survey methods, the use of new geochemical techniques, in-
troduction of modern concepts in mechanics, and a slow improvement in sta-
tistical data interpretations. On the other hand, there are some shortcomings: a
number of outstanding problems must be cleared up to open the way for progress,
and certain techniques are due for overhaul. There is a need for more control
studies, for example in the realm of stratigraphy, so that knowledge gained from
theory and experiment can be applied to the complexities of field situations.
Some long-standing procedures, such as the apparently straightforward stake
measurement, niust be re-examined and revised so that newcomers to the field
are spared the frustrating cycle of error and rediscovery. There is no call for
gloom, though; excellent new projects can be planned as long as the results and
experiences of earlier workers are carefully considered.
Too often the consideration of earlier work has been made unduly difficult
because publication was long delayed or because results were immured in obscure
and unobtainable reports. Such situations demonstrate the folly of spending
vast sums to launch scientific expeditions while leaving publication to chance;
Copyright American Geophysical Union
Antarctic Research Series Antarctic Snow and Ice Studies Vol. 2
unlcss knowledge is con~nlunicateci,t lie effort expended in winning it is utterly
wastcd. The National Science Foundation is therefore to be congratulated for
sponqoring the Antarctic Research Series, whicli makes it possible for authors to
present and discuss their data in more detail than would be possible in the
journals and wliicll at the same time provides readers with compact and readily
obtainable reference sources. Altliougli publication is one of tlie less spectacular
ways to spend rescarcli funds, none is inore valuable, for tliought conles before
ironmongery on the road to knowledge.
~/IALCOLM NIELLOR
Copyright American Geophysical Union
Antarctic Research Series Antarctic Snow and Ice Studies Vol. 2
GLACIOLOGICAL STUDIES AT WILKES STATION,
BUDD COAST, ANTARCTICA
RICHARD LEO CAMERON
Institute o(cid:127) Polar Studies, Ohio State University, Columbus
Abstract. Glaciological studies were conducted in the vicinity of Wilkes station, on the
Windmill Islands, Budd Coast, East Antarctica, from February 1957 to January 1958. The
main aim of this work was to determine the mass balance of the margin of the ice sheet,
because the state of this ice reflects the condition of the entire ice sheet. The environment
of the marginal ice was determined utilizing three meteorological stations: a main base at
sea level; S-1, 5 kilometers inland, at 262-meter elevation; and S-2, 80 kilometers inland, at
1166-meter elevation. The ice sheet inland of Wilkes station receives little precipitation from
cyclones, and there is little snow accumulation. Stake and shallow-pit studies of snow accumu-
lation give values ranging from 7.9 to 15.9 gcm -2 per year. Studies in a deep pit at S-2 give
an annual mean accumulation of 13.3 gcm -(cid:127)for the last 174 years. Between S-1 and S-2 there
is no pronounced variation in accumulation due to elevation or distance from the coast.
Studies of 10-meter temperature from the coast to 96 kilometers inland give a lapse rate of
1.02øC per 100-meter elevation. From 10- to 62-meter depth at S-2 there is no discernible
temperature gradient. Temperature gradients in the 10- to 28-meter depth interval from S-2
to S-1 are positive and reach nu2.8øCp er 100 meters at S-1. Temperature studies at S-1 give
the following values of thermal diffusivity and thermal conductivity for ice of density of
0.87 g cm-3:
a = (15.38 q- 0.9) X 10- 3 cmaec -(cid:127)
k = (6.56 q- 0.4) X 10- 3 cal sec- (cid:127) cm- (cid:127) øC- (cid:127)
These values are considerably higher than those for pure ice of density of 0.917 gcm -s, but
this difference is not as yet explained. The Vanderford glacier, south of the Windmill Islands,
is moving 2.1 meters per day and is discharging 3.86 km 3 of ice per year. Total ice discharge
along 167 km of Budd Coast is 5.43 km 3 of ice per year, equivalent to 4.9 km (cid:127) of water. Strain
studies of the ice-sheet surface at S-2 give a compressire strain rate downslope of --24 X 10-5
year -* and an extensive strain perpendicular to the slope of +35 X 10- 5 year -(cid:127). Calculation of
the regime of the ice-sheet margin, an area of 9400 km -ø,i ndicates an excesso f ablation over
accumulation of 0.16 km (cid:127) of water per year. The ice sheet in the Budd Coast area is thinning,
a condition consistent with glacial geology observations on the Windmill Islands.
INTRODUCTION the Antarctic ice sheet abutting them, lie along the
eastern edge of VincennesB ay; they consisto f 75
This report concernst he glaciologyo f the periphery
krna of exposedb edrock dispersedo ver an area of
of the Antarctic ice sheet in the vicinity of Wilkes
450 kma. Some are true islands, but others are con-
station. Wilkes station, which is situated on the
nected to the ice sheet by ice ramps.
Budd Coast at Clark Peninsula in the northern part
The ice abuts the islands on the east, and the
of the Windmill Islands, latitude 66ø15.4'S, longi-
relatively thin ice is producing a shear moraine or
tude l10ø31.5'E (see Figure 1), was operated by
a Thule-Baflin type moraine, as defined by Weert-
the United States from February 1957 to January
man [1961], at about 120-meter elevation. The
1959 as part of the International Geophysical Year
profile of the ice sheet inland for 80 km to l166-
Antarctic program.
meter elevation is parabolic. There are no crevasses
The topographically low Windmill Islands, with
along this line, and there are no known nunataks
inland of the Wilkes area.
(cid:127) Contribution 48, Institute of Polar Studies, Ohio State
University. To the south of the islands the Vanderford gla-
Copyright American Geophysical Union