bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boulder Polygons and Stripes in the Cairngorm Mountains, Scotland
Authors: King R. Bruce 
Published: September 2017

AbstractMeasurements of widths, diameters and boulder sizes of patterned ground in the Cairngorm Mountains indicate two sorts of stripes and polygons (fine and coarse). Pipkrake and boulder-inclination observations and measurements suggest that fine polygons are produced by heave and their sizes are dependent upon the frequency of boulders large enough to be resistant to heave, which in turn depends upon climatic severity. The lack of orientation, angle of boulder inclination, hemispherical shape, high relative size dispersion and lithological dependence of coarse polygons indicate a selective weathering origin. The frequency of low inclination of boulders in stripes suggests an origin due to solifluction, whereby large immobile or relatively slower-moving boulders impede soil (and smaller boulder) movements and control stripe spacing. Movement observation and lichenometry indicate that fine polygons and stripes and bare coarse polygons are active at the present time and that coarse stripes and vegetated coarse polygons probably date from the Little Ice Age.
Short Note: Finite-Element Stress Analysis of Avalanche Snowpacks
Authors: Smith F. W. , Sommerfeld R. A. , Bailey R. O. 
Published: September 2017

AbstractThe elastic stresses have been determined, in a single-layer homogeneous snowpack on a realistic avalanche slope, by a two-dimensional finite-element analysis. Calculation of the state of stress throughout the 0.96 m snow layer on a slope approximately that of the Lift Gully at Berthoud Pass, Colorado, resulted in reasonable stress values. In particular, both field experience and the calculated shear stresses predict avalanching in the lower-density snows. Also, tensile stresses were present only in the area of the observed fracture line.
Analysis of Glacier Run-Off and Meteorological Observations
Authors: Gudmundsson Gudmundur , Sigbjarnarson Guttormur 
Published: September 2017

AbstractLinear models of the relationships between meteorological observations and the flow of river Tungnaá at the western margin of glacier Vatnajökull were investigated by means of spectral analysis and estimation of the impulse response. Most of the variation of Tungnaá is confined to the lowest frequencies and the diurnal variations. The temperature has most effect on the rapid variations around 1 cycle/day whereas the largest coherences with the precipitation are in the lowest frequencies. The wind explains over 20% of the variations in the frequency range from 0–1 cycle/day, but this is partly due to its coherence with the precipitation. The time lag between changes in the temperature and the river is about 2 h, but the time lag between precipitation and the river is longer. Analysis of longer records of daily observations from Ϸjórsá shows that the coherence of the run-off and temperature increases at frequencies too low to be estimated from these data. At frequencies over 1 cycle/day most of the observed variations of the river cannot be explained by means of a linear relationship with the meteorological series.
Creep of Ice Containing Dispersed Fine Sand
Authors: Hooke Roger LeB. , Dahlin Brian B. , Kauper Michael T. 
Published: September 2017

AbstractCylindrical samples of ice with 0.0 to 0.35 volume fraction fine sand were tested in unconfined uniaxial compression at stresses between 5.3 and 6.4 bar and at temperatures between −7.4 and −9.4° C. Secondary creep rates were obtained from the slope of the total strain vs. time curve and were normalized to 5.6 bar and −9.1° C. Creep rates in ice with low sand concentrations were in some cases higher and in other cases lower than in clean ice. However at higher sand concentrations the creep rate decreases exponentially with increasing volume fraction sand. The latter results are in general agreement with theories developed to explain dispersion hardening of metals, and suggest that each sand grain is surrounded by a tangled network of secondary dislocations which impede passage of primary glide dislocations.
Power Spectrum Analysis of Undersea and Surface Sea-Ice Profiles
Authors: Hiblek William D. , LeSchack Leonard A. 
Published: September 2017

AbstractUnder-ice sonar profiles and surface laser profiles of the Arctic pack ice have been analyzed using power-spectrum techniques to extract significant spectral peaks corresponding to spatial periodicies in the ice. The analysis suggests that, for a section of ice sampled by two intersecting under-ice profiles, the ridges are not randomly oriented. Moreover, the lineation or directionality of the ridges may be approximately determined from the two intersecting profiles. Also the spectra from surface profiles of multi-year ice and from surface profiles of first-year ice are of a much different nature, thus suggesting a technique for determining ice types from laser profiles.
Elastic Stresses in Layered Snow Packs
Authors: Smith F. W. 
Published: September 2017

AbstractA two-dimensional finite element computer program has been used to compute the elastic stress distribution in realistic multi-layered snow packs. Computations have been done on three-layered and five-layered snow packs intended to simulate conditions on the Lift Gully at Berthoud Pass, Colorado. Calculations have been performed to determine the effect of a layer of new snow and the effect of a weak sub-layer. Stress levels were obtained which are reasonable compared with available snow strength data.
Temperature Distribution in the Upper Layers of the Ablation Area of Athabasca Glacier, Alberta, Canada
Authors: Paterson W. S. B. 
Published: September 2017

AbstractTen-meter temperature measurements show that Athabasca Glacier is temperate in the accumulation area but not in the ablation area. An important factor in determining whether all the ice will reach a temperature of 0° C by the end of summer is how much of the layer of ice, cooled during the previous winter, is removed by ablation. However, calculations show that, even when allowance is made for ablation, not enough heat is conducted into the ice to bring it all to the melting point. As recent work suggests that ice at 0° C is permeable to water, latent heat released by refreezing of percolating melt water is considered; it appears likely that this process is an insignificant heat source in the ablation area. Available data show that the penetration of solar radiation can probably also be neglected. The question of how widespread temperate glaciers are is discussed; it is predicted that in most, if not all, glaciers there is a region below the equilibrium line where, because ablation is low, the glacier is not strictly temperate.
Measurements of Water Pressure in Moulins as Part of a Movement Study of the White Glacier, Axel Heiberg Island, Northwest Territories, Canada
Authors: Iken Almut 
Published: September 2017

AbstractIn 1970 water pressure was measured in several moulins on the White Glacier. Pressure variations in some moulin channels extended over the full measuring range of the instruments (0–1 and 0–2 bar above atmospheric pressure), even at depths of less than 50 m below the surface. Measurements at different depths showed that total pressure variations were sometimes greater than this. The pressure data are compared with variations in the surface velocity of the glacier.
Snow Accumulation at “Byrd” Station, Antarctica
Authors: Gow A. J. , de Blander F. , Crozaz G. , Picciotto E. 
Published: September 2017

AbstractThe rate of snow accumulation at “Byrd” station, Antarctica, was measured by various methods. Surface measurements yield a mean accumulation of 117 kg m−2 year−1 for the time interval 1962–70, within a 10 m radius of the station. The distribution of fission products with depth indicates a rate of 67 ± 4 kg m−2 year−1 for the period 1955–68 and of 100 ± 10 kg m−2 year−1 for the period 1965–68. The 210Pb method yields a 60 year average of 110 ± 10 kg m−2 year−1.
Seismic Refraction and Reflection Measurements at “Byrd” Station, Antarctica
Authors: Kohnen Heinz , Bentley Charles R. 
Published: September 2017

AbstractSeismic refraction and reflection shooting was carried out along three profiles about 10 km long, angled 60° to one another, near “Byrd” station, Antarctica, during the 1970–71 field season. No dependence of velocity upon azimuth was found, but velocities at 200 or 300 m depth were slightly greater than at a site 30 km away where measurements were made in 1958. The difference can probably be attributed to different ice fabrics arising from a 50% difference in snow accumulation rates at the two sites. The velocity depth and density–velocity functions at the two sites are also significantly different, but close agreement was found at each site between the depths to significant changes in the velocity gradient and the depths of fundamental change in the densification process. Such agreement may permit density–depth curves, and consequently accumulation rates, to be measured by seismic refraction shooting alone.The reflection shooting on a common reflection-point profile led to a good determination of mean velocity through the ice as a function of angle of incidence. The results agree closely with similar measurements at the 1958 site, and with an anisotropic model based on glaciological and sonic logging observations in the deep drill hole. The mean vertical velocity of 3.90–3.93 km/s through the solid ice is about 2% higher than has commonly been used for determinations of ice thickness from seismic reflection shooting.
A Photogrammetric Survey of Hoseason Glacier, Kemp Coast, Antarctica
Authors: Morgan Peter J. 
Published: September 2017

AbstractA study of Hoseason Glacier was made to test whether photogrammetry could yield meaningful glaciological information from repeated series of air photographs without ground control. Three maps indicate that large time differences, different camera systems, and the use of sea ice as a level datum do not present insurmountable difficulties in photogrammetric reduction. Surface horizontal movement was determined and level profiles were compiled. Hoseason Glacier is probably in equilibrium.
Morphology of the Ice-sheet Margin Near Thule, Greenland
Authors: Hooke Roger Leb. 
Published: September 2017

Three types of glacier margin are found along the edge of the Greenland ice sheet near Thule: ice cliffs, ramps and ice-cored moraines. Where the glacier margin is perpendicular to prevailing katabatic winds, drifting snow accumulates along it in stagnant wind-drill ice wedges. Upward flow of active ice behind these wedges causes ice originally near the base of the glacier to rise to the surface. Where this basal ice is free of debris, a gently sloping ramp develops. However, where the basal ice contains sufficient debris, a layer of till accumulates on the glacier surface. Ice beneath the till is insulated and a debris-capped ice ridge or ice-cored moraine forms, Ice cliffs occur where the ice-sheet margin is parallel to prevailing winds and is thus swept clear of drifting snow. Although the ice sheet in the Thule area appears to have had a negative mass balance for many years, all three types of glacier margin are believed to be equilibrium forms that can develop and persist on a glacier with a balanced mass budget.Foliation in wind-drift ice wedges generally dips down-glacier but foliation in active ice dips up-glacier. It is inferred that foliation in the wedges was once sedimentary stratification that has been tipped upward and locally overturned.
The Possible Importance of Electrical Forces in the Development of Snow Cornices
Authors: Latham J. , Montagne J. 
Published: September 2017

Measurements were made of the vertical electric field Strength around snow cornices on Bridger Ridge (2 590 m a.s.l.) in the Bridger Range, South-western Montana. The fields were considerably enhanced, owing to the exposed position of the cornices, but were nevertheless appreciably lower than those shown by Latham and Saunders (1970[b]) to be necessary in order to provide significant additional bonding when ice crystals collide with an ice surface. However, measurements made on Bridger Ridge and neighbouring Bangtail Ridge showed that the charges carried on snow crystals saltating over the surface of cornices were close to their limiting values.Rough calculations indicated that pressure melting is unlikely to be of importance in the development of snow cornices formed from granular crystals, that frictional melting is probably significant only at fairly low temperatures and moderately high wind velocities, and that strong electrostatic forces between highly charged snow crystals saltating over the surface of a cornice may be sufficient to provide bonding where the crystal velocities are comparatively low.
Studies of the Shrinkage After a Sudden Advance, Blue Bands and Wave Ogives on Glaciar Universidad (Central Chilean Andes)
Authors: Lliboutry Louis 
Published: September 2017

AbstractThe recently discovered Glaciar Universidad is the second largest glacier in central Chile. Aerial photographs taken in 1945 show that just before that date it had undergone a “glacier flood” or sudden advance, similar to those suffered by four other great glaciers of central Chile between 1927 and 1947. The cause of these floods is sought. Surface features (firn line, absence of penitentes but presence of “pocket-penitents”, glacier mills, dirt cones, water-filled holes with submerged ice crystals in them) prove that Glaciar Universidad is the most northerly glacier in the Andes of an Alpine type. The disposition of blue bands, crevasses, closed crevasses and shear planes is reported. Wave ogives are studied and an explanation is given of why dark Forbes’ bands form subsequently on these waves. A kind of unstratified esker of a form similar to a deposit observed by Mr. W. H. Ward in Baffin Island, has been studied, as also has the shearing of the frontal cliff along dirt strata; a theory of both phenomena according to which shear transfers material from the bed to the surface is questioned.
On the Formation of Snow Penitentes
Authors: Amstutz G. C. 
Published: September 2017

AbstractAn attempt is made to throw some light on the physical processes in the development of penitentes as a result of new observations in Peru and a study of the literature. This paper offers a variety of approaches to the problem rather than any final view or theory, and is therefore mostly suggestive and intended to be a program for further, more detailed research.
The Summer Climate in the Accumulation Area of the Salmon Glacier
Authors: Adkins C. J. 
Published: September 2017

AbstractDuring the summer of 1957 a party visited the Salmon Glacier in British Columbia. A meteorological station was established in the accumulation area at an altitude of 1700 m. From 12 June to 16 August pressure, temperature and humidity were recorded continuously and the daily totals of precipitation, ablation and percolation were obtained. Periodic measurements of snow density were made; on the first occasion to a depth of 4.7 m. and later near the surface only. Occasional observations of snow temperatures to a depth of 12 m. were also made. Towards the end of the season the heat balance of the snow surface was examined in detail. The various contributions to the melting are evaluated for several short periods and their relative magnitudes compared.
The Knife Creek Glaciers of Katmai National Monument, Alaska
Authors: Muller Ernest H. , Coulter Henry W. 
Published: September 2017

AbstractA group of previously unmapped glaciers on the slopes of Trident and Katmai Volcanoes, southwestern Alaska, was studied for information on the abnormal regimen produced by effects of the 1912 eruption of Mount Katmai. During the eruption an area of 5 square miles (13 km.2) of the summit above regional snow line was destroyed, and the beheaded glaciers were buried under a blanket of pumice and ash. Field data are presented to indicate that the terminus of Fourth Glacier has been essentially stationary since the 1912 eruption. Upper portions of the glacier have thinned, exposing the rim of the caldera which 40 years ago was partly ringed with fringing ice cliffs. Permafrost has developed to within a few feet of the surface of the pumice mantle. Under prevailing climatic conditions Fourth Glacier may be preserved in its present static condition for an indefinite period.
Deformation of Floating Ice Shelves
Authors: Weertman J. 
Published: September 2017

AbstractThe problem of the creep deformation of floating ice shelves is considered. The problem is solved using Glen’s creep law for ice and Nye’s relation of steady-state creep (the analogue of the Lévy-Miles relation in plasticity theory). Good agreement is obtained between an observed creep rate at Maudheim in the Antarctic and that predicted from the results of creep tests made by Glen.
Temperature Measurements at a Cirque Bergschrund in Baffin Island: Some Results of W. R. B. Battle’s Work in 1953
Authors: Thompson H. R. , Bonnlander B. H. 
Published: September 2017

AbstractThermograph, thermistor, and thermometer readings at a 30 m. deep bergschrund from June 6 to July 22, 1953, showed that there was little direct relationship between air temperatures outside and at the bottom of the Schrund. The air temperature inside ranged from −3.7° C. (253° F.) to +0.5° C. (32.9° F.), but from July 2 onwards it oscillated between –0.5° C. and +0.5° C., with a 3–4 day periodicity. The ice temperature at the bottom of the schrund behaved similarly, though it was about 0.5° C. colder. The oscillations may have been caused by the interplay of flowing melt water (source of heat) and air drainage in quiet weather (source of cold). The granite-gneiss headwall, where not sheathed by refrozen melt water, appeared to be chemically and mechanically unweathered, which supported the conclusions of Battle’s earlier tests in deep bergschrunds and in the laboratory.
Sorge’s Law of Densification of Snow on High Polar Glaciers
Authors: Bader Henri 
Published: September 2017

AbstractErnst Sorge, a member of Wegener’s Greenland Expedition 1930–31, discovered an important law on the densification of snow in high polar glaciers. It is here given a simple mathematical form and some of its implications are formulated and discussed. Apart from its significance to glaciology and snow mechanics, Sorge’s law should also be useful in the study of consolidation of accumulating fine-grained lacustrian and oceanic sediments.
The Glaciological Studies of The Baffin Island Expedition, 1950: Part V: On The Variation of The Shear Stress on The Bed of An Ice Cap
Authors: Orvig Svenn 
Published: September 2017

AbstractSome recent work by Dr. J. F. Nye on the calculation of the thickness of ice sheets has prompted the author to apply Nye’s formula to the Barnes Ice Cap in Baffin Island. A gravimetric survey of the southern lobe was carried out in 1950, and the data from four of the traverses have been used to calculate the variation of the shear stress on the bed. Some of the values obtained are exceptionally low, possibly explained by the fact that the lines of travel over the surface do not necessarily correspond to the lines of greatest slope or lines of flow. Only in one direction are the values relatively high, and it is concluded that there is a considerably greater movement of the ice in this direction. This conclusion is in agreement with observations on the ground.
Local Pleistocene Glaciation and the Level of the Snow Line of Croaghaun Mountain in Achill Island, Co. Mayo, Ireland
Authors: Farrington A. 
Published: September 2017

AbstractThe group of corries on Croaghaun Mountain on Achill Island is described. The existence of these corries and the absence of any extraneous drift from the mountain is taken as evidence that the inland ice of Co. Mayo did not extend far beyond the present coast. The relation of the corries to the local topography is described, and the effect of the topography on the apparent snow line is discussed. The probable snow line of the main glaciation of the west of Ireland is shown to be in the neighbourhood of 1250 ft. O.D. (384 m.) but may have been as low as 1000 ft. O.D. (305 m.) and that of the Late-glacial period in the neighbourhood of 1750 ft. O.D. (533 m.).
More About Advancing and Retreating Glaciers in Patagonia
Authors: Lliboutry Louis 
Published: September 2017

AbstractContrary to prevailing opinions, the glaciers of south Patagonia have normally been stationary or have advanced during the last twenty years. Exceptions can be accounted for by a lag due to a long travel through narrow passes or by the lowering of waters in the terminal lake at the foot of a rocky cliff.
On the Causes of Palaeoclimatic Variations and of the Ice Ages in Particular
Authors: Öpik E. J. 
Published: September 2017

AbstractA method of quantitative climatological analysis is developed by applying the principle of geometric similarity to the convective heat transport, which is assumed to vary with the 1.5 power of temperature difference. The method makes possible the calculation of the change in the mean annual, or seasonal temperature, produced by a variation in insolation, cloudiness, snow cover, etc.It is shown that the variations in the orbital elements of the earth cannot account for the phenomena of the ice ages; the chronology of the Quaternary, based on these variations, has no real foundation.Palaeoclimatic variations are most probably due to variations of solar luminosity. These can be traced to periodical re-adjustments in the interior of the sun, produced by an interplay between nuclear reactions and gas diffusion, repeating themselves after some 250 million years. Complications from the outer envelope of the sun lead to additional fluctuations of a shorter period, of the order of 100,000 years to be identified with the periodical advance and retreat of the glaciers during the Quaternary.Calculations of the variations of luminosity in a star of solar mass substantiate this hypothesis.
Thermal Regimen of Firn on Upper Seward Glacier, Yukon Territory, Canada
Authors: Sharp Robert P. 
Published: September 2017

AbstractTemperatures were measured within the firn and ice of the upper reaches of the Seward Glacier (referred to in this paper as the “upper Seward Glacier”) to a depth of 204 ft. (62.2 m.) by means of thermohms and a Wheatstone bridge. Thermal boring proved a feasible means of penetrating this glacier. The winter’s chilled layer here develops a thickness of 40–50 ft. (12.2–15.2 m.) and attains temperatures of at least −13° C. Deterioration of the chilled Iayer is rapid and irregular in the final phase and is attributed largely to freezing of percolating melt water. Melt water exerts such a powerful influence on thermal regimen that bodies of firn in environments with mean annual temperatures below freezing may, nonetheless, be geophyaically temperate because of extensive warming by melt water in summer. In both 1948 and 1949, the annual chilled layer on the upper Seward Glacier disappeared within the first 10 days of July. The slow development and rapid deterioration of diurnal crusts on firn and the lag effects at depth reproduce in miniature the behavior of the annual chilled layer. On the basis of its thermal regimen the upper Seward Glacier is geophysically temperate.