bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of Englacial Profiles in the Lake Hazen Area of Northern Ellesmere Island
Authors: Hattersley-Smith G. 
Published: September 2017

AbstractGlaciological research on the ice cap to the north of Lake Hazen in northern Ellesmere Island was one of the main objectives of the Canadian I.G.Y. expedition to this area in 1957–1958. The method of nourishment of this ice cap and of Gilman Glacier, one of its southward-flowing outlets, was studied in pit and bore hole profiles above and below the equilibrium line, which was found at an elevation of about 1,200 m. Between an elevation of about 1,450 and 2,000 m. accumulation is by firn formation, while between about 1,280 and 1,450 m. interfingering of firn and superimposed ice occurs. At 1,800 m. the mean annual accumulation over the past twenty years is estimated as 12.8 g. cm.–2. On Gilman Glacier below the equilibrium line variations in density and crystal structure in an ice core to a depth of 25 m. are seen to depend on the proportion of firn to superimposed ice formed during accumulation. These variations correspond to past changes in the position of the equilibrium line. Englacial temperature measurements indicate a mean annual temperature of about –18.5° C. at an elevation of 1 ,040 m. A budget deficit for Gilman Glacier during two years of observations may be related to the increased summer melting of the last 20 years, deduced from pit studies at 1,800 m.
A Subglacial Gorge: La Gorge Du Guil (Hautes-Alpes)
Authors: Tricart J. , Soons J. M. 
Published: September 2017

AbstractThe Gorge du Guil (Hautes-Alpes) might be regarded as a typical example of a post-glacial gorge. In fact, this is not the case. Systematic and very detailed observations based on maps of the scale of 1 : 5,000 have revealed that the greatest part of the excavation of the defiles, cut across the bands of massive rocks, was accomplished by subglacial melt waters. Remnants of glacial deposits containing well-rounded pebbles, but whose finer constituents have been largely removed, occur a few metres above the present valley floor in each of these defiles. The down-cutting was very powerful, being facilitated by the crevassing of the ice, which was at the most 300 m. thick, over the ridges and in the constricted sections of the valley, and by the load carried in the englacial melt water. The sheltered and sunny climate, and the situation of the area below the limit of permanent snow also favoured erosion by melt water. By comparison, post-glacial down-cutting has been slight, not exceeding some ten metres in the massive strata, and appears to have been far less rapid than the subglacial erosion.
The Role of Diastrophism in the Regimen of Glaciers in the st. Elias District, Alaska
Authors: Miller Maynard M. 
Published: September 2017

AbstractThe “earthquake avalanche” theory was invoked by Tarr and Martin in 1914 to explain anomalous turn-of-the-century glacier advances in Yakutat Bay, Alaska. The concept was given credence by the fact that this bay was the epicenter of a series of severe earth tremors in the autumn of 1899.In considering alternative explanations, Tarr and Martin dismissed a record of excessive precipitation along this coast in the late 1870’s and 1880’s in the belief that the measurements were in error due to a “peculiarity in the method of measurement”. The disputed data are now known to be consistent with observed and inferred regional climatological trends in the latter half of the 19th century. The case for the climatological control of glacier fluctuations in the St. Elias District is therefore reassessed. Reference is made to new and extensive evidence from other districts in southern Alaska where the earthquake influence was negligible. It is concluded that the fluctuation pattern in the Yakutat area was not unique and that the diastrophism to which these particular resurgences have been attributed was actually but a supplemental and generally minor factor in a widespread set of glacial advances initiated by climatological causes.The theoretical implications of changes in load conditioned by climatological parameters over the broad névés of the St. Elias Mountains are briefly discussed with respect to orogenic activity in this tectonically sensitive region.
The Formation of Dirt Cones on Mount Ruapehu, New Zealand
Authors: Krenek L. O. 
Published: September 2017

AbstractDue to the abnormally warm summers of 1955 and 1956 the glaciers of Mount Ruapehu deteriorated to such an extent that the ash layer of the eruption of 1945 was exposed everywhere. This caused a development of ice cones similar to those occurring in Iceland. Various factors, especially heavy crevassing, which took place at the same time, are responsible for the different ways of development of dirt cones on Ruapehu.
New Evidence of High-Level Glacial Drainage in the White Mountains, N.H.
Authors: Hattin Donald E. 
Published: September 2017

AbstractA newly discovered pothole field in the White Mountains, N.H., is described, and is attributed to action of melt water from the last continental glacier. Discordance of pothole orientation with slope direction is explained by inferring the presence of a retaining wall of ice which controlled stream flow direction during the period of pothole formation. The potholes constitute the highest evidence of continental glacial drainage yet known in New England.
Glacier Mechanics in the Perfect Plasticity Theory
Authors: Lliboutry Louis 
Published: September 2017

AbstractThe author agrees with Nye’s correction of two errors in a previous paper; but disagrees with his other objections. Evidence is put forward for the significance of a second approximation in the theoretical equation for the profile of a glacier; for instance, it explains why bulges of increased thickness travel down glacier faster than the ice. Features of the front of the Glacier de Saint-Sorlin are reported. An attempt is made to explain crevasse formation in glaciers and the upturning of blue bands at the foot of an ice fall.
Precipitation Trends in Greenland During the Past Thirty Years
Authors: Diamond Marvin 
Published: September 2017

AbstractThe record of annual precipitation as obtained from stratigraphic studies on snow profiles in the interior of northern Greenland made in 1954 by SIPRE personnel shows a decreasing precipitation trend since 1920 with the largest decrease occurring since 1932. A residual mass curve analysis of the data indicates that, in spite of large fluctuations in the accumulated precipitation, the decreasing trend may be considered valid over a period of several years.
The Salt Content of Some Ice Samples From Nordaustlandet (North East Land), Svalbard
Authors: Gorham Eville 
Published: September 2017

AbstractAnalyses for pH, Na+, K+, Ca2+, Mg2+, HCO3−, Cl−, SO42− and NO3− have been made on land ice samples from Nordaustlandet, Svalbard. Total ions range from less than 0.02 to 0.46 milli-equivalents per litre, with sea salt generally the dominant component although calcium and magnesium bicarbonates are relatively more abundant in a surface sample heavily contaminated by soil material from an adjacent moraine. These ions, as well as potassium and sulphate, are present in most samples in excess of possible sea-spray supply. From the surface of a crevasse to 14 m. depth down one side the concentrations of all ions except nitrate fluctuate in a similar manner. Some possible implications of the results are examined.
Movement Observations on the Greenland Ice Sheet
Authors: Wallerstein George 
Published: September 2017

AbstractDuring the summer of 1955 certain positions on the Greenland Ice Sheet that had been established by the French in 1951 were redetermined by observations of the sun in order to measure the motion of the surface of the ice sheet. A motion of 774 meters in four years in a southerly direction was noted at the Central Station. A motion of 611 meters in a westerly direction was noted at the French Mile 100. The uncertainty of the measures is large when the time scale is as short as four years, and expeditions to this area are urged to remeasure these positions and extend the markers for future use.
Changes in a Shallow Snow Cover Subject to a Temperate Climate
Authors: Gold L. W. 
Published: September 2017

AbstractObservations were carried out on each significant layer of the snow cover at Ottawa (lat. 45° 24′ N., long. 75° 43′ W.) on the thickness of the layer, and the density, grain size distribution and degree of bonding of the snow in each layer. A logarithmic dependence on time was found for the layer thickness, and the density and grain size distribution. The product of layer thickness times the corresponding snow density was found to be constant when no melting occurred.
An Investigation of Some Soil Polygons in Central Iceland
Authors: Dybeck M. W. 
Published: September 2017

AbstractNear the edge of Langjökull ice cap there are many soil polygons. A cross-section showed them to be only surface features consisting of rocks in polygonal form embedded in silt. The area revealed much evidence that silt and small rocks often behaved like a liquid upon which heavier rocks would float. If the floating heavier rocks were pushed down into the “liquid,” mud would, in certain circumstances, ooze up a metre or so away. If a number of rocks were depressed the mud would ooze at points roughly equidistant from a few of the rocks, and spread to leave a polygon pattern. Conditions favourable for the sinking of heavy stones in this manner probably occur each spring.
Exfoliation Joints and Ice Action
Authors: Harland W. B. 
Published: September 2017

AbstractSome generally accepted views on joints in rocks, particularly exfoliation joints, are summarized. Lewis’ pressure release hypothesis is assessed in relation thereto. An additional hypothesis is suggested whereby the existing stress system in rocks due to the removal of overburden which would favour exfoliation, would be augmented by freezing of the saturated rock when the ice retreats, so triggering this type of extension joint.
Banding and Volcanic Ash on Patagonian Glaciers
Authors: Lliboutry Louis 
Published: September 2017

AbstractOn aerial photographs of the Patagonian ice fields several types of bands can be identified; (1) fine ogives similar to Lüder’s lines in metals; (2) dirt bands which are both the outcrop of the annual debris strata of the névé and melt borders (the Schmelzrände of von Klebelsberg); (3) annual wave ogives below some ice falls; (4) annual ogives in regenerated glaciers, the formation of which is studied; (5) large melt borders which occur at longer intervals as a result of volcanic eruptions. These latter give evidence on the volcanic activity in the middle of the Patagonian ice fields.
Ablation Polygons on Snow—Further Observations and Theories
Authors: Richardson W. E. , Harper R. D. M. 
Published: September 2017

AbstractA general description of ablation polygons is given and variations from widely distributed regions are examined. After discussion of the conditions in which they most frequently develop, possible explanations are considered, leading to the conclusion that the polygons result from ablation by turbulence in the surrounding air, and that the dirt fringes to the polygons may be explained by the “normal trajectory” theory.
The Old Moraines of Pangnirtung Pass, Baffin Island
Authors: Thompson H. R. 
Published: September 2017

AbstractThe “old moraines” of Pangnirtung Pass were constructed by trunk glaciers, tributary glaciers, glacial streams, rockfalls, talus-creep and other agents and processes. Rivers have since reworked or removed the deposits lying along the axis of the Pass and have begun to dissect the remainder. The old moraines have ice cores, which have tended to melt, collapse and flow downhill, thus further complicating the drift topography. The freshness of many old-moraine fronts implies a recent warming up of the climate, which is also reflected in the decay of the modern giaciers; but erosional undermining may also cause fresh fronts. Although no accurate date can be assigned to the disappearance of the trunk glaciers, A.D. 500 is given as a tentative estimate. There have since been at least two main advances of the tributary glaciers, of which the first followed close on the disappearance of the trunk glaciers and the second occurred not later than 1850.
Glacier Observations in North-West Spitsbergen
Authors: Mellor M. 
Published: September 2017

AbstractResults of observations on several glaciers in the Kongsfjord area are described, and comments are made concerning accumulation and ablation, glacier flow and the variation of glacier fronts. The findings are compared with those of previous workers in this district and, in particular, with those of H. W. Ahlmann. A history of the fluctuation of several ice fronts during the present century has been compiled from various sources, and some observations dating back to 1837 are mentioned.
Preliminary Results of Research on Snow and Avalanches in Czechoslovakia
Authors: Vrba Miloš , Urbánek Bedřich 
Published: September 2017

AbstractThis paper gives a brief account of the results so far obtained in research in Czechoslovakia on the crystallographic, stratigraphical and thermal properties of snow cover, and the use of these data in avalanche investigations. Avalanche danger is predicted by comparing the penetration resistance of snow layers, measured with a rammsonde, with resistance graphs of typical avalanche situations.
The Use of the Rammsonde as an Instrument for Determining the Density of Firn
Authors: Bull C. 
Published: September 2017

AbstractIt has been found that in the cold firn of the Greenland Ice Sheet a direct relationship exists between the specific gravity of a layer and its “resistance to penetration” as measured with a Rammsonde. Corrections which should be applied to the measured “resistance” to allow for the frictional resistance of the walls of the hole on the Rammsonde tube are discussed. In certain circumstances these corrections can be estimated with reasonable accuracy for tube lengths up to three metres. The statistical method of obtaining the relationships between “resistance” and specific gravity is briefly outlined, and the effect of the size of the snow grains is also considered. It is shown that under these particular conditions it is possible, from measurements of “resistance”, to estimate the specific gravity of a firn layer with a standard error of 0.04, when the specific gravity of the sample is in the range 0.3 to 0.57.
Inland Ice Crystal Measurements at Eqe, West Greenland
Authors: Boyé M. , Cailleux A. 
Published: September 2017

AbstractAt 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

AbstractPenitents 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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractAttention 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

AbstractThe 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

AbstractThe 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

AbstractThe 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.