bluuebunny/crossref_metadata_2025 huggingface dataset:
Inland Ice Crystal Measurements at Eqe, West Greenland
Authors: Boyé M. , Cailleux A.
Published: September 2017

At Eqe, on the western border of the Greenland Ice Cap, measurements of the crystals by Seligman’s method give a mean crystal diameter of 2.16 cm. at a place where the ice velocity is ceto m.fday. The “heterometry index” measured from granulometric curves by Cailleux’s method shows that melting, active ice crystals have reasonably homogeneous dimensions, with a mean diameter from 2 to 2.4 cm.
The Origin of Penitents
Authors: Lliboitry Louis
Published: September 2017

Penitents are observed on all the snow fields and glaciers of the Santiago Andes between 4000 and 5200 m. They are caused by the prolonged action of the sun in a dry and cold atmosphere, The sublimation of the snow or ice allows the crests to maintain their temperature below 0° C., while in the spaces or passages between the penitents, where radiation is concentrated and removal of water vapour not so easy, melting takes place. This hypothesis is justified by a brief study of the climate of the high Cordillera of Santiago; this study has been attempted for the first time with the help of meteorological information obtained from La Cumbre (3837 m.).

The first stage of the penitents is a form of “micropenitent,” similar to that observed at the end of the winter below 3500 m. These micropenitents frequently come from crusted snow which has cracked. The compact ice penitents are directly formed from ice, as is proved by the existence of ice micropenitents.
The Effect of Accumulation on Temperatures within A Snowfield
Authors: Benfield A. E.
Published: September 2017

The wave of cold temperature, which begins to propagate into a snow field during the winter, may be considerably enhanced by the thermal blanketing of snow accumulating on the surface. This effect is discussed theoretically by means of calculations based on the mathematical theory of the conduction of heat in solids. The results of these calculations show that for an assumed steady velocity of accumulation at the rate of 4 meters/year or 8 meters/year, the winter cold wave should assume significantly larger proportions than in the absence of accumulation.
The Antarctic Pack Ice in Winter
Authors: Herdman H. F. P.
Published: September 2017

A summary of the winter conditions at the edge of the pack ice around Antarctica, as observed on 16 occasions by the R.R.S. Discovery II between 1932 and 1951, is followed by a more detailed account of each visit. The state of the ice on the northern fringe of the pack is noted especially with reference to the various stages in the formation of pack ice. Detailed reference is also made on each occasion to the meteorological conditions obtaining not only during the ship’s stay on the ice edge but for 2 or 3 days beforehand. Despite the limited number of observations possible it would appear that the state or condition of the ice edge, at any one point in winter, is Iargely dependent on local weather conditions, and it is suggested that, basically, the condition of the ice edge falls into three or, possibly four main categories.

Attention is drawn to the possible relationship between the sea surface temperature and the condition of the ice on the fringe of the pack but it is considered probable that the surface temperature has a greater effect on the distribution of pack ice generally, rather than on the state of the ice edge locally.
The Extent of Frozen Ground Under the Sea Bottom and Glacier Beds
Authors: Werenskiold W.
Published: September 2017

The ground in Spitsbergen is frozen to a depth of about 320 m., as can be seen from observations in the collieries. At a mean surface temperature of −8° C. this corresponds to a geothermal gradient of 1°/40 m. The temperature of the sea water is almost 0° C. Along the coast the land lies very little above the sea level, and here the sea is shallow. One assumes that the land as well as the sea bed is horizontal. Thus the temperature on the land is –8° C., in the sea 0° C. On the coast the temperature must suddenly change. One must also take into account the fact that the temperature rises with depth. A simple calculation leads to the conclusion that the frozen ground below the sea bed must extend about 100 m. from the coast. Investigations near a Swedish colliery have shown this to be the case.

This result also applies to the conditions underneath a glacier. On the same assumptions one can conclude that if the glacier is less than 400 m. wide the frozen ground underneath forms one coherent layer and that this is not the case if the glacier is wider. The same applies to a shallow fjord.
Ice Crystals in Glaciers Compared with Quartz Crystals in Dynamically MetaMorphosed Sandstones
Authors: MacGregor A. G.
Published: September 2017

Attention is drawn to resemblances between two contrasted styles of mosaic crystallization—tessellate and equigranular as compared with irregularly interlocking (sutured) and inequigranular—that characterize ice in alpine glaciers and quartz in dynamically metamorphosed sandstones of the Moinian area of the northern Scottish Highlands. It is suggested that in both environments the contrasted types of mosaic are due to crystallization under conditions of shearing stress that were respectively minimal and maximal. Similarities are also pointed out between the orientation of the principal crystallographic axes of crystals in ice subjected to shearing stress, and the “girdle” arrangement of the principal crystallographic axes of quartz in Moinian metamorphic sandstones.
Some Observations on Glacier Flow
Authors: Haefeli R.
Published: September 2017

The excavation of a tunnel by I’Energie Ouest Suisse (EOS) presented inter alia the opportunity to construct a longitudinal profile of the glacier speed and also to observe the speed of the transverse contraction of a circular section. The swift change of shape without fracture was noteworthy. A second tunnel driven from the glacier snout straight up the subglacial stream gave the opportunity to establish a definite connection between the form of the glacier sole and its surface. Finally, measurements of the glacier speeds on the surface and their variations from year to year gave a closer indication of the nature of Forbes’s bands.
Ice Flow Over Bedrock Perturbations
Authors: Budd W.F.
Published: September 2017

The use of well known simple periodic solutions of the two-dimensional biharmonic stress equation for studying the flow over undulations of an ice mass of small surface slope is examined. The model considered is one in which most of the shear (deformation or. sliding) takes place near the base and the upper part moves largely as a block, with longitudinal strain-rates varying linearly with the longitudinal stress deviations. For bedrock perturbations of a given wavelength the steady-state surface shape consists of similar waves but out of phase by ½π, such that the steepest slope occurs over the highest bedrock; and the amplitude is reduced by a “damping factor”, depending on the speed, viscosity, ice thickness and wavelength.

Minimum damping occurs for λm ≈ 3.3 times the ice thickness, while waves much longer or much shorter than this are almost completely damped out. The energy dissipation and the resistance to the ice flow is also a maximum for an undulation scale of several times the ice thickness, whereas the effects of small basal irregularities die out exponentially with distance into the ice, and only have an effect in so far as the average basal stress is related to the average surface slope. As a result of this a revision of present glacier sliding theories becomes possible.

Various predictions of the theory have been confirmed from spectral analysis of surface and bedrock profiles of ice caps.
Radar Soundings on the Penny Ice Cap, Baffin Island
Authors: Weber J.R. , Andrieux Pierre
Published: September 2017

The first successful radar echo soundings through glacier ice in Canada were carried out by the Dominion Observatory in 1965 on an outlet glacier of the Penny Ice Cap in Baffin Island. An unmodified 440 MHz SCR-718 radar altimeter was used, of the type that is readily and inexpensively available on the surplus market. The radar soundings were generally in agreement, within the range of the reading accuracy of the oscilloscope (± 15 m), with depths obtained seismically, gravimetrically, and by the electrical resistivity method. The minimum and maximum recorded depths were 45 m and 550 m, respectively. The pip positions on the standard oscilloscope were recorded visually. This recording method was not satisfactory, but for future use the instrument could easily be modified to incorporate a larger oscilloscope with continuous photographic recording. Use of the relatively high carrier frequency of 440 MHz (compared with the more customary frequency of about 35 MHz) allows the use of smaller antennas and results in better resolution of the bedrock surface.
Internal Deformation and Thermal Anomalies in Lower Blue Glacier, Mount Olympus, Washington, U.S.A.
Authors: Shreve R.L. , Sharp R.P.
Published: September 2017

In 1957 through 1962 six deep holes were drilled by means of specially developed electrically powered hotpoints, 4 cm diameter aluminum pipes were placed in them, and annual inclinometer surveys were made to investigate the deformation field and flow law of the ice at depth. Although a strongly maritime climate with moderate temperatures implies that lower Blue Glacier should be temperate, freezing at depths as great as 200 m, sometimes even in summer, seriously hindered inclinometer surveys. This freezing cannot be due solely to chilling by winter cold and to leakage into initially dry pipes, but may also be due to wintertime changes of water Table in the glacier and to contamination of the ice by antifreeze. Another possibility, residual subfreezing zones carried down from the ice fall, seems unlikely.

Because the relatively inextensible pipe slips lengthwise in the deforming hole, observations of pipe motion at best give only the two components of ice velocity perpendicular to the hole. Thus, a single hole gives two independent equations connecting the nine unknown derivatives of the velocity components; two holes give four equations: and three or more give at most six. Incompressibility of the ice, when applicable gives another. The remaining unknowns must be either neglected or estimated from assumptions about the flow field. At the Blue Glacier holes the longitudinal strain-rate is less than about 0.01 per year, becoming more extensional down-glacier and more compressional at depth, because the holes were moving through a reach in which the surface steepens and the bed becomes more steep-sided and flat-bottomed. Although the effective strain-rates are only about 0.01 to 0.1 per year, so that errors are relatively large, they are in reasonable agreement with flow laws deduced from laboratory experiments by Glen, from tunnel contraction by Nye, and from deformation of Athabasca Glacier bore holes by Paterson and Savage, except that in the range of strain-rates covered the viscosities found for Blue Glacier are about half those derived from the other studies.
Excess Pressure Observed in a Water-filled Cavity in Athabasca Glacier, Canada
Authors: Paterson W.S.B. , Savage J.C.
Published: September 2017

During drilling in the Athabasca Glacier in April 1968, a cavity containing water was punctured at a depth of 9.2 m below the ice surface. Upon removing the drill, water gushed from the bore hole for about 55 s indicating an excess pressure of at least 0.25 bar within the cavity. The surrounding ice was slightly below the pressure melting point, and the excess pressure was apparently generated by the reduction in volume of the cavity caused by freezing of some of the water within it.
Interpretation of the Orientation of Ice Dendrites Growing from Supercooled Water
Authors: Levi Laura
Published: September 2017

An interpretation is proposed of the phenomenon of splitting of ice dendrites growing from supercooled water and of their orientation at an angle α to the basal plane. Both phenomena are related to the instabilities which develop on the dendritic cap when the ratio Vc/Va of the growth velocities in the direction of the c- and a-axes exceeds a certain limit. The different interface supercoolings, (δTi)a and (δTi)c at the tip and at the sides of the dendrite cap are considered. Although Vc/Va increases with the bath supercooling ΔT it is found that Vc ≪ Va for (δTi)c = (δTi)a through the whole range investigated (o < ΔT ≤ 18 deg). The increase of α with the concentration of solutes is also qualitatively explained. Considering the kinetic theory of the molecular growth mechanism, the results obtained for Vc as a function of (δTi)c would indicate that most of the studied interval must correspond to the transitional regime of growth.
Late Weichselian Potholes Near Wolverhampton, England
Authors: Morgan Alan V.
Published: September 2017

Three potholes and a narrow channel cut into bedrock in a side-hill position were observed beneath an Irish Sea till west of Wolverhampton, England. The potholes and the channel are believed to have been cut by subglacial or latero-glacial streams flowing beneath or immediately beside the Irish Sea ice sheet. They were later choked by sand and gravel from this ice sheet and capped by till which ended the glaciofluvial deposition. Deposits below and above the till have been 14C dated at 30 655 and 13 490 years B.P. at localities between 13 and 27 km north of the trench section described.
The Early History of Glacial Theory in British Geology
Authors: Hansen Bert
Published: September 2017

Much of the history of British geological thought in the second quarter of the nineteenth century centered on problems which are now explained by reference to the events of the Ice Age. This paper reviews the data and theories then current among British geologists as the background of the British response to Louis Agassiz’s “modern” theory of a glacial epoch. Today, as we read Agassiz’s amazing speculation, our own sympathy for the striking accuracy of his ideas masks from us the difficulty they faced in gaining acceptance. By first examining the context into which the glacial theory was introduced, we can then appreciate the novelty of Agassiz's efforts and understand the long delay in their achieving prominence. The present examination suggests that this delay was due to the unfortunate merger of Agassiz’s new ideas with the older drift theory of Charles Lyell.
Glacier Maps of Canada
Authors: Henoch W.E.S. , Stanley A.
Published: September 2017

This note describes the series of seven maps at scales 1 : 1 000 000 showing the distribution of glaciers in Canada, with indication of information sources.
A Possible Relation Between Grain Size, Density, and Light Attenuation in Natural Snow Cover
Authors: Bergen James D.
Published: September 2017

The extinction coefficient for the transmission of light through snow cover is related to the grain size and density of the snow cover. The connection is made by means of an empirical relation between the latter parameters and the air permeability and by the Carmen–Kozney relation between the air permeability and specific surface of a porous medium. The results are compared with a set of measurements found in the literature with fair agreement between the predicted and measured values of the extinction coefficient.
Effects of a Debris Slide on “Sioux Glacier”, South-Central Alaska
Authors: Reid John R.
Published: September 2017

The lower one-third of “Sioux Glacier” in south-central Alaska was buried beneath a debris slide during the 27 March 1964 earthquake. Investigations to determine the effect of this cover on the regimen of the glacier revealed that it has increased in thickness by as much as 28 m, primarily as a result of the insulating effect of this debris cover. In areas where debris has continuously veneered the surface, at least since 1938, the ice is also thicker. A longitudinal profile reveals that the area near the upper extent of the slide debris has become intensely crevassed and has been lowered as much as 8 m between 1965 and 1966, while the terminal area is up to 5 m higher and is characterized by thrusting. It is concluded that a kinematic wave passed through this glacier sometime between 1965 and 1966.

The upper zone of debris-veneered ice is moving at 175 m/year while the terminal area is flowing at only 21 m/year. The rate of down-glacier decrease in velocity is about 0.06 m/year per meter of horizontal distance except for an area approximately 1 km from the terminus. Here, the rate of decrease in velocity is 0.1 m/year per meter. The change in rate is presumed to be related to topographic control caused by the recent thinning of the ice here.
The Mechanical Properties of Single Crystals of Pure Ice
Authors: Jones S. J. , Glen J. W.
Published: September 2017

Results obtained from tensile and compressive tests on pure ice single crystals at various temperatures down to −90°C are reported. At −50°C tensile creep tests give a continually increasing creep rate until fracture, as observed at higher temperatures. The stress dependence of the strain-rate is discussed. Fracture stress increases with decreasing temperature. Results from constant strain-rate compressive tests are compared with theoretical curves computed from Johnston’s (1962) theory of dislocation multiplication. A dislocation velocity of the order of 0.5×10−8 m s−1 is deduced for ice at −50°C.
Glaciar Yanasinga (Central Peru): 24 Years of Measurements
Authors: Petersen U. , Sassarini L. , Plenge R.
Published: September 2017

Glaciar Yanasinga (lat. 11° 36′ S., long. 76° 12′ W., 4850 m a.s.l.) is probably one of the few glaciers in the equatorial region on which measurements have been performed during the last 24 years. These were carried out in the years 1944, 1945, 1946, 1947, 1948, 1949, 1957, 1963 and 1968. The results of these surveys are presented on a map and references are given for those interested in obtaining more detailed information.
I.G.Y. Glaciological Work at Wilkes Station, Antarctica
Authors: Hollin J. T. , Cameron R. L.
Published: September 2017

The Wilkes Station area comprises 75 km.2 of rock which form one of the most extensive exposures on this part of the East Antarctic coast. During 1957 and 1958 the continental ice sheet south-east of Wilkes Station was explored to a distance of 100 km. inland, and its form and behaviour studied by means of topographic, movement and gravity surveys. Surface stake measurements inland showed a net accumulation equivalent to 13.7 cm. of water in 1958. Sub-surface measurements of wetness, hardness, density, grain size, crystal size, shape and fabric and electrical conductivity were made at 60 locations and to depths which reached 62 m. at an auxiliary inland station. Meteorological observations were made and englacial temperatures measured. In summary, the ice sheet in this area provides a typical section of a polar glacier. The evidence for glacial fluctuations and the possibility of establishing a chronology for these are discussed.
The Response of Fjord Glaciers to Changes in the Firn Limit
Authors: Mercer J. H.
Published: September 2017

Glaciers in fjords almost always reach standstill positions at the fjord mouths or at changes in their width. Between such positions the terminus is usually advancing or retreating: the advance may be anomalous compared to glaciers on dry land in the vicinity, and the retreat may be catastrophically rapid. These peculiarities of fjord glaciers can be at least partly explained by considering conditions to be expected in an ideal fjord of constant width: the glacier cannot reach equilibrium by changing the extent of its ablation area or its calving terminus, and these cannot change their altitude with respect to sea-level in response to a rise or fall in the firn limit.
Measurement of Firn Motion by a Magnetic Prospecting Method
Authors: Lliboutry L.
Published: September 2017

The compaction and flow within névé can be studied by means of magnetized steel tubes buried in vertical pits. The locations of the tubes, their distances from the surface, down to a depth of 10 m., and their angles with the vertical can be determined from measurements made with a B.M.Z. magnetometer.
A Tentative Theory of Ogive Formation
Authors: King C. A. M. , Lewis W. V.
Published: September 2017

The dark and light bands on glaciers known as ogives are only found beneath ice falls and avalanche fans. They are not to be confused with sedimentary layering, which may appear similar. Vareschi’s pollen studies are considered in relation to the present theory; his evidence is re-interpreted and shown to support the theory put forward.

The Norwegian glacier Austerdalsbreen has a fine double set of ogives, one set on ice from Odinsbreen and the other on ice from Thorsbreen. These ogives are continuous from near the feet of these ice falls down to the end of the main glacier. The ice from the collecting ground of Jostedalsbreen which moves slowly towards the head of these ice falls is normally stratified as seen in the deep crevasses immediately above the ice falls. The high velocity of flow, 2,000 m. per year in the upper part of Odinsbre ice fall, causes the ice to stretch into a thin and heavily crevassed layer which exposes a very high proportion of surface per unit volume to the sun, the rain and the snow. In summer this leads to:(1) crystal changes, primarily of enlargement, (2) an infusion of dirt which blows on to the glacier from the neighbouring snow-free and vegetation-free land surfaces, and (3) water filling the bottom of some of the deeper crevasses, which may later freeze. On the other hand, the ice which passes down the ice falls in winter is largely protected by a mantle of snow; crystal changes then are slow, little dust collects, and less water pours into the crevasses which, instead, are filled with new snow. So the ice reaching the lower part of the ice falls and moving on to form the main glacier, Austerdalsbreen, has been subjected throughout its mass to seasonal differences. These differences seem to be more systematic in the deeper ice, and only when the chaotic surface layers are melted away, do they appear on the surface of Austerdalsbreen as well defined ogives. The greater proportion of blue, bubble-free ice with large crystals in the “summer” ice, is alone sufficient to distinguish it from the lighter-coloured “winter” ice with its more frequent bands of white bubbly ice having very small crystals. But as ablation continues, more and more dust is brought to the surface and this still further darkens the “summer” ice. In addition the darker ice melts more readily and tends to form troughs in the glacier surface which retard stream flow, hold the lingering snows, and trap further dust and dirt. The cracks between large crystals also hold dirt better than the smooth hard white surfaces which occur more frequently in the “winter” ice. Hence the ogives remain distinct throughout their journey down Austerdalsbreen. Near the snout the medial moraine is very abundant along the darker bands deriving from Thorsbreen, and this further supports our view that this darker ice was in the ice fall in summer when most debris falls from the rock walls on to the ice fall.
New Zealand Glaciations and the Duration of The Pleistocene
Authors: Gage Maxwell
Published: September 2017

Recent work has resulted in recognition of an additional glaciation preceding the Waimaunga Glaciation in the late Pleistocene. This followed the mid-Pleistocene climax of earth movements responsible for most of the present mountainous relief of New Zealand, but only after an interval of time long enough for the construction and subsequent deep dissection of Banks Peninsula shield volcano. It is inferred from this and other geological evidence that the earliest late Pleistocene glaciation was separated from the early Pleistocene Ross Glaciation by several hundred thousand years, and that the Pleistocene Period altogether covers at least one million years.
Theory of Performance of Isothermal Solid-Nose Hotpoints Boring in Temperate Ice
Authors: Shreve R. L.
Published: September 2017

The performance of a thermal ice-drill having a smooth, solid, impervious frontal surface, termed a “solid-nose hotpoint”, is determined by the velocities, pressures, and temperatures in the thin layer of warm melt water between the hotpoint and the ice. The efficiency, the speed of penetration, the temperature of the frontal surface, and the distribution of pressure on it can be calculated from the equations of non-turbulent fluid flow. For hotpoints whose frontal surfaces are isothermal and axially symmetric, these quantities are functions of the total input of power Q of the weight W on the hotpoint, of the radius a and “shape factor” S of the frontal surface, and of the pertinent physical properties of water and ice. The calculation shows that with increasing “performance number” the efficiency E decreases and the surface temperature θ0 increases. Thus, for example, E = 1·00 and θ0 = 0°C. when N = 0.0 E = 0·76 and θ0 = 48°C when N = 1.4; and E = 0·60 and θ0 = 103°C. when N = 3.0. The coefficient Λ is a constant equal to . The shape factor S is a dimensionless number between 0 and 1 that varies according to the shape of the frontal surface, greater values of S being associated with blunter profiles (thus S = 1.0 for a plane frontal surface perpendicular to the axis). For coring hotpoints the same numerical results are obtained, but the performance number is given by

where 2ϖia is the inside diameter of the hotpoint.
Investigation of Shear Zones in the Ice Sheet Margin, Thule Area, Greenland
Authors: Swinzow George K.
Published: September 2017

The structure of silty ice bands and the formation of their resulting shear moraines are investigated in the light of new evidence provided by two ice tunnels and additional surface investigation in the general Thule area. Previous investigations are examined and discussed; a new interpretation of the phenomena is presented.
Mass Balance Studies in Kebnekajse
Authors: Schytt Valter
Published: September 2017

The mass balance of Storglaciären in Kebnekajse, Swedish Lappland, has been studied in some detail sine 1946. Out of sixteen budget years, fourteen have given a deficit, one a surplus and one has been balanced. It is emphasized that more attention should be paid to the accuracy needed for significant mass balance studies. At present the density of the observation network on Storglaciären is 120 observations per km.2 for accumulation and 13 observations per km.2 for ablation measurements. The net loss during the sixteen years of observation amounts to nearly 10 per cent of the total glacier volume, and it is suggested that the principal cause of this loss is the increase in the mean summer temperature.
A New Advance of the Jan Mayen Glaciers and a Remarkable Increase of Precipitation
Authors: Lamb H. H. , Probert-Jones J. R. , Sheard J. W.
Published: September 2017

A new advance since about 1954 of the glaciers descending on all sides of the great volcanic mountain Beerenberg (2,277 m.) on the island of Jan Mayen (lat. 71° N., long. 8° W.) has been reported. Annual precipitation in the area appears to have risen fairly steadily and in the 1950’s had almost doubled as compared with the 1920’s. Other places around the Greenland Sea show substantial increases of precipitation after 1920 as compared with the 1910–20 rate, but mostly attained a maximum in the 1930’s or around 1940. Periodicities are briefly discussed as well as secular change. Temperatures at Jan Mayen have fallen somewhat since the 1930’s but they have not altered much since the 1940’s. The likely causes in terms of changes of the atmospheric circulation and other circumstances, including lag in the glaciers’ response, are briefly discussed. The increase of precipitation seems to be the main, almost the sole, causative factor in the glacial advance.
Orientation Fabrics in Lake Ice
Authors: Lyons J. B. , Stoiber R. E.
Published: September 2017

Laboratory experiments and field observations permit an explanation of the varying crystallographic orientations observed in lake ice in terms of four factors: (1) coincidence of the plane of most rapid growth in ice (the basal plane) with the vector of thermal flux, (2) mechanical fragmentation of early-formed dendrites and plates by winds above a critical velocity (approximately 2.7 m./sec.), (3) the presence of a sufficiently thick layer of supercooled water to permit vertical crystal growth, and (4) the operation of geometric factors, first pointed out by Perey and Pounder, which result in the gradual elimination of the flatter plates of growing ice by the steeper ones.
Heat Conduction in Thinning Ice Sheets
Authors: Jenssen D. , Radok U.
Published: September 2017

A numerical treatment of the heat conduction in ice sheets subject to vertical shrinking, geothermal and frictional heating from below, and surface accumulation or ablation, is outlined and illustrated with results computed for an arbitrary ice thickness profile. The movement of the ice is found to increase its basal temperature when the ice is thick, and to decrease it in the fringe zone where the ice becomes thin. The treatment seems capable of extension to cover both the thermal and dynamic aspects of ice motion.
Glaciological Observations on the Ross Ice Shelf Near Scott Base, Antarctica
Authors: Stuart A. W. , Bull C.
Published: September 2017

On the Ross Ice Shelf near Scott Base the annual surface snow accumulation is about 18 g.cm.−2. The increase of firn density with depth is greater than normal, due to horizontal compaction. Where the bottom of the ice shelf has a density less than 0.8 g.cm.−3 the shelf becomes brine-soaked by vertical infiltration. The bottom of the shelf is melting, at about 44 g.cm.−2 yr.−1 where the bottom is impermeable ice and 73 g.cm.−2 yr.−1 where the bottom is permeable firn. Surface velocities at 40 points within 30 km. of Scott Base vary between 4 and 840 m.yr.−1. From the pattern of velocities, ice thicknesses and surface features, a transition zone is delineated, separating the Ross Ice Shelf from the “McMurdo Ice Shelf”.
The Glaciers of Jan Mayen
Authors: Kinsman D. J. J. , Sheard J. W.
Published: September 2017

A descriptive account of the glaciers of Jan Mayen is given, based on the results of two recent University of London expeditions. The positions of most of the glacier snouts are compared with previous records and a general advance of the ice margin is reported. The discovery of massive tillite deposits low down in the volcanic sequence is thought to confirm the post-Pleistocene origin of the present Beerenberg mountain. An outline of the geological and topographical evolution of the mountain is related to the history of its glaciation. Three major advances of the ice margin are described, the most recent having taken place within the last 350 years. The transient nature of high-altitude rime structures is demonstrated.
Glaciations of the Pindar River Valley, Southern Himalayas
Authors: Ahmad N. , Saxena H. B.
Published: September 2017

The Pindari Glacier is situated in the heart of the Kumaon Hills in lat. 30° 17′ N. and long. 80° 0′ E. This glacier was visited by the authors in October 1959 when morphological and other observations were made. On the basis of these observations, it appears that during the last hundred years the rate of retreat of this glacier has been phenomenal, and it may be as much as 132 ft. (40.2 m.)/yr. There is also evidence that in the past the Pindari valley suffered at least two glacial advances.
Two Tunnels in Cold ice at 4,000 m. on the Breithorn
Authors: Fisher Joel E.
Published: September 2017

A description is given of two tunnels, each 60–70 m. long, one directly above the other, at 4,000 and 4,020 m, a.s.l. excavated through cold firn and ice of the Breithorn in the Alps. The temperature rose from −5.5° C. at the portal to −0.5° C. at the rock interface 70 m, from the portal in the upper tunnel, and from −5.5° C. to 0° C. at a water reservoir 60 m. from the portal in the lower tunnel. In both cases cracks or minute sealed crevasses, cut by the tunnel, operated to cool the ice locally below the temperature to be expected from a smooth curve. Possible. origins of the water reservoir are discussed.

Small amounts of air at a moderate pressure, enclosed in small, sealed cracks and hollows, were punctured between 60 and 70 m. from the portal in the upper tunnel. The pungent odor of the air thus released was identified as ozone (a) by its characteristic odor, (b) by its reaction on rubber, and (c) by potassium iodide starch paper tests. The source of such ozone is suspected to be minute electric sparks resulting from static electric charges built up in cold ice when it is subjected under pressure to cracking or deformation; Photographs taken with exposures of 8 hr. in the upper tunnel at night apparently show such sparks.

A description is given of the appearance of cold ice, frozen to the bedrock, being forcibly tortured into streamers and bands by the movement of the entire ice body at 0.6 m./yr.
The Terminal Disintegration of Steensby Gletscher, North Greenland
Authors: Ahnert Frank
Published: September 2017

Steensby Gletscher, located between Nyeboes Land and Warming Land, is one of the few Arctic ice streams with a floating tongue. It differs from other floating glaciers of the Arctic in that it discharges into a fjord with open water in the summer, in the presence of crevasses on its floating tongue, and in the way its terminus disintegrates areally into sublobes rather than shedding “Arctic” type icebergs by simple calving.

The glacier’s terminal disintegration is ascribed to a slight northward bend of the fjord stretch which contains the floating tongue. The tongue, moving into the bend along a straight path, runs marginally aground near the shore at the outside of the bend, while the still-floating central part of the tongue continues to move forward. This leads to rotational movement of parts of the tongue which split off from the main ice mass along major crevasses to form sublobes separated from each other by wide gaps, and connected with the main ice mass only at their roots.
Seismic Reconnaissance on an Ice-Covered Antarctic Sea
Authors: Cook John C.
Published: September 2017

During the I.G.Y. seven geophysical stations were occupied on the semi-permanent sea ice of inner McMurdo Sound, Antarctica. Three more were occupied on the floating tongue of the Koettlitz Glacier. Seismic refraction, reflection and S-wave propagation studies yielded preliminary data on the configurations of the ice cover and a profile of the bottom of the sound. The bottom slopes smoothly to a depth of 627 m. at the center of the sound. Secondary reflections indicate the presence of an unconsolidated layer on the bottom at some points. The glacier tongue near its seaward edge has a fairly uniform thickness of about 45 m.
An Unusual Ice Formation on the Ottawa River
Authors: Gold L. W. , Williams G. P.
Published: September 2017

An unusual humped formation of floating ice, about 10 m. high, 100 m. wide and 1,200 m. long. was observed on the Ottawa River, Canada. Some characteristics of this formation are described. The cause of the humps was found to be frazil ice deposited in a trench about 90 m. wide, 90 m. deep and 1,200 m. long. The frazil ice was formed in rapids up-stream from the humps.
Observations on the Glaciers of the Ruwenzori
Authors: Whittow J. B. , Shepherd A. , Goldthorpe J. E. , Temple P. H.
Published: September 2017

The glaciological work of six expeditions from Makerere University College to the Ruwenzori between December 1957 and July 1961 is described and some results are given.

The history of glaciological research in the Ruwenzori mountain range is outlined and the present ice distribution is described. A variety of evidence is presented to illustrate the pattern of change over the last 50 years, and all the glaciers examined are shown to have been drastically reduced in size, with an apparent acceleration in melting since the 1940’s. Six glaciers are known to have disappeared completely, whilst several others have split into smaller units.

A detailed survey of the Speke Glacier on Mount Speke was made, and calculations show that if the present trends continue all the ice below 4,573 in. on Mount Speke can he expected to disappear within the next 40 years.

The Elena and Savoia Glaciers on Mount Stanley and the Moore Glacier on Mount Baker are described, and recessional rates for each glacier are calculated. Measurements of the ice movement of the Elena Glacier demonstrate that it is still a fairly active glacier, although the Moore Glacier is thought to be completely stagnant. Other scientific measurements of glaciological significance include subglacial temperatures for the Elena Glacier, melt-water flow rates from the Speke Glacier and solar radiation measurements for several stations near the Ruwenzori ice margins.
The Kolahoi Northern Glacier, Kashmir
Authors: Odell N. E.
Published: September 2017

During a visit on 31 August 196 1 to this glaciel', which is situa ted a bout 35 miles (56 km. ) east-north-east of Srinagar, it was noticeable that a considerable recession of the snout had taken place since its position was as shown on the one-inch Survey map of 19 12, and also on the reduced half-inch sheets of 1922 and 1943, all of which a restill in current, but politically restricted, use. There has been retreat in the interval of about half a mile (0·8 km.), i.e. from the lower open valley to the vicinity of the north face of Mt. Kolahoi, where it descends in a nice fall fed chiefly by the upper glacier basin to the west.
Instruments and Methods: A Simple Thermal Ice Drill
Authors: LaChapelle E.
Published: September 2017

A thermal ice drill using a silicon carbide electrical resistance element has been developed. The silicon carbide element is operated bare in water, permitting a very simple and efficient drill design. Maximum operating power density in these elements is limited to 400 W./cm.3 by the tendency of wet silicon carbide to deteriorate rapidly at high current levels. The elements are readily replaceable and have a drilling life of 40 to 70 m. of hole. Normal drilling rates in ice of 5 to 6 m./hr. can be consistently maintained with 220 W. power input to the drill.
Glaciological Studies on Ice Island T-3
Authors: Muguruma Jiro , Higuchi Keiji
Published: September 2017

The nature of candle ice, stratified ice and ice of radial structure observable on ice island t-3 was investigated. Cores were drilled through the ice island at two sites. Crystallographic examination, and visco-clastic and chlorinity measurements, were made all along the cores. Results indicate that the ice body of t-3 is composed of three strata; the stratum above a heavy dirt layer is composed of iced firn which shows a granular nature with crystalline facets; that below the dirt layer is “basement ice”; and at the bottom is a sea-ice layer 1.8 m. thick. The basement ice is subdivided into four strata. Petrographic studies of dirt samples obtained from the surface and from the ice cores were carried out by an X-ray diffraction method; from the results, the dirt is thought to be dust of Precambrian granite or gneiss, which are the prevailing rocks in Ellesmere Island. The structure of t-3 was inferred from assumptions based on the data obtained from the core drillings at the two sites.
Accumulation in the Region of Wilkes, Wilkes Land, Antarctica
Authors: Black H. P. , Budd W.
Published: September 2017

Carrying on from the work initiated over the I.G.Y. period by the United States glaciological parties at Wilkes (cf. Hollin and Cameron, 1961), members of the Australian National Antarctic Research Expeditions have continued accumulation stake measurements to 80 km. inland on the plateau (lat. 66° 31′ S.) and extended them south 480 km. (to lat. 71° S.). These stake measurements, supplemented by pit data and surface observations, supply a comprehensive account of the accumulation in this region; how it builds up during the year, how it varies from year to year and how it is affected by topography.
Ice Lithologies and Structure of Ice Island Arlis II
Authors: Smith David D.
Published: September 2017

Ice island ARLIS II, which is adrift in the Arctic Ocean, is a 1.3 km. wide and 3.8 km. long fragment of shelf ice 12–25 m. thick, which preserves several structural features heretofore undescribed in ice. The island is composed of an irregular central block of foliated, locally debris-rich, grey glacial ice bordered in part by extensive areas of stratified bluish sea ice. The central block contains a series of narrow, elongate, sub-parallel dike-like septa of massive fresh-water ice and a large tongue-like body of tightly folded, coarse banded ice. Both the septa and the tongue cut across the foliation and debris zones of the grey ice.

The margins of the central block are penetrated by a series of elongate, crudely wedge-shaped re-entrants occupied by salients of bluish sea ice. Two broad, arch-like plunging anticlines deform the stratified sea ice along one margin of the block.

The foliation and debris zones in the glacial ice are relict features inherited from the source glacier. The septa formed as crevasse and basal fracture fills. Salients represent fills formed in the irregular re-entrants along the margins of the glacial ice mass. The tongue of tightly folded, banded ice represents an earlier generation salient deformed by compressive forces as the fill built up. The broad anticlines are apparently the result of warping in response to differential ablation but the small, tight plunging folds on their noses and limbs are probably the result of compressive forces.
Ice Core Studies of Ward Hunt Ice Shelf, 1960
Authors: Ragle R. H. , Blair R. G. , Persson L. E.
Published: September 2017

A four-man party representing the Arctic Institute of North America and the Department of Geology, Dartmouth College, went to the Ward Hunt Ice Shelf in 1960 to obtain ice cores for subsequent laboratory analysis. The overall objective of the project was to study the structural and stratigraphic history of the shelf and its relationship to the environment through laboratory analysis of the cores, using stratigraphic. petrologic, chemical, and physical methods.

The four cores obtained were logged, packed, and shipped to Dartmouth College for detailed study. The stratigraphy and structure of the ice were studied under natural and plane polarized light conditions. The results of this initial work showed that the cores were composed of four ice types: glacier ice, lake ice, sea ice, and transition ice. Chlorinity, sulfate, and density profiles complemented megascopic studies and were most useful criteria for plotting stratigraphie changes in ice type.

Results of the investigations thus far have yielded new information about the gross structure and stratigraphy of the ice shelf and re-entrant. They have also shown that the physical and chemical techniques employed will be useful in future ice-core analysis.
Surface Movement, Hydrological Change and Equilibrium Flow on Lemon Creek Glacier, Alaska
Authors: Heusser Calvin J. , Marcus Melvin G.
Published: September 2017

Lemon Creek Glacier served as the focus of attention of the Juneau Ice Field Research Project from 1953 through 1958. During the International Geophysical Year, it represented one of the glaciological stations in the North American network. This paper presents some of the results of these studies, its purposes being (1) to discuss the 1953–58 annual hydrological budgets, and (2) to test Nielsen’s equations for the equilibrium glacier using 1957 and 1958 movement and hydrological data.

It is found that each budget year for the period studied shows a deficit, except 1954–55 which registered a pronounced surplus. The net deficit amounts to 10.32×106 m.3 of water. The 1956–57 budget was only slightly negative (0.82×106m.3) but that for 1957–58 was strongly negative (8.96×106 m.3). Surface flow measurements were made along five transverse profiles, two of which were plotted over one full year. It is believed that the one-year measurements provide a more accurate and realistic picture of glacier flow than is normally available from short summer surveys. Thu glacier appears to be close to equilibrium and to behave in the manner predicted by Nielsen’s theory of equilibrium flow.
Historical Variations of Lemon Creek Glacier, Alaska, and Their Relationship to the Climatic Record
Authors: Heusser Calvin J. , Marcus Melvin G.
Published: September 2017

Lemon Creek Glacier served as the focus of attention of the Juneau Ice Field Research Project from 1953 through 1958, during which period glaciological and related research was accomplished. This paper provides an historical framework for those studies by (1) considering variations of Lemon Creek Glacier in recent centuries and during millennia since the last ice age, and (2) describing certain relationships which appear to exist between these variations and the climatic record.

It is found that Lemon Creek Glacier has been receding intermittently since a maximum c. 1750 and by 1958 had lost c. 25 per cent of the former area. Most rapid recession occurred during the periods 1891–1902 and 1929–58. Behaviour of the glacier since c. 1750 reveals a parallelism with glaciers in most of the regions where temperature trends have been graphed as well as with other glaciers of the Juneau Ice Field. The advances of the 1950’s observed in the Rocky, Cascade and Olympic Mountains do not, however, show up in the Juneau area. Lemon Creek Glacier has not advanced more than 375 m. beyond the 1750 position, if at all, during the last 10,000 yr.
Flow Rates and Secondary Structures of Fox and Franz Josef Glaciers, New Zealand
Authors: Gunn Bernard M.
Published: September 2017

Measurements have been made of the flow rates of two adjacent glaciers in Westland, New Zealand. A longitudinal flow foliation is developed in one (Franz Josef Glacier) and this was found to be associated with more or less constant rates of flow down the length of the glacier tongue. In the other (Fox Glacier) the foliation is of the transverse type and is associated with a high strain-rate in ice under compression with markedly decreasing rates of flow being found down the length of the glacier. The highest strain-rates are associated with tectonic dirt bands and thrusts.
Structural Glaciology of an Ice Layer in a Firn Fold, Ross Ice Shelf, Antarctica: Ice Grain Analysis
Authors: Reid John R.
Published: September 2017

A highly deformed area in the Ross Ice Shelf near the Bay of Whales was studied during the 1958–59 Antarctic summer season. A series of snow-firn folds up to 8 m. high and with a wavelength of approximately 100 m. occurs here. Along one of these folds, a unique ice layer formed during the 1952–53 season through refreezing of melt water. From sites along this layer approximately 2,300 ice grains were measured using the root mean square method with the least circle diameter. The data obtained indicate the following:

The mean diameter of the ice grains ranges from 4.5 mm. in the ice from the crest of the anticline to 2.5 mm. in the zone of maximum shear stress and/or in sections having a high air bubble content.

The large diameter of the ice grains at the crest is attributed to greater solar radiation resulting from their proximity to the 1958–59 snow surface, and because they are near the surface of the exposed crevasse wall.

The area of maximum shear stress, which is represented by small ice grains and the presence of secondary folds, is located almost halfway between the crest and the trough.

Grains in the trough are larger than those in the shear zone because of less stress, and smaller than those at the crest because of deeper burial and the presence of a crevasse bridge which eliminates all direct radiation here.

The growth of the ice grains is therefore controlled by temperature, stress and impurities.