bluuebunny/crossref_metadata_2025 huggingface dataset:
Etching Technique to Study Plastic Deformation of Ice
Authors: Krausz A. S.
Published: September 2017

When ice is kept in saturated air, thermal etching occurs. This has been applied in the study of grain boundary migration, sub-boundary and slip line formation. A few of the interesting results are reported to illustrate the usefulness of the method.
The Bara Shigri Glacier, Kangra District, East Punjab, India
Authors: Dutt G. N.
Published: September 2017

During the monsoon of 1956 the Geological Survey of India sponsored an expedition to the Bara Shigri Glacier (lat. 32° 16′N., long. 77° 40′E), Kangra District, in the great Himalayan ranges of the Punjab, as part of the Indian programme for the International Geophysical Year 1956–57. Topographical maps of the terminal 3 miles of the glacier, on scales of 1:63.360 and 1:10,000, were prepared for comparison of morphological changes since it was last surveyed 50 years ago. The glacier appears to have shrunk considerably but its full extent could not be assessed because of insufficient earlier data. The Shigri Stream now emerges from a different part of the glacier snout. In order to assist future surveys three photographic stations were established.
Formation of “Blue” Glacier Ice by Horizontal Compressive Forces
Authors: Crary A. P. , Charles R. Wilson
Published: September 2017

Data are supplied to show that the “blue” surface ice zone encountered in the Skelton Glacier, Antarctica, results from horizontal compressive forces. Examples of the densification of surface snows of the Ross Ice Shelf by this means are also given. Such density changes should be expected in any area where either of the principal horizontal strain-rates is negative.
On Melting of Fresh-Water Ice In Sea-Water
Authors: Loewe F.
Published: September 2017

Melting at the bottom of floating ice shelves may represent an important item in the mass economy of ice sheets. Some earlier studies of the behaviour of fresh-water ice in sea-water at a temperature below 0° C. are quoted.
Glaciological Observations in Trinity Peninsula, Graham Land, Antarctica
Authors: Koerner R. M.
Published: September 2017

This paper is a summary of the more important results of glaciological investigations carried out in Trinity Peninsula, Graham Land during 1958–60, and which will be published at length in Falkland Islands Dependencies Survey Scientific Report No. 42. The budgets for Depot Glacier and the ice piedmont between Hope Bay and Trepassey Bay are given and it is concluded that in a normal year they are in a state of near equilibrium. The state of the glaciers of southern Trinity Peninsula is discussed in a consideration of the importance of rime ice formation on the west coast of the peninsula. Movement and accumulation studies in Trinity Peninsula and the islands of the James Ross Island group demonstrate a decrease in glacierization south-eastwards from the central plateau area. The recent glacial history of the area is also briefly reviewed.
Measurements of Side-slip at Austerdalsbreen, 1959
Authors: Glen J. W. , Lewis W. V.
Published: September 2017

Measurements have been made using two different methods of the rate at which the glacier Austerdalsbreen is slipping past its side wall at four sites. The rate of slipping varies from site to site in a way which seems to be connected with the details of glacier flow in the neighbourhood, and in all cases is less than the slip previously measured further up-glacier at the foot of one of the ice falls, and is also a smaller fraction (about one sixth) of the flow rate in the centre of the glacier. One of the methods measured the velocity of the last metre of ice, and this method gave movements which were more erratic than the other method, which measured velocity a few metres from the edge. This suggests that protuberances of rock and boulders lodged between the ice and the rock wall cause local variations in flow which are smoothed out in a few metres. The results are discussed in connection with the process of glacial erosion.
Contribution to the Movement and the form of Ice Sheets in the Arctic and Antarctic
Authors: Haefeli R.
Published: September 2017

Starting from Glen’s flow law for ice and from a series of assumptions based in part on observations in Greenland and in the Jungfraujoch, the velocity distribution (horizontal velocity component) and surface configuration is derived for a strip-shaped ice sheet in a stationary state. For the choice n = 3 − 4 of the exponent in the power-law flow relation, there is extensive agreement between the theoretically calculated surface profile and the east-west profile measured through “Station Centrale” by Expéditions Polaires Françaises. The corresponding theoretical solution for a circular ice sheet is also given. As a first application of this theory, an attempt is made to calculate the average rate of accumulation in Antarctica from its surface profile (assumed circular in plan) and from the flow-law parameters derived from the Greenland Ice Sheet. It is also shown that a change in accumulation has only a small influence on the total ice thickness of an ice sheet. A method of calculating approximately the age of ice in an ice sheet, based on the foregoing theory, is illustrated by applying it to the Greenland Ice Sheet. After comparing the present theory with that of Nye, a general expression for the surface profile of an ice sheet with constant accumulation is set up and discussed by means of comparison with two profiles through Antarctica.
Early Discoverers XIII: The First Glaciologists in Central Asia
Authors: Kick W.
Published: September 2017

Contributions to the glaciology of the Himalaya, Karakoram, and Turkestan areas are contained in the hitherto unpublished records of the Schlagintweit brothers. These should be of considerable value for future research since the records include paintings, sketch maps, descriptions, and also measurements of glacier speed, which give details of the state of the glaciers in 1855–56. These records were used recently to great advantage on Nanga Parbat.
Notes on the Recent Advance and Retreat of Sefströmbreen in Ekmanfjorden, Vestspitsbergen
Authors: Dineley D.L. , Waters R.S.
Published: September 2017

These notes are based on observations made in 1958 while the writers were members of the Birmingham and Exeter Universities Spitsbergen Expedition. The position of the ice front in 1958 is compared with that recorded on five previous occasions between 1882 and 1936. A rapid 6 km. advance at the end of the nineteenth century has been followed by a slower but equally extensive retreat. A revision of the limit of maximum advance is based on geomorphological evidence. Reasons are suggested for the relatively small changes in the outline of the ice front since 1927, and the effects of spells of moderately high atmospheric pressure are noted.
Crystal Growth and the Formation of Spikes in the Surface of Supercooled Water
Authors: Hallett J.
Published: September 2017

Observations made of ice crystals growing on the surface of supercooled water show that they take the form of a composite structure, called surface needles, each of which consists of dendrites growing into the liquid, and of ribs growing in the liquid surface. Each needle is a single crystal. The precise form of the needle is determined by the orientation of the initial nucleus. If its optic axis is near normal to the surface, growth occurs rapidly in two dimensions and covers a much larger proportion of the surface than is covered by the narrow surface needles, so that ice forming this way appears to have its optic axis vertical. Hollow ice spikes observed on pools are shown to have been formed by the freezing of water forced from beneath the surface at the intersection of two or three surface needles, the shape of the spike depending on their orientation.
An Historical Survey of the Late-Season Snow-Bed in Tuckerman, Ravine, Mount Washington, U.S.A.
Authors: Havens James M.
Published: September 2017

As a result of an historical sketch of scientific activity on Mount Washington, New Hampshire, it is shown that the late-season snow-bed that annually forms in Tuckerman Ravine disappeared, on the average, during the first week in August for the period 1922–58 as compared with an average date of 11 August for the period 1878–1906. This appears to correspond to a rise in spring (April to May) and summer (June to September) mean temperatures of 0.9° F. (0.5° C.) for each season from 1872–87 to 1933–58. The snow-bed probably has persisted through only one ablation season during recent years, that of 1926, although some evidence exists that it may have lasted through an occasional summer during the early and middle nineteenth century.
Ogives of the Forbes Type on Alpine Glaciers and a Study of their Origins
Authors: Fisher Joel E.
Published: September 2017

Ogives form beneath active ice falls whose heads are situated near or below the firn line. They consist of curved bands of alternating white, bubbly, less dense ice and darker, denser ice with fewer bubbles, extending throughout the thickness of the glacier. The difference in character is held to be due to the different conditions in the upper ice fall, through which the ice passes in one year at high speed. In summer the thin and shattered ice is exposed to high temperatures and melt water, while in winter the conditions are of Arctic-type throughout the thickness of the attenuated ice. A lane of ice on the Gornergletscher, originating as cold, dry snow with no melt water present, illustrates the character and origin of the white bubbly ice. The greater elevation of this cold-snow ice and the waves formed beneath the ice falls are considered to be the result of the lesser thermal conductivity and greater albedo of the white bubbly ice.
Contribution to the Knowledge of the Antarctic Ice Sheet: A Synthesis of Glaciological Measurements in Terre Adélie
Authors: Lorius C.
Published: September 2017

This paper is a synthesis of glaciological investigations conducted in Terre Adélie, mainly during the LG.Y. The surface and bedrock profiles have been obtained along a 500 km. line roughly perpendicular to the coast; the mean annual temperature has been studied as a finnction of altitude, and mean accumulation has been related to distance from the coast and surface slope. Stratigraphic studies made at Station Charcot again raise the problem of the determination of mean accumulation in certain parts of the Antarctic plateau; they provide a quadratic relationship between density and depth. The snow-drift studies lead to the Mowing conclusions: wind velocity and density of drifting snow are functions of height above the surface, and the total transport depends on wind velocity. Lastly, measurements have been made of glacier flow near the coast. The paper ends with a schematic study of the mass balance in Terre Adélie; accumulation seems to be slightly larger than ablation, a result that is to be contrasted with the obtervrd coastal retreat near Dumont d’Urille base.
Deep Drilling at Base Roi Baudouin, Dronning Maud Land, Antarctica
Authors: Tongiorgi E. , Picciotto E. , Breuck W. de , Norling T. , Giot J. , Pantanetti F.
Published: September 2017

A drilling operation and core investigations at Base Roi. Baudouin (lat. 70° 25′ 5″ S., long. 24° 18′ 38″ E.) in January 1961 are discussed. The drilling, undertaken with light equipment, attained a depth of 115.72 m. From the start serious difficulties were encountered so that it was decided to use a SIPRE auger driven by the mechanism of the drilling machine. Core recovery was close to 100 per cent. Below a depth of 43.70 m., since the drill had reached the zone of high ice density (0.85 g./cm.3), a 3 m. double core barrel was used with air circulation. A depth of 79.33 m. was reached with a core yield close to 100 per cent. From this level downwards to the final depth of 115.72 in. the core yield was only 55 per cent.

Preliminary observations were made at the site. A stratigraphie profile of the first 43 m. showed an al terna-ion of coarse-grained summer layers with ice formation and fine-grained winter deposits. From the seasonal alternations of the last six years, an average annual accumulation of 38.3 cm. of water was calculated. No coloured or dust layers were observed. Between 9 and 16 m. and between 41 and 44 m. an intense formation of ice was noticed. The depth-density curve is similar to those found by the. Norwegian-British-Swedish Antarctic Expedition at Maudheim and by the Americans at Little America V. If an average annual accumulation of 38 cm. of water is assumed, the whole depth drilled corresponds to approximately 240 yr. Temperature measurements could not he carried out b;rcause of the limited time available.

Detailed stratigraphie and morphological studies of the cores, which are stored at −15°C. in Brussels, are planned, as well as chemical and isotopic investigations.
The Settling of Firn at Little America III, Antarctica, 1940–58
Authors: Hoinkes Herfried C.
Published: September 2017

Observations in the glaciological pit of Little America III (1939–41), carried out in March 1957 and in January 1958, are discussed. Of particular interest is the analysis of the settling of firn over a period of 17.6 years. The observed data, including those of Wade taken in 1940 and of Howard in 1947, were fitted best by a logarithmic expression, which proved useful as an interpolation formula. From the computed values of the rate of settling, and the observed density-depth relation, the average accumulation is calculated, using Sorge’s law. For the undisturbed period 1947–58 an average annual accumulation of 19 g./cm.2 is found for Little America III (position in 1958 about lat. 78° 26′ S., long. 163° 52′ W.).
Aspects of the Glaciology of Meighen Island, Northwest Territories, Canada
Authors: Arnold K. C.
Published: September 2017

Meighen Island lies in the centre of the north coast of the Queen Elizabeth Islands and fronts on the Arctic Ocean. An ice cap of about 76 km.2 covers about one-tenth of the island. Its greatest thickness of 150 m. occurs under the summit, near the south end, which was 268 m. above sea-level in 1960. The northern half of the ice cap is less than 30 m. thick; and the total volume is of the order of 2,000 × 106 m.3.

Precipitation is low in the northern Queen Elizabeth Islands, and Meighen Island lies in an area where summer temperatures are lowest. In the winters of 1959–60, 1960–61 and 1961–62, the snow accumulation was 12.6, 18.2 and 14.1 cm. of water equivalent. Some snowfall remained on the higher part of the ice cap in the cold summer of 1961; but the ice cap diminished in volume in each year; by 36 × 106, 72 × 106, 22 × 106 and 91 × 106 m.3 in the 1959, 1960, 1961 and 1962 ablation seasons.

If the conditions of these four seasons were maintained the ice cap would disappear in about 100 yr. However, a radio-carbon dating of a saxifrage exposed by the retreat of the ice from a small nunatak near the northern edge gave a date of less than 100 yr., and it appears that the existence of the ice cap might be sensitively related to recent climatic change.

Careful surveys were made in 1959, 1960 and 1961 in an attempt to detect movement in the ice cap. Unequivocal evidence is not available from these surveys; but the stake network has been maintained and another survey has recently been completed.
Densification of Snow on the Ice Sheet of Ellsworth Land and the Southern Antarctic Peninsula
Authors: Behrendt John C.
Published: September 2017

Density-depth curves constructed from seismic travel-time data observed at 25 locations, show a large variation over an essentially isothermal area (T = −22±2.6° C). This is correlated with the wide range of mean annual accumulation values. (A = 20 to 50g./cm.2yr). Quantitative estimates of mean annual accumulation can be obtained from seismic refraction data in this area by the expression A = 23.5+0.049(3500−V200) where V200 is the compressional wave velocity (m./sec.) observed at 200 m. from the shot point. The density-depth curves can be used to give estimates of accumulation by the expression:

where ρ40 is the density (g./cm.3) at 40 m. depth. The internal consistency of these methods is indicated by the standard deviation of ±2.9./cm.2 yr. for comparisons of accumulation estimates. The theoretical basis for these results is discussed.
On the Accumulation and Seasonal Stratification Of Snow at the South Pole
Authors: Gow Anthony J.
Published: September 2017

The seasonal distribution of snow at the South Pole and its relationship to stratigraphy was investigated to pits dug beside a number of four-year-old accumulation stakes. Results show that conventional stratigraphic methods yield thoroughly reliable values of accumulation rates. Even hiatuses in accumulation can be identified from the intensity of sublimation of layers of depth hoar in the stratigraphic section. Such hiatuses are due almost invariably to the prolonged absence of accumulation rather than to widespread scouring of pre-existing layers of snow. The bulk of the year’s accumulation is deposited as dunes during winter. The majority of dunes are subsequently transformed into linear sastrugi by wind with the result that the amplitude of surface relief observed at the end of winter frequently exceeds the average thickness of snow accumulated annually. Such gross relief does not persist to the end of summer, however. Instead the dunes and sastrugi arc gradually worn down by a process of sublimation-deflation. It is this leveling of the surface relief in summer and the resultant redistribution of snow more uniformly over the surface that are believed to be the significant factors in the formation of the systematic stratigraphy observed in pits at the South Pole.
Gravity Measurements on the Devon Island Ice cap and an Adjoining Glacier
Authors: Hyndman R. D.
Published: September 2017

Gravity measurements have been used to determine ice thicknesses across the western part of the Devon Island ice cap in the Canadian Arctic. A detailed profile of the ice-cap edge and a profile across an adjoining glacier are also given. The ice cap has been found to have a largely rock core with ice thicknesses generally less than 500 m. A deep valley has been found in the bedrock beneath the ice cap some 15 km. from the start of a draining glacier. The measured depths on the ice cap should be within 15 per cent and those on the glacier within 20 per cent of the true values.
Net Budget and Flow of South Cascade Glacier, Washington
Authors: Meier Mark F. , Tangborn W. V.
Published: September 2017

Ice velocity, net mass budget and surface elevation change data were collected over the length and width of a small (3.4 km. long) valley glacier from 1957 to 1964. Ice velocities range up to about 20 m./yr.; three prominent velocity maxima along the length of the glacier correspond to maxima in surface slope. Net mass budgets averaged over the glacier surface range between − 3.3 m. of water equivalent (1957–58) and +1.2 m. (1963–64). Except for the year 1960–61, curves of net budget versus altitude are parallel. During the period 1958–61 the glacier became thinner at a rate averaging 0.93 m./yr. The net budget and thinning data are internally consistent. Relations between emergence velocity, net budget and surface elevation change are examined at four specific points on the glacier surface and as functions of distance along the length of the glacier. Emergence velocity averages about −0.5 m. in the upper part of the glacier and about +1.0 m. in the lower part. Ice discharge and ice thickness are also calculated as functions of distance. The discharge reaches a peak of 8.8 × 105 m.3 of ice per year 2.2 km. from the head of the glacier. The mean thickness of the glacier is about 83 m. A steady-state distribution of net budget is used to calculate a steady-state discharge, which is 2.2 times larger than the present discharge.
The Frequency Response of Glaciers
Authors: Nye J. F.
Published: September 2017

The theory developed in previous papers to represent the response of a glacier to changes in the rate of accumulation and ablation has been used for a number of applications. A method of integrating the differential equations for a fixed frequency was programmed for a high-speed digital computer. This provides a better way of finding the frequency response than the earlier method which used series approximations or high and low frequencies. Results are given for (a) an artificial glacier showing varying amounts of diffusion of the kinematic waves, (b) South Cascade Glacier, Washington, U.S.A., as a check on previous results, and (c) Storglaciären, Kebrekaise, Sweden. The response curves of Storglaciären are very similar in shape In those of South Cascade Glacier but, since. Storglaciären moves more slowly, the curves are shifted in frequency (by a factor of two). The phase of the response at the terminus of Storglaciären plotted against frequency shows a double peak.

Certain mathematical results for the artificial case of no diffusion are given in an Appendix.

A computer programme was also written for calculating λ and μ coefficients and applied to South Cascade Glacier and Storglaciären.
Accumulation of Snow in Alpine Areas of Central Colorado and Means of Influencing it
Authors: Martinelli M.
Published: September 2017

The accumulation of snow in terrain depressions was studied in an alpine basin in central Colorado. Snow fences and a jet roof were built up-wind of several natural catchments to see if such barriers could be used in combination with terrain features to produce snow fields that would persist until late summer. At three of the six test sites, fences increased snow depths appreciably and the snow fields persisted longer than usual. At the other test sites snow depths were increased close behind the fences but were decreased farther down-wind with no net increase in the amount of snow caught.
Thickness and Basal Configuration of Lower Blue Glacier, Washington, Determined by Gravimetry
Authors: Corbató Charles E.
Published: September 2017

Gravity measurements at 146 stations on lower Blue Glacier were used to determine the subglacial bedrock configuration. The gravity values, station elevations and density contrast were carefully measured, and terrain corrections thoroughly evaluated to insure accuracy of the Bottguer anomalies. A series of successive approximations results in evaluation of the regional gravity field and a three-dimensional model of the glacier whose gravimetric effects fit the range of the observational and computational errors. Comparison with bore holes and seismic reflections indicates no significant errors in the model and accuracies of 5–10 per cent in the calculated thicknesses of the glacier.
The Bottom Topography of Gulkana Glacier, Alaska Range, Alaska
Authors: Ostenso N. A. , Sellmann P. V. , Péwé T. L.
Published: September 2017

As an extension of an intensive study of Gulkana Glacier a 42 station gravimeter survey was made to gain some insight into its third dimension. This survey showed that the glacier’s main tongue occupies a complex valley composed essentially of two parallel channels separated by a medial ridge which extends southward from rock bastions in the accumulation zone. At mid-glacier the ice thickness in the larger eastern channel is 225 m., in contrast to 130 m. in the western channel. The medial ridge degenerates down-glacier probably disappearing within 2 km. of the glacier terminus. The basic surface flow pattern of the glacier described by Moores can be adequately explained by this basal topography. Seasonal velocity variations are possibly caused by melt-water basal lubrication with one channel being favored over the other at different times of the year, in agreement with observations by Elliston on the Gorner-Gletscher, Switzerland, and with the glacier sliding theory of Weertman.
Foliation Pattern of Gulkana Glacier, Alaska Range, Alaska
Authors: Rutter Nathaniel W.
Published: September 2017

Gulkana Glacier, consisting of three major ice streams and two prominent ice falls, displays a complex foliation pattern. In the western ice stream, below Gabriel Ice Fall, the foliation is transverse, developing gradually down-glacier into a distinct series of nested arcs. The arcs are concave up-glacier with the foliation dipping steeply toward the inside of the arc. A similar pattern is displayed in the eastern ice stream but there the pattern is less distinct with the arcs evolving into a series of nested semi-arcs. The central ice stream is characterized by vertical layers of foliation with a longitudinal strike. Apparently, longitudinal foliation will form in areas with strong compression and shear caused by differential flow velocity such as where two ice streams unite. The foliation that ultimately displays arcuate (or semi-arcuate) patterns originates principally at the base of an ice fall where strong longitudinal compression is present due to the decrease of gradient.
Névé-Capped Snow Pillars Resulting from Ablation on Teton Glacier, Wyoming
Authors: Fryxell Roald
Published: September 2017

Névé-capped snow pillars found on Teton Glacier in August 1956 were formed in the same manner as the ice cones of glacier tables, the névé acting in this instance as the protective cover usually provided by slabs of rock. Measurements of the largest pillar indicate a minimum ablation of 6.5 ft. (1.98 m.) of snow on the surface of Teton Glacier for that summer up to 7 August, and suggest an average rate of snow wastage of 1.5 in. (3.8 cm.) per day during this time. The pillars appear to have been produced by ablation through melting due primarily to direct radiation but supplemented by indirect radiation and conduction-convection influenced by air currents moving across the surface of the glacier.
Dielectric Properties of Ice and Snow–a Review
Authors: Evans S.
Published: September 2017

The permittivity and loss tangent of naturally occurring ice and snow are considered. The direct-current conductivity is considered only when it is of importance to the alternating-current and radio-frequency properties. Laboratory measurements on pure ice, and deliberately contaminated ice, are included to help in explaining and extrapolating the behaviour of natural ice and snow. The lower band of frequencies from 10 c./sec. to 1 Mc./sec. is occupied by a relaxation spectrum in which the relative permittivity falls from approximately 100 to 3. The loss tangent reaches a maximum at a frequency which varies from 50 c./sec. to 50 kc./sec. as the temperature increases from −60°C. to 0°C. We are interested in the effect of snow density, impurities, stress, crystal size, and orientation. For frequencies much greater than 1 Mc./sec., the relative permittivity is 3.17±0.07. The loss tangent reaches a minimum value at approximately 1,000 Mc./sec. beyond which the dominant influence is infrared absorption. The minimum is 10−3at 0°C or 2×10−5at −60°C. These values are greatly increased by impurities or free water. Some possible applications to glaciological field measurements are mentioned.
Seasonal Weather Trends in Relation to Fluctuations of the Jan Mayen Glaciers Since 1920
Authors: Sheard J. W.
Published: September 2017

The meteorological records for Jan Mayen have been examined on a seasonal basis in order to obtain a clearer understanding of the fluctuations of the Beerenberg glaciers from 1920 to the present day. Summer and winter have been arbitrarily defined as including those months with mean monthly temperatures, at sea-level, above and below 0°C., respectively. The results indicate that the retreat of Sørbreen prior to 1940 was associated with high summer temperatures and high summer precipitation, and relatively low winter precipitation. A rapid rise in winter precipitation followed, which culminated about 1950. The advance of Sørbreen since about 1954 is thought to have been caused by this rapid rise of precipitation and has also been associated with a slight drop in summer temperature, which is considered to be of secondary importance. The most recent trends of rising summer temperature since 1956 and falling winter precipitation since 1958, if they continue, must lead to a renewed retreat of the glaciers. Studies on Sørbreen in the summer of 1963, which show that the recent advance has ceased, support this view.
The Formation of Drainage Wind on a Snow-Dome
Authors: Businger J.A. , Ramana Rao K.
Published: September 2017

Direct measurements of the horizontal divergence of the air flow close to the snow surface have been made. The mean vertical wind component has been derived from these observations. The temperature profile has been analyzed near the center of the snow-dome and a method to determine the sensible heat flux independent from the energy budget has been developed.
Long-Term Glacier Variations Measured by Photogrammetry. A Re-Survey of Tunsbergdalsbreen after 24 Years
Authors: Kick W.
Published: September 2017

The relations between geodetic measurements of the surface level variations Δh and net budget measurements by stakes arc discussed. In 1961, 24 yr. after Finsterwalder’s survey, Tunsbergdalsbreen, the largest and most regular of the 26 outlet glaciers of Jostedalsbreen, was re-surveyed. The variations in the length, area, ice thickness, and volume of its tongue are shown. The lake Brimkjelen was 99 m. deep in 1937; it disappeared in 1949. From 1900–40 the whole Jostedalsbre lost 0.4 m./yr., about the same amount as the glaciers of the eastern Alps. The ice thickness of the Tunsbergdalsbre tongue diminished by −ΔhA = 0.46+0.0022 (1500−A) m./yr. from 1937–61; for the eastern Alps from 1920–50 −ΔhA ≈ 0.53+0.0021 (2850−A) m./yr. where A is the altitude. The change of Δh with altitude is much the same. The amounts of the retreat of the Alpine glaciers, of Tunsbergdalshreen, and at Werenskioldbreen, Vestspitsbergen, were the greater the higher the latitude. The numerical relations between Δh, net budget, and ice movement are shown. The temporary velocity transverse profile of 1937 served as a prototype for the streaming mode of flow, but in 1961 the glacier partially showed Blockschollen movement, although the velocity had decreased by more than 30 per cent. The article is accompanied by a map showing ice surface contours in 1937 and 1961.
A Theory of the Consolidation of Snow
Authors: Feldt E. D. , Ballard G. E. H.
Published: September 2017

A consolidation theory is developed for an age-hardened snow under uniaxial stress in the porosity range of 35 to 55 per cent by considering one mechanism, viz. viscous flow of interparticle bonds. For a uniaxial stress σ the differential equation for porosity n in terms of time t is shown to be

where a and ν are structural parameters and η is the coefficient of viscosity of ice. Comparison of this equation and the integrated form with existing data predicts consistent and reasonable values for a. The predicted values of η/ν range from 10−2 to 102 times the published values for, η which may indicate that ν, and hence the consolidation rate, is greatly affected by the diagenetic history of the snow and the conditions of experimentation.
Instruments and Methods Snow Density Profiling by Nuclear Means
Authors: Leighty Robert D.
Published: September 2017

During the period 8–19 May 1963 a preliminary field investigation was conducted in Greenland to determine the feasibility of using a nuclear technique to determine snow and ice density profiles. A standard nuclear soil-moisture depth probe was used with two modes of processing and recording the nuclear pulses. Example data are compared with snow densities obtained by the standard weighing technique. The nuclear method was found to be feasible; however, deficiencies related to poor resolution render the probe unusable for detailed profiling of snow stratigraphy in its present form, but expected progress in nucleonics should enable improved resolution and accuracy to be achieved by improvement of nuclear detectors.
Effect of a Basal Water Layer on the Dimensions of Ice Sheets
Authors: Weertman J.
Published: September 2017

The effect of a basal water layer on the equilibrium dimensions of an ice sheet is examined. A thick water layer can decrease the equilibrium thickness of an ice sheet such as covers Antarctica (which contains no significant ablational areas) by a factor of the order of 2. Similar large changes in the equilibrium dimensions occur for ice-age ice sheets (which have extensive ablation areas). The extent of the ablation area of an ice-age ice sheet which may be covered with morainal debris is also calculated.
A Seismic Reconnaissance in the Mcmurdo Sound Region, Antarctica
Authors: Bell Robin A. I.
Published: September 2017

A portable first-arrival seismic refraction instrument was used to measure seismic P-wave velocities in ice, frozen ground, till and shattered rock at various places in the McMurdo Sound region, Antarctica. It was found that some frozen ground exhibits the same seismic velocity as ice, so that buried ice cannot be idengified by seismic velocity measurements.

The depth of exfoliation of a granite outcrop in Taylor Valley was successfully measured, as was the depth of an ice-free moraine in Wright Valley. From this latter depth, and from reasonable assumptions about the diffusion of water vapour through till, a minimum age of 75,000 yr. has been deduced for the moraine. This age implies that no through-glacier occupied Wright Valley during the last Northern Hemisphere glaciation.
Some Observations on the Climate of Lewis Glacier, Mount Kenya, During the Rainy Season
Authors: Platt C. M.
Published: September 2017

Meteorological observations were made on Lewis Glacier, Mount Kenya, during the “long rains” in April 1960. General meteorological observations indicated rather similar conditions to those found in other months. Ablation occurred on each day but amounts were generally small. Rather more accumulation occurred than is expected during the dry season, but again amounts were small. The net accumulation over a to day period was only 0.38 cm. water-equivalent, although about 30 cm. new snow (about 10 cm. water-equivalent) was lying when the expedition arrived. Detailed observations of short-wave radiation, temperature, wind and humidity with estimates of long-wave radiation were used to calculate the heat balance at the surface of the upper ablation region. Agreement between calculated and measured ablation was reasonably good. Over the periods considered, radiation accounted for 89.5 per cent of ablation, turbulent exchange from the air for 8.0 per cent and evaporation for 2.5 per cent. Subsurface melting was taken into account and the formation of ice bands in terms of such melting is discussed.
Instruments and Methods: Sampling Characteristics of Neutron Probe Measurements in a Mountain Snow Pack
Authors: Cooper Charles F.
Published: September 2017

Advantages of neutron moisture probes over standard snow sampling tubes include integration of water content over a greater horizontal extent, easier measurement of snow layering, and possible increase in accuracy through elimination of the need to extract a full core. However, the neutron probe is better suited for evaluation of water content changes with time at a fixed location, as in soil moisture studies, than for measurement of the total water content of a variable snow pack. Field tests in the mountains of Idaho, U.S.A., showed statistically significant differences among mean snow densities determined by a neutron probe in closely spaced holes at a single sampling station. Within-station variance was about the same as with a conventional snow tube. There were significant differences in density for a given depth from hole to hole, but statistical interactions make it difficult to interpret these differences. There was a poor correlation between measurements made in the same hole with a neutron probe and with a snow sampling tube.
Observations at the Bogvatn Glaciers, Norway
Authors: Theakstone W. H.
Published: September 2017

A description of the two glaciers n. Bogbre and s. Bogbre is given. In summer 1965 snow pillars capped with avalanche material were seen. A blister-shaped swelling which appeared on the surface of s. Bogbre and which emitted water when punctured is discussed.
Fluctuations of the Terminus of the Harald Moltke Bræ, Greenland
Authors: Mock Steven J.
Published: September 2017

The terminus position of the Harald Moltke Bræ has been mapped from existing maps and from aerial and terrestrial photographs for the years 1946–47, 1954, 1956, 1962 and 1965. When abetted by Wright’s earlier work, a fairly detailed record of terminus position exists for the period 1916 to 1965. The glacier has been in nearly continuous retreat during this period interrupted by a slight advance from 1926 to 1932. Loss of area has been accelerating since 1946–47. Ice flow velocity near the terminus has fluctuated through a known range from 30 m./yr. to over 1,000 m./yr.
Two-Dimensional Grain Growth in Ice
Authors: Roos D. v.d. S.
Published: September 2017

The rate of grain growth in thin sections of polycrystalline ice was found to be practically the same at temperatures between 0°C. and −1°C. and not to depend to a great extent upon initial average grain size. In general, several hundred hours of annealing at 0°C. reduced the number of grains by a factor of about 3. The growth rate of certain grains was much greater than the average and these increased about a hundredfold in area. The rate of change of the average diameter was approximately inversely proportional to the annealing time. Grain boundary angles tended to average 120° irrespective of the number of sides per grain. Both grain shapes and crystallographic orientations were found to influence boundary migration rates. After long periods of annealing there was a strong tendency for the surviving grains to have their c -axes oriented parallel to the plane of the ice surface.
Density Variations in Alpine Snow
Authors: Alford Donald
Published: September 2017

Stratigraphic studies of the annual snow layer in the Beartooth Mountains of south-western Montana and on Mount Logan in the St. Elias Range have disclosed a similiar distribution of at least one physical property of the snow pack in the two areas. The average density of the pack, obtained by integrating a series of measurements taken at 5–10 cm. vertical intervals over the total thickness of the annual layer, reaches a maximum value near a mid-point of the total elevation covered by each traverse and decreases linearly toward the elevation extremes. A preliminary hypothesis, relating the distribution of average snow-density values along slopes to a semi-stable zonation of near-surface air temperatures, is presented.
Preliminary Studies on Sea Ice in McMurdo Sound, Antarctica, During “Deep Freeze 65”
Authors: Paige Russell A. , Lee Claude W.
Published: September 2017

The sea ice in McMurdo Sound, Antarctica, is extensively utilized for runways, travel, freight hauling and docking facilities. The safety and efficiency of these operations depend upon a better understanding of the sea-ice bearing strength.

Variations in shear and tensile strength, decreased thickness, salinity changes, internal deterioration and changes of the temperature gradient are all related to and dependent upon snow cover, ambient temperatures and solar radiation. During the austral summer of 1964–65, shear strength decreased from 9.8 kg./cm.2 in October to 6.3 kg./cm.2 in late January and then increased to 8.0 kg./cm2. by 10 February. The salinity of collected brine decreased from 125 p.p.t. in November to 43 p.p.t. in January. Thickness increased until mid-December, then decreased rapidly by bottom melting until break-out in February. In the Cape Armitage shoal area, thickness decreased from 2.5 m. in mid-December to 36 cm. in late January. Snow cover significantly affects the degree of internal deterioration and the amount of strength loss during the summer. Sea ice with more than 6 cm. snow cover is consistently stronger than unprotected ice and deterioration is less. Bearing strength of the sea ice is sufficient for most ordinary loads throughout the period of most extensive use.
Observations on the Snow Line in the Peruvian Andes
Authors: Hastenrath Stefan L.
Published: September 2017

Observations on both the modern and Pleistocene snow lines were made during a journey through the Peruvian Andes. En route observations were supplemented by an evaluation of air photographs in the Servicio Aerofotográfico Nacional in Lima and a survey of the literature. The large-scale variation of the Pleistocene snow-line depression is discussed with respect to possible palaeoclimatic implications.
Accumulation Between Mount Chapman and “Byrd” Station, Antarctica
Authors: Brecher Henry H.
Published: September 2017

In November and December 1965 accumulation measurements were made at 3 km. intervals and at networks of poles at six photogrammetric arrays on an oversnow traverse from Mount Chapman to “Byrd” station. The results at the photogrammetric arrays, which yield a mean accumulation of 16.4 g. cm.−2 yr.−1 for 1963–65, are compared with values determined from stratigraphic investigations in 1958–59 and in 1962–63, which gave 12.2 g. cm.−2 yr.−1 and 13.2 g. cm.−2 yr.−1, respectively.
Electrical Resistivity Measurements and Soundings on Glaciers: Introductory Remarks
Authors: Röthlisberger Hans
Published: September 2017

A brief description of the resistivity method is given, stressing the points which are of particular importance when working on glaciers. The literature is briefly reviewed.
Recent D.C. Resistivity Soundings on Swiss Glaciers
Authors: Röthlisberger Hans , Vögtli Kurt
Published: September 2017

D.C. resistivity soundings have been carried out on Unteraargletscher at three places for comparison with earlier seismic reflection results. While in two cases a fair agreement was obtained, the third sounding indicated a strong inhomogeneity of the ice, making a reliable interpretation impossible. Using the seismic depths in the interpretation, more reliable values of ice resistivities were obtained. Additional apparent resistivities were measured on ice and firn on Grosser Aletschgietscher, which are discussed together with similar results from the literature. The resistivity values of temperate glaciers observed so far fall in the range from 25 to 120 MΩ.m. and are thus significantly higher than the experimentally determined ultimate value of 5 MΩ.m. reported for extremely pure ice at 0°C. by Eigen and others (1964). The necessary conditions fur successful resistivity soundings are discussed.
Growth Modes of Ice Crystals in Supercooled Water and Aqueous Solutions
Authors: Pruppacher H. R.
Published: September 2017

The growth modes of ice crystals in supercooled water and various aqueous solutions were studied at different supercoolings by a motion-picture technique. ln pure water contained in plastic capillary tubes, ice dendrites formed which at supercoolings between 1 and 4°C. grew parallel to the tube axis. At supercoolings larger than 4°C. the direction of growth was inclined to the tube axis such that the dendrites hit the tube wall and afterwards proceeded growing in a new direction. As a result it appeared that the ice crystals grew in a zig-zag or screw fashion. This growth mode became enhanced when the supercooling was increased or salts were dissolved in the water. In large water drops, ice dendrites formed which at supercoolings smaller than 1°C. were co-planar with the seed crystal and between 1° and 5°C. split into two dendritic segments. At supercoolings larger than 5°C. multiple splitting of the seed crystal was observed and this became strongly enhanced when salts were dissolved in the water. Tentative explanations for these results are given.
The Development of a Complex Supraglacial Moraine at the Margin of Sørbreen, Ny Friesland, Vestspitsbergen
Authors: Boulton G. S.
Published: September 2017

A series of concentric debris bands crop out on the frontal stagnant zone of Sørbreen, Ny Friesland, Vestspitsbergen. The contained debris, which is dominantly sand and silt with some clay and gravel, is well sorted and banded, and it is thought to be derived from subglacial fluvial deposits. These debris bands give rise to a complex series of bedded moraine ridges, and bedded and unbedded sediment sheets on the glacier surface.

The development of a supraglacial hummocky moraine is traced and it is composed of several elements: supraglacial ridges, kettle-holes, and flowed sediment sheets, which are derived from debris bands; supra-glacial fluvial deposits and clay-silt ablation tills; and englacial fluvial deposits. It is also suggested that large areas of the outwash plain are underlain by dead glacier ice.

From the present work there are several possible implications for the interpretation of Pleistocene deposits:

i.

Certain types of “controlled disintegration features” may have formed supraglacially from debris bands. Some bedded features hitherto interpreted as Huvioglacial in origin may be supraglacial moraines.

ii.

Certain types of “kame-and-kettle“moraine may be mainly supraglacial in origin.

iii.

Complex sequences of tills and bedded sediments may have been formed during a single glacier retreat phase rather than by multiple advance and retreat.
Holocene Moraines and Rock Glaciers in the Central Ben Ohau Range, South Canterbury, New Zealand
Authors: McGregor V. R.
Published: September 2017

Young moraines and rock glaciers in the central part of the Ben Ohau Range, about 42 km. south of the highest peaks of the Southern Alps, are briefly described. A new formation, the Ben Ohau Formation, consisting of the Ferintosh, Jacks Stream and Dun Fiunary Members, is proposed for moraines and rock glaciers believed to have been built since the climatic optimum by three minor glacial advances. Moraines, and outwash and fan gravels, deposited during a more extensive pre-climatic optimum advance which was contemporaneous with the Cockburn Glacial Phase (Cochrane) in North America are assigned to the Birch Hill Formation. The sequence of glacial advances recorded in the Ben Ohau Range is compared with that found in western North America.
Pleistocene Glaciation in the Atacama Desert, Northern Chile
Authors: Hollingworth S. E. , Guest J. E.
Published: September 2017

Morainic deposits associated with boulder spreads and outwash sands in the High Andes of the Atacama Desert are described and provide evidence of a Pleistocene glaciation. Widespread, locally folded gravel sheets of a similar age may provide a datum for correlating movements resulting in the uplift of the Andes.
The Formation of Shear Moraines: an Example from South Victoria Land, Antarctica
Authors: Souchez R. A.
Published: September 2017

An analysis of the margin of the ice sheet in the upper Ferrar Glacier area of south Victoria Land, Antarctica, shows that the shear hypothesis and the theory of Weertman are both of value if an attempt is made to explain the formation of the morainic deposits of this area.

Three types of debris layer have been observed within the glacier:

i.

Silty and sandy layers, with a slight dip towards the interior of the glacier, are separated from one another by white bubbly ice and blue dense ice at the edge of the glacier. They have resulted from a freezing-in process due to the formation of segregation ice and upwarping near the margin of the ice sheet.

ii.

Fault planes in the glacier, filled with slabs and gravel, are the result of shearing which has occurred along and transformed thermal-contraction fissures. The debris has been scraped from the glacier bed, carried into the ice and ultimately transported along these planes.

iii.

Three coarse debris layers of different ages associated with major shear zones at the boundary between stagnant and active ice.

Due to favourable circumstances, the debris layers of Weertman have been observed to be faulted by shear planes of the second type.