scholarly journals Growth and Grounding of the Ellesmere Island Ice Rises

1972 ◽  
Vol 11 (61) ◽  
pp. 43-52 ◽  
Author(s):  
John B. Lyons ◽  
R. H. Ragle ◽  
A. J. Tamburi
Keyword(s):  
Heat Conduction ◽  
Heat Flow ◽  
Ellesmere Island ◽  
Ice Shelf ◽  
Sea Floor ◽  
The Past ◽  
Conduction Theory

AbstractAnalysis of glaciologial data indicates that grounding of the Ward Hunt Ice Shelf and its conversion into an ice rise was primarily the result of local thickening of a floating ice shelf and the availability of a very gently sloping sea floor on which the ice shelf came to rest. Application of heat conduction theory to a series of thermal profiles through the Ward Hunt Ice Shelf, and the Ward Hunt, Camp Creek and Cape Discovery ice rises shows that present heat flow in this area of northern Ellesmere Island is more than twice normal, and that the outer and intermediate parts of the Ward Hunt ice rise grounded 250–350 years ago, during a cycle of climatic deterioration. Development and localization of ice rises along northern Ellesmere Island are strongly influenced by topography, and all ice rises we have studied seem to have formed within the past 1 600 years, possibly with major growth in the interval from 1 000 to 150 years ago.

scholarly journals Growth and Grounding of the Ellesmere Island Ice Rises

1972 ◽  
Vol 11 (61) ◽  
pp. 43-52 ◽  
Author(s):  
John B. Lyons ◽  
R. H. Ragle ◽  
A. J. Tamburi
Keyword(s):  
Heat Conduction ◽  
Heat Flow ◽  
Ellesmere Island ◽  
Ice Shelf ◽  
Sea Floor ◽  
The Past ◽  
Conduction Theory

AbstractAnalysis of glaciologial data indicates that grounding of the Ward Hunt Ice Shelf and its conversion into an ice rise was primarily the result of local thickening of a floating ice shelf and the availability of a very gently sloping sea floor on which the ice shelf came to rest. Application of heat conduction theory to a series of thermal profiles through the Ward Hunt Ice Shelf, and the Ward Hunt, Camp Creek and Cape Discovery ice rises shows that present heat flow in this area of northern Ellesmere Island is more than twice normal, and that the outer and intermediate parts of the Ward Hunt ice rise grounded 250–350 years ago, during a cycle of climatic deterioration. Development and localization of ice rises along northern Ellesmere Island are strongly influenced by topography, and all ice rises we have studied seem to have formed within the past 1 600 years, possibly with major growth in the interval from 1 000 to 150 years ago.

scholarly journals Movement of the Ward Hunt Ice Shelf, Ellesmere Island, N.W.T., Canada

1971 ◽  
Vol 10 (59) ◽  
pp. 211-225 ◽  
Author(s):  
E. Dorrer
Keyword(s):  
Power Flow ◽  
Field Work ◽  
Ellesmere Island ◽  
Ice Shelf ◽  
Surface Layers ◽  
Atmospheric Refraction ◽  
Near Surface ◽  
Angle Measurements ◽  
Ice Velocity ◽  
Ice Forces

AbstractThe movement at a marginal location on the Ward Hunt Ice Shelf, northern Ellesmere Island, was determined by repeated survey measurements with theodolite and geodimeter. The purpose and duration of the field work, and reduction of the observational data are described, and the resulting mean ice velocity of 0.53 m year-1is discussed. Strain-rates of a 1 km by 1 km deformation figure are determined. The parametersnandBof Glen’s power flow law are determined by using the equations given by Nye and Weertman. The results are compared with experimental data. Computed ice stresses show that the “ridge-and-trough" structure on the ice shelf surface is not originated by internal ice forces. The elevations of all survey markers have been determined from vertical-angle measurements, and the peculiarities of atmospheric refraction in near-surface layers are discussed.

scholarly journals Universality in heat conduction theory: weakly nonlocal thermodynamics

2012 ◽  
Vol 524 (8) ◽  
pp. 470-478 ◽  
Author(s):  
P. Ván ◽  
T. Fülöp
Keyword(s):  
Heat Conduction ◽  
Conduction Theory

Seasonal deposition of phytodetritus to the deep-sea floor

1986 ◽  
Vol 88 ◽  
pp. 265-279 ◽  
Author(s):  
A. L. Rice ◽  
D. S. M. Billett ◽  
J. Fry ◽  
A. W. G. John ◽  
R. S. Lampitt ◽  
...  
Keyword(s):  
Deep Sea ◽  
Benthic Communities ◽  
Time Lapse ◽  
Sediment Traps ◽  
Temporal Variations ◽  
Sea Floor ◽  
Porcupine Seabight ◽  
The Past ◽  
Sea Bed ◽  
Seasonal Deposition

SynopsisEvidence has accumulated over the past twenty years to suggest that the deep-sea environment is not as constant as was at one time thought, but exhibits temporal variations related to the seasonally in the overlying surface waters. Recent results from deep-moored sediment traps suggest that this coupling is mediated through the sedimentation of organic material, while observations in the Porcupine Seabight indicate that in this region, at least, there is a major and rapid seasonal deposition of aggregated phytodetritus to the sea-floor at slope and abyssal depths.This paper summarises the results of the Porcupine Seabight studies over the past five years or so, using time-lapse sea-bed photography and microscopic, microbiological and chemical analyses of samples of phytodetritus and of the underlying sediment. The data are to some extent equivocal, but they suggest that the seasonal deposition is a regular and dramatic phenomenon and that the material undergoes relatively little degradation during its passage through the water column. The mechanisms leading to the aggregation of the phytodetritus have not been identified, and it is not yet known whether the phenomenon is geographically widespread nor whether it is of significance to the deep-living mid-water and benthic communities.

scholarly journals Sources And Movement of Icebergs in the South-West Ross Sea, Antarctica

1989 ◽  
Vol 12 ◽  
pp. 85-88 ◽  
Author(s):  
Harry Keys ◽  
Dennis Fowler
Keyword(s):  
Small Proportion ◽  
Ross Sea ◽  
The South ◽  
Ice Shelf ◽  
Sea Floor ◽  
Ross Ice Shelf ◽  
South West ◽  
Fast Ice ◽  
Western Side ◽  
Coastal Strip

The shape, surface features, composition, and thickness of icebergs trapped annually in a 200 km long coastal strip of fast ice have been examined to determine their sources and movement. The thin western ice front of the Ross Ice Shelf seems to produce about 40% of the icebergs while local glaciers produce the remainder. The ice-shelf icebergs are carried west towards Ross Island then north up the western side of the Ross Sea. A small proportion of them gets trapped mainly by grounding on shallow areas of the sea floor which protrude across the regional long-shore currents.

scholarly journals Volume and area changes of the Milne Ice Shelf, Ellesmere Island, Nunavut, Canada, since 1950

2012 ◽  
Vol 117 (F4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Colleen A. Mortimer ◽  
Luke Copland ◽  
Derek R. Mueller
Keyword(s):  
Ellesmere Island ◽  
Ice Shelf

scholarly journals An improved bathymetry compilation for the Bellingshausen Sea, Antarctica, to inform ice-sheet and ocean models

2010 ◽  
Vol 4 (4) ◽  
pp. 2079-2101 ◽  
Author(s):  
A. G. C. Graham ◽  
F. O. Nitsche ◽  
R. D. Larter
Keyword(s):  
Ocean Circulation ◽  
Ice Sheet ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ice Shelves ◽  
Sea Floor ◽  
Bellingshausen Sea ◽  
Warm Deep Water ◽  
Basal Melting

Abstract. The southern Bellingshausen Sea (SBS) is a rapidly-changing part of West Antarctica, where oceanic and atmospheric warming has led to the recent basal melting and break-up of the Wilkins ice shelf, the dynamic thinning of fringing glaciers, and sea-ice reduction. Accurate sea-floor morphology is vital for understanding the continued effects of each process upon changes within Antarctica's ice sheets. Here we present a new bathymetric grid for the SBS compiled from shipborne echo-sounder, spot-sounding and sub-ice measurements. The 1-km grid is the most detailed compilation for the SBS to-date, revealing large cross-shelf troughs, shallow banks, and deep inner-shelf basins that continue inland of coastal ice shelves. The troughs now serve as pathways which allow warm deep water to access the ice fronts in the SBS. Our dataset highlights areas still lacking bathymetric constraint, as well as regions for further investigation, including the likely routes of palaeo-ice streams. The new compilation is a major improvement upon previous grids and will be a key dataset for incorporating into simulations of ocean circulation, ice-sheet change and history. It will also serve forecasts of ice stability and future sea-level contributions from ice loss in West Antarctica, required for the next IPCC assessment report in 2013.

Radiogenic Isotope Signatures of Holocene Sediments from Kane Basin: Linkage with the Re-opening and Evolution of Nares Strait

2021 ◽  
Author(s):  
Lina Madaj ◽  
Friedrich Lucassen ◽  
Claude Hillaire-Marcel ◽  
Simone A. Kasemann
Keyword(s):  
Ellesmere Island ◽  
The Arctic ◽  
Baffin Bay ◽  
Low Salinity ◽  
The Core ◽  
The Past ◽  
Nares Strait ◽  
The North ◽  
Sediment Input ◽  
Detrital Sediment

<p>The re-opening of the Arctic Ocean-Baffin Bay gateway through Nares Strait, following the Last Glacial Maximum, has been partly documented, discussed and revised in the past decades. The Nares Strait opening has led to the inception of the modern fast circulation pattern carrying low-salinity Arctic water towards Baffin Bay and further towards the Labrador Sea. This low-salinity water impacts thermohaline conditions in the North Atlantic, thus the Atlantic Meridional Overturning Circulation. Available land-based and marine records set the complete opening between 9 and 7.5 ka BP [1-2], although the precise timing and intensification of the southward flowing currents is still open to debate. A recent study of a marine deglacial sedimentary record from Kane Basin, central Nares Strait, adds information about subsequent paleoceanographic conditions in this widened sector of the strait and proposed the complete opening at ~8.3 ka BP [3].</p><p>We present complementary radiogenic strontium, neodymium and lead isotope data of the siliciclastic detrital sediment fraction of this very record [3] further documenting the timing and pattern of Nares Strait opening from a sediment provenance approach. The data permit to distinguish detrital material from northern Greenland and Ellesmere Island, transported to the core location from both sides of Nares Strait. Throughout the Holocene, the evolution of contributions of these two sources hint to the timing of the ice break-up in Kennedy Channel, north of Kane Basin, which led to the complete opening of Nares Strait [3]. The newly established gateway of material transported to the core location from the north via Kennedy Channel is recorded by increased contribution of northern Ellesmere Island detrital sediment input. This shift from a Greenland (Inglefield Land) dominated sediment input to a northern Ellesmere Island dominated sediment input supports the hypothesis of the newly proposed timing of the complete opening of Nares Strait at 8.3 ka BP [3] and highlights a progressive trend towards modern-like conditions, reached at about 4 ka BP.</p><p>References:</p><p>[1] England (1999) Quaternary Science Reviews, 18(3), 421–456. [2] Jennings et al. (2011) Oceanography, 24(3), 26-41. [3] Georgiadis et al. (2018) Climate of the Past, 14 (12), 1991-2010.</p>

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