bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Terminal Disintegration of Steensby Gletscher, North Greenland
Authors: Ahnert Frank 
Published: September 2017

AbstractSteensby 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

AbstractDuring 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

AbstractAn 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

AbstractThe 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.
Instruments and Methods: A Simple Thermal Ice Drill
Authors: LaChapelle E. 
Published: September 2017

AbstractA 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

AbstractThe 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

AbstractCarrying 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

AbstractIce 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

AbstractA 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

AbstractLemon 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

AbstractLemon 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

AbstractMeasurements 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

AbstractA 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.
Note on Model Studies of Folding of Moraines in Piedmont Glaciers
Authors: Ramberg Hans 
Published: September 2017

AbstractThe pattern of flow of moraine-carrying glaciers is studied by models whirled in a centrifuge. Because of the rather high centrifugal force (1,000 g), substances with high viscosity, such as bouncing putty and stitching wax (viscosity around 106–107 poises), can be used as glacier-imitation materials. As moraine-imitation material powdered hard wax is used. The strength and high viscosity of the model materials permit detailed structures to be studied without the disturbing effects of sagging after being run to the chosen stage in the centrifuge. Stroboscopic light makes it possible to follow the evolution of the flow and to stop the centrifuge and thus the flow at any stage.Rather realistic-looking fold structures of the kind seen in some piedmont ice sheets develop readily after a few minutes’ run in the centrifuge.The mechanism of fold evolution is discussed.No slip (or shear) has taken place along a “foliation” which sometimes develops parallel to the axial planes of the folds.
Dust-Induced Albedo Changes of Polar Ice Sheets and Glacierization
Authors: Bloch M. R. 
Published: September 2017

AbstractThe custatic changes of the ocean in prehistoric and historical times are linked with the fate of the ocean-based salt industry, and are recognized as erratic. An hypothesis is proposed to explain these erratic changes with albedo changes of the polar ice sheets, caused in turn by erratic volcanic dust fall-out. Ash layers in Antarctic ice cores are connected with historical dislocations of maritime civilizations.Albedo changes associated with the dusting of ice sheets are considered to be the cause of the decline of periods of glacierization generally. Such albedo changes are connected with volcanic activity on the one hand, and loess formation on the other, caused in turn by the growth of the ice sheets.
The Theory of Glacier Sliding
Authors: Weertman J. 
Published: September 2017

AbstractThe theory of the sliding of glaciers presented by the author in earlier papers has been generalized (1) by taking into account the resistance to sliding offered by obstacles both smaller and larger than the controlling obstacles and (2) by relaxing the assumption that ice is always in intimate contact with the bed at the down-stream side of an obstacle. The sliding velocities and controlling obstacle sizes which are found from the generalized theory are approximately the same as those found from the earlier theory. A new result obtained from the present theory is that a water layer an order of magnitude smaller in thickness than the height of the controlling obstacles can cause an appreciable increase in the sliding velocity. The generalized theory contains Lliboutry’s sliding theory as an extreme limiting case. For certain thicknesses of a glacier the sliding velocity is a double-valued function of the shear stress exerted at the bed.
Unconfined Creep of Polar Snow
Authors: O. Ramseier René , L. Pavlak Thomas 
Published: September 2017

AbstractSnow samples from the Amundsen-Scott South Pole station and “Byrd” station, Antarctica, and “Camp Century”, Greenland were tested for creep under low stresses for various periods of time up to two years. Creep was analyzed as a function of density. Comparisons of compressive viscosities plotted against densities for all three sites showed three distinct regions representing three different mechanisms of densification.
Effects of crystallization and plastic flow on the thermoluminescence of ice
Authors: Ronca L. B. , Zeller E. J. 
Published: September 2017

AbstractGlow-curves of ice, made in the laboratory, have a distribution of peak-height ratios, with the maximum at approximately 0.75. The distribution was probably caused by varying conditions of crystallization, impossible to control with the present equipment. Glow-curves of ice which has been made to flow have a distribution of peak ratios with the maximum at approximately 1.75.It is concluded that dislocations in the crystal lattice effect the peak ratio. Dislocations are produced during crystallization by internal stresses, and to a greater extent, by external forces during the flow.
Drumlin Formation Related to Inverted Melt-Water Erosional Marks
Authors: Shaw John 
Published: September 2017

AbstractDrumlin forms are described from maps and air photographs of a part of the Athabasca Plains, northern Saskatchewan. Three major forms, spindle, parabolic and transverse asymmetrical are recognized. These forms, which may show superimposed minor elements, depart from classical descriptions of drumlins, but are similar to moulds of erosional marks created by separated fluid flows. Assemblages of drumlins also show characteristics similar to those of erosional marks. The form analogy between drumlins and moulds of erosional marks is carried to a conclusion that drumlins may be formed by the infilling of erosional marks created on the under-side of glaciers by separated, subglacial melt-water flows. Estimates of specific discharge are obtained by means of an expected range of Reynolds number. Geomorphological evidence is given for large-scale erosion by subglacial melt water. A discussion of the sedimentology, stratigraphy, and deformational structure of the interiors of drumlins shows that they may be explained by the erosional-mark hypothesis. This paper emphasizes the importance of melt water as a geomorphic agent and may have broad implications for ice-sheet dynamics and profiles, rates of deglaciation, and the occurrence of bedrock thrusting by ice.
Early Discoverers XXXIII: John Hardcastle on Glacier Motion and glacial Loess
Authors: Smalley Ian J. 
Published: September 2017

AbstractIn 1890–91 John Hardcastle presented his views on glacier motion and the climatic significance of loess deposits. He should be recognized as a significant pioneer in the study of glacier-flow mechanisms, and more particularly, as the initiator of the study of loess stratigraphy and the multiple-event approach to the formation of loess deposits, especially glacial loess.
Experience with Shear Frames
Authors: Perla R. , Beck T. M. H. 
Published: September 2017

AbstractThe shear frame is a simple in situ device for indexing the shear strength of thin weak layers. The index is sensitive to shear-frame geometry, rate-of-pull, and shear-frame mass. It is time-consuming to carefully align the device on the Gleitschicht (shear failure plane) in a slab avalanche zone. The ratio shear frame index/shear stress of the Gleitschicht has a high variance, and may not be a fundamental measure of slab avalanche stability. Corrections for the normal stress on the Gleitschicht reduce the variance only slightly. Despite these limitations, the shear frame is a useful tool for gathering statistical data on strength distributions and anisotropies of the Gleitschicht until a more fundamental technique is developed.
Theory of glacial erosion, transport and deposition as a consequence of subglacial sediment deformation
Authors: Boulton G.S. 
Published: September 2017

AbstractA theory of erosion, transport and deposition of unlithified sediments by glaciers is presented. It predicts the large-scale areal distribution of zones and rates of erosion and deposition in time and space through a complete glacial cycle, together with the resultant intensity of large-scale lineations (drumlins) which will be incised in the landscape. The theory also predicts the dispersal patterns of subglacial lithologies, together with the form of dispersal trains derived from distinctive sources and the vertical and horizontal distribution of lithologies within a till. It predicts major erosional discontinuities within tills and the formation of boulder pavements. It suggests that the dominant proportion of the lowland tills produced by Pleistocene mid-latitude ice sheets was generated by subglacial deformation and explains why they are predominantly fine-grained.The theory is based on an analysis of glacier-dynamic processes and therefore can be used to infer the dynamic behaviour of former ice sheets from the distribution of tills and their lithologic composition.