scholarly journals Gravity Measurements on the Devon Island Ice cap and an Adjoining Glacier

1965 ◽  
Vol 5 (40) ◽  
pp. 489-496 ◽  
Author(s):  
R. D. Hyndman
Keyword(s):  
Canadian Arctic ◽  
Devon Island ◽  
Ice Cap ◽  
Gravity Measurements ◽  
True Values

Abstract Gravity measurements have been used to determine ice thicknesses across the western part of the Devon Island ice cap in the Canadian Arctic. A detailed profile of the ice-cap edge and a profile across an adjoining glacier are also given. The ice cap has been found to have a largely rock core with ice thicknesses generally less than 500 m. A deep valley has been found in the bedrock beneath the ice cap some 15 km. from the start of a draining glacier. The measured depths on the ice cap should be within 15 per cent and those on the glacier within 20 per cent of the true values.

scholarly journals Gravity Measurements on the Devon Island Ice cap and an Adjoining Glacier

1965 ◽  
Vol 5 (40) ◽  
pp. 489-496
Author(s):  
R. D. Hyndman
Keyword(s):  
Canadian Arctic ◽  
Devon Island ◽  
Ice Cap ◽  
Gravity Measurements ◽  
True Values

AbstractGravity measurements have been used to determine ice thicknesses across the western part of the Devon Island ice cap in the Canadian Arctic. A detailed profile of the ice-cap edge and a profile across an adjoining glacier are also given. The ice cap has been found to have a largely rock core with ice thicknesses generally less than 500 m. A deep valley has been found in the bedrock beneath the ice cap some 15 km. from the start of a draining glacier. The measured depths on the ice cap should be within 15 per cent and those on the glacier within 20 per cent of the true values.

scholarly journals Form and flow of the Devon Island Ice Cap, Canadian Arctic

2004 ◽  
Vol 109 (F2) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. A. Dowdeswell ◽  
T. J. Benham ◽  
M. R. Gorman ◽  
D. Burgess ◽  
M. J. Sharp
Keyword(s):  
Canadian Arctic ◽  
Devon Island ◽  
Ice Cap

scholarly journals Reports on Current Work Temperatures in the Devon Island Ice Cap, Arctic Canada

1976 ◽  
Vol 16 (74) ◽  
pp. 277
Author(s):  
W.S.B. Paterson
Keyword(s):  
Steady State ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Climatic Warming ◽  
Devon Island ◽  
The Past ◽  
Ice Cap ◽  
Last Glaciation ◽  
Temperature Ranges ◽  
The Difference

Abstract Temperatures have been measured in a 299 m bore hole that reaches the base of the ice near the divide of the main ice cap on Devon Island in the Canadian Arctic Archipelago. Temperature ranges from — 23.0°C at a depth of 20 m to — 18.4°C at the bottom. The difference between surface and bottom temperatures is about 1.5 deg less than expected for a steady state. Recent climatic warming seems the most likely explanation of the discrepancy. The temperature gradient in the lowest 50 m is approximately linear and corresponds to a geothermal heal flux of 1.5 h.f.u. This value may be invalid, however, because temperatures at and below this depth have probably been perturbed by changes of surface temperature during the past several thousand years, particularly by the warming at the end of the last glaciation. A detailed analysis of the results is in progress.

scholarly journals Reports on Current Work Temperatures in the Devon Island Ice Cap, Arctic Canada

1976 ◽  
Vol 16 (74) ◽  
pp. 277-277
Author(s):  
W.S.B. Paterson
Keyword(s):  
Steady State ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Climatic Warming ◽  
Devon Island ◽  
The Past ◽  
Ice Cap ◽  
Last Glaciation ◽  
Temperature Ranges ◽  
The Difference

AbstractTemperatures have been measured in a 299 m bore hole that reaches the base of the ice near the divide of the main ice cap on Devon Island in the Canadian Arctic Archipelago. Temperature ranges from — 23.0°C at a depth of 20 m to — 18.4°C at the bottom. The difference between surface and bottom temperatures is about 1.5 deg less than expected for a steady state. Recent climatic warming seems the most likely explanation of the discrepancy. The temperature gradient in the lowest 50 m is approximately linear and corresponds to a geothermal heal flux of 1.5 h.f.u. This value may be invalid, however, because temperatures at and below this depth have probably been perturbed by changes of surface temperature during the past several thousand years, particularly by the warming at the end of the last glaciation. A detailed analysis of the results is in progress.

CONSTRAINING LATEST HOLOCENE EXPANSION AND 20TH CENTURY RETREAT OF A SMALL CANADIAN ARCTIC ICE CAP USING ENTOMBED VEGETATION

2016 ◽  
Author(s):  
Simon L. Pendleton ◽  
◽  
Gifford H. Miller ◽  
Robert S. Anderson ◽  
Sarah E. Crump
Keyword(s):  
20Th Century ◽  
Canadian Arctic ◽  
Ice Cap ◽  
Arctic Ice

Comparison of 105 Years of Oxygen Isotope and Insoluble Impurity Profiles from the Devon Island and Camp Century Ice Cores

1979 ◽  
Vol 11 (3) ◽  
pp. 299-305 ◽  
Author(s):  
David A. Fisher
Keyword(s):  
Oxygen Isotope ◽  
Flow Line ◽  
Ice Cores ◽  
Devon Island ◽  
Ice Cap ◽  
Particulate Concentration ◽  
The Difference ◽  
Impurity Profiles ◽  
Level Lowering ◽  
Present Site

Oxygen-isotope profiles for the Devon Island ice cap and Camp Century Greenland are affected by a number of variables, some of which must have been the same for both sites. The two δ(18O) records spanning about 120,000 years are brought into relative alignment by comparison of major δ features, and subsequent verification that the insoluble particulate concentration records were also in phase for this alignment. The difference between the δ profiles is shown to be mainly a function of the altitude of the accumulation area for Camp Century. This altitude seems to have been higher than present for the last 100,000 years, suggesting the present flow line through the site has never been shorter. The maximum altitude for the Camp Century accumulation area is 1500 m above the present site and is almost synchronous with the maximum in particulate concentration that occurs at 16,000 yr B.P. The synchronism is likely due to the maximum sea-level lowering that exposed vast areas of continental shelf to wind erosion.

scholarly journals Cirriform Rotor Cloud Observed on a Canadian Arctic Ice Cap

1998 ◽  
Vol 126 (6) ◽  
pp. 1741-1745 ◽  
Author(s):  
Hisashi Ozawa ◽  
Kumiko Goto-Azuma ◽  
Koyuru Iwanami ◽  
Roy M. Koerner
Keyword(s):  
Canadian Arctic ◽  
Ice Cap ◽  
Arctic Ice

scholarly journals Natural and anthropogenic levels of tritium in a Canadian Arctic ice core, Agassiz Ice Cap, Ellesmere Island, and comparison with other radionuclides

2000 ◽  
Vol 46 (152) ◽  
pp. 35-40 ◽  
Author(s):  
Thomas G. Kotzer ◽  
Akira Kudo ◽  
James Zheng ◽  
Wayne Workman
Keyword(s):  
Ice Core ◽  
Canadian Arctic ◽  
Fission Products ◽  
Ellesmere Island ◽  
Anthropogenic Radionuclides ◽  
Ice Caps ◽  
Nuclear Bomb ◽  
Ice Cap ◽  
Nuclear Weapons Testing ◽  
Arctic Ice

AbstractNumerous studies of the ice caps in Greenland and Antarctica have observed accumulations of transuranic radionuclides and fission products from nuclear weapons testing, particularly during the period 1945–75. Recently, the concentrations of radionuclides in the annually deposited surface layers of Agassiz Ice Cap, Ellesmere Island, Canadian Arctic, from 1945 to the present have been measured and have demonstrated a continuous record of deposition of 137Cs and 239,240Pu in ice and snow. In this study, 3He-ingrowth mass spectrometry has been used to measure the low levels of tritium (3H) in some of these samples. Pre-nuclear-bomb tritium levels in ice-core samples were approximately 12 TU in high-latitude meteoric waters and 3–9 TU in mid-latitude meteoric waters. Comparisons of 3H levels and 3H/137Cs + 239,240Pu ratios, which were quite low during the earliest fission-bomb detonations (1946–51) and substantially higher during thermonuclear hydrogen-fusion bomb testing (1952–64), provide a clear indication of the type of nuclear device detonated. This finding accords with the results from other ice-core studies of the distribution of anthropogenic radionuclides from bomb fallout.

Landscapes of cold-centred Late Wisconsinan ice caps, Arctic Canada

1993 ◽  
Vol 17 (2) ◽  
pp. 223-247 ◽  
Author(s):  
Arthur S. Dyke
Keyword(s):  
Canadian Arctic ◽  
Thermal Conditions ◽  
Flow Patterns ◽  
Flow Conditions ◽  
Ice Flow ◽  
Zone Width ◽  
Ice Caps ◽  
Ice Cap ◽  
Late Wisconsinan ◽  
Subglacial Meltwater

Uplands of the Canadian Arctic Islands supported Late Wisconsinan ice caps that developed two landscape zones reflecting basal thermal conditions regulated by long-sustained ice flow patterns. Central cold-based zones protected older glacial and preglacial landscapes while peripheral warm-based zones scoured and otherwise altered their beds. Some geomorphic effects are independent of ice cap scale, others vary with scale. For ice caps of 30 km radius or more, scour-zone width remains proportionally constant to flowline length under similar flow conditions. But intensity of scouring, ice moulding of drift and rock eminences, size and abundance of subglacial meltwater features, and development of end moraines increase with ice cap size. Ice caps became entirely cold based early in retreat as the boundary between warm and cold ice shifted outward, probably because ice thinned and flow slackened. The frozen margins deflected meltwater, thus maximizing formation of lateral meltwater channels throughout retreat. The landform record of cold-based glaciers in this region is easily interpreted. Hence, regional ice sheet models invoking or based on the premise that cold-based ice leaves no geomorphic record seem untenable.

scholarly journals Holocene paleoenvironmental reconstruction from deep ground temperatures: a comparison with paleoclimate derived from the δ18O record in an ice core from the agassiz Ice Cap, Canadian Arctic Archipelago

1991 ◽  
Vol 37 (126) ◽  
pp. 209-219 ◽  
Author(s):  
Alan E. Taylor
Keyword(s):  
Surface Temperature ◽  
Snow Cover ◽  
Ice Core ◽  
Canadian Arctic ◽  
Ground Surface ◽  
Temperature Profiles ◽  
Canadian Arctic Archipelago ◽  
Ground Surface Temperature ◽  
Ice Cap ◽  
Surface Temperatures

Abstract Changes in ground-surface temperature for the past few hundred years have been derived from deep temperature profiles at three wells in the northeastern Canadian Arctic Archipelago, and compared with the climatic history derived from the oxygen-isotope ratio 18O/16O measured in an ice core from the Agassiz Ice Cap, about 180-260 km to the east. Analysis of the ground-temperature profiles suggests that surface temperatures in the area decreased after the Little Climatic Optimum about 1000 years ago until the Little Ice Age (LIA). About 100 years ago, ground-surface temperatures appear to have increased by 2-5K to reach today’s values, while air temperatures increased by 2-3K, according to the isotope record. Part of the larger ground-surface temperature change may be due to other paleoenvironmental effects, such as an increase in snow cover coincident with the end of the LIA. The δ18O climatic record was successful in predicting the general features of the ground-temperature profiles observed at two of the sites, but not the third. There is contemporary evidence that surface temperatures at the latter site may be substantially modified by other environmental factors such as snow cover.

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