New Light on the Mode of Uplift of the Fish and Fossiliferous Moraines of the Mcmurdo Ice Shelf, Antarctica

1965 ◽  
Vol 5 (42) ◽  
pp. 813-828 ◽  
Author(s):  
A. J. Gow ◽  
W. F. Weeks ◽  
G. Hendrickson ◽  
R. Rowland
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Marine Invertebrate ◽  
Lower Surface ◽  
Faunal Remains ◽  
Ice Shelf ◽  
Water Ice ◽  
Deep Diving ◽  
Ice Surface ◽  
Fish Remains

Abstract The McMurdo Ice Shelf and associated faunal remains were examined in the vicinity of the easternmost Dailey Island. Stratigraphic, petrographic, and chemical composition studies of cores from two holes drilled through the ice shelf show that at these locations the shelf is composed only of fresh-water ice. Although cores from the deeper hole possessed typically glacial textures throughout, much of the ice from this part of the McMurdo Ice Shelf may have been formed from the freezing of a layer of fresh water found sandwiched between shelf bottom and the underlying sea-water. The existence of fresh water under the ice shelf can most probably be attributed to drainage of surface melt water during the ablation season. There was no evidence to indicate that this part of the McMurdo Ice Shelf is being nourished by the growth of sea ice onto its lower surface. The fish remains found on the ice surface were confined to a narrow zone along the tide crack and are believed to have been left in this vicinity by deep diving seals. The marine invertebrate remains on top of the ice are associated with morainal material and are believed to have been incorporated into the ice at the time of formation of the moraines.

New Light on the Mode of Uplift of the Fish and Fossiliferous Moraines of the Mcmurdo Ice Shelf, Antarctica

1965 ◽  
Vol 5 (42) ◽  
pp. 813-828 ◽  
Author(s):  
A. J. Gow ◽  
W. F. Weeks ◽  
G. Hendrickson ◽  
R. Rowland
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Marine Invertebrate ◽  
Lower Surface ◽  
Faunal Remains ◽  
Ice Shelf ◽  
Water Ice ◽  
Deep Diving ◽  
Ice Surface ◽  
Fish Remains

AbstractThe McMurdo Ice Shelf and associated faunal remains were examined in the vicinity of the easternmost Dailey Island. Stratigraphic, petrographic, and chemical composition studies of cores from two holes drilled through the ice shelf show that at these locations the shelf is composed only of fresh-water ice. Although cores from the deeper hole possessed typically glacial textures throughout, much of the ice from this part of the McMurdo Ice Shelf may have been formed from the freezing of a layer of fresh water found sandwiched between shelf bottom and the underlying sea-water. The existence of fresh water under the ice shelf can most probably be attributed to drainage of surface melt water during the ablation season. There was no evidence to indicate that this part of the McMurdo Ice Shelf is being nourished by the growth of sea ice onto its lower surface. The fish remains found on the ice surface were confined to a narrow zone along the tide crack and are believed to have been left in this vicinity by deep diving seals. The marine invertebrate remains on top of the ice are associated with morainal material and are believed to have been incorporated into the ice at the time of formation of the moraines.

scholarly journals Water Circulation and Ice Accretion Beneath Ward Hunt Ice Shelf (Northern Ellesmere Island, Canada), Deduced From Salinity and Isotope Analysis of Ice Cores

1988 ◽  
Vol 10 ◽  
pp. 68-72 ◽  
Author(s):  
Martin O. Jeffries ◽  
William M. Sackinger ◽  
H. Roy Krouse ◽  
Harold V. Serson
Keyword(s):  
Sea Ice ◽  
Fresh Water ◽  
Sea Water ◽  
Ice Core ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Water Circulation ◽  
Ice Shelf ◽  
The West ◽  
Water Ice

Ice-core drilling and ice-core analysis (electrical conductivity–salinity, 18O, 3H, density) reveal that the internal structure of the west Ward Hunt Ice Shelf contrasts sharply with that of the east ice shelf. The west ice shelf contains a great thickness (≥22 m) of sea ice (mean salinity, 2.22‰; mean δ18O, -0.8‰), whereas the east ice shelf is entirely of meteoric or fresh-water ice (mean salinity 0.01‰; mean δ18O, -29.7‰). High tritium activities are found only in ice from near the bottom of the east and west ice shelves. The contrasting ice-core data is considered to be a proxy record of variations in water circulation and bottom freezing beneath the ice shelf. The west shelf is underlain by sea water flowing into Disraeli Fiord. Sea ice accretes on to the bottom of the west ice shelf from the sea-water flowing into the fiord. Sea-water flowing out of the fiord is directed below the east ice shelf. However, the east ice shelf is not underlain directly by sea-water but by a layer of fresh water from the surface of Disraeli Fiord. In this region, ice growth resulting from the presence of this stable fresh-water layer has been accompanied by surface ablation over a period of perhaps the last 450 years. As a result, fresh-water ice has completely replaced any sea ice that originally grew in the region of the east ice shelf. Whereas the west and east shelves are underlain almost exclusively by sea-water and fresh water, ice in the south shelf is the result of freezing of fresh, brackish or sea water. This is attributed to mixing of the inflowing and outflowing waters.

scholarly journals Water Circulation and Ice Accretion Beneath Ward Hunt Ice Shelf (Northern Ellesmere Island, Canada), Deduced From Salinity and Isotope Analysis of Ice Cores

1988 ◽  
Vol 10 ◽  
pp. 68-72 ◽  
Author(s):  
Martin O. Jeffries ◽  
William M. Sackinger ◽  
H. Roy Krouse ◽  
Harold V. Serson
Keyword(s):  
Sea Ice ◽  
Fresh Water ◽  
Sea Water ◽  
Ice Core ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Water Circulation ◽  
Ice Shelf ◽  
The West ◽  
Water Ice

Ice-core drilling and ice-core analysis (electrical conductivity–salinity, 18O, 3H, density) reveal that the internal structure of the west Ward Hunt Ice Shelf contrasts sharply with that of the east ice shelf. The west ice shelf contains a great thickness (≥22 m) of sea ice (mean salinity, 2.22‰; mean δ18O, -0.8‰), whereas the east ice shelf is entirely of meteoric or fresh-water ice (mean salinity 0.01‰; mean δ18O, -29.7‰). High tritium activities are found only in ice from near the bottom of the east and west ice shelves. The contrasting ice-core data is considered to be a proxy record of variations in water circulation and bottom freezing beneath the ice shelf. The west shelf is underlain by sea water flowing into Disraeli Fiord. Sea ice accretes on to the bottom of the west ice shelf from the sea-water flowing into the fiord. Sea-water flowing out of the fiord is directed below the east ice shelf. However, the east ice shelf is not underlain directly by sea-water but by a layer of fresh water from the surface of Disraeli Fiord. In this region, ice growth resulting from the presence of this stable fresh-water layer has been accompanied by surface ablation over a period of perhaps the last 450 years. As a result, fresh-water ice has completely replaced any sea ice that originally grew in the region of the east ice shelf. Whereas the west and east shelves are underlain almost exclusively by sea-water and fresh water, ice in the south shelf is the result of freezing of fresh, brackish or sea water. This is attributed to mixing of the inflowing and outflowing waters.

scholarly journals Melting of fresh-water ice in sea water

1962 ◽  
Vol 4 (31) ◽  
pp. 134 ◽  
Author(s):  
F. Loewe
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Water Ice

scholarly journals Stratigraphy, stable isotopes and salinity in multi-year sea ice from the rift area, south George VI Ice Shelf, Antarctic Peninsula

1991 ◽  
Vol 37 (127) ◽  
pp. 357-367
Author(s):  
J.-L. Tison ◽  
E. M. Morris ◽  
R. Souchez ◽  
J. Jouzel
Keyword(s):  
Stable Isotopes ◽  
Sea Ice ◽  
Fresh Water ◽  
Large Scale ◽  
Sea Water ◽  
Ice Core ◽  
Ice Shelf ◽  
The Core ◽  
Brackish Ice ◽  
Ice Production

AbstractResults from a detailed profile in a 5.54 m multi-year sea-ice core from the rift area in the southern part of George VI Ice Shelf are presented. Stratigraphy, stable isotopes and Na content are used to investigate the growth processes of the ice cover and to relate them to melting processes at the bottom of the ice shelf.The thickest multi-year sea ice in the sampling area appears to be second-year sea ice that has survived one melt season. Combined salinity/stable-isotope analyses show large-scale sympathetic fluctuations that can be related to the origin of the parent water. Winter accretion represents half of the core length and mainly consists of frazil ice of normal sea-water origin. However, five major dilution events of sea water, with fresh-water input from the melting base of the ice shelf reaching 20% on two occasions, punctuate this winter accretion. Two of them correspond to platelet-ice production, which is often related to the freezing of ascending supercooled water from the bottom of the ice shelf.Brackish ice occurs between 450 and 530 cm in the core. It is demonstrated that this results from the freezing of brackish water (Jeffries and others, 1989) formed by mixing of normal sea water with melted basal shelf ice, with dilution percentages of maximum 80% fresh water.

scholarly journals On Melting of Fresh-Water Ice In Sea-Water

1961 ◽  
Vol 3 (30) ◽  
pp. 1051-1052
Author(s):  
F. Loewe
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Ice Sheets ◽  
Ice Shelves ◽  
Water Ice

AbstractMelting at the bottom of floating ice shelves may represent an important item in the mass economy of ice sheets. Some earlier studies of the behaviour of fresh-water ice in sea-water at a temperature below 0° C. are quoted.

scholarly journals II. Ice observations

1859 ◽  
Vol 9 ◽  
pp. 609-611 ◽  
Keyword(s):  
Specific Gravity ◽  
Sea Ice ◽  
Fresh Water ◽  
Sea Water ◽  
Water Ice ◽  
Rate Of Growth ◽  
Abundant Evidence ◽  
Domestic Use ◽  
The Subject ◽  
Original Water

The contradictory statements of Dr. Sutherland and Dr. Kane, with regard to the saltness of the ice formed from sea-water,—the former maintaining that sea-water ice contains about one-fourth of the salt of the original water; the latter, that if the cold be sufficiently intense, there will be formed from sea-water a fresh and purer element fit for domestic use,—induced the author to take advantage of his position, as naturalist to the expedition now in the northern seas, to reinvestigate the subject. The changes which he has observed sea-water to undergo in freezing are the following. When the temperature falls below + 28°⋅5, it becomes covered with a thin pellicle of ice; after some time this pellicle becomes thicker and presents a vertically striated structure, similar to that of the ordinary cakes of sal-ammoniac. As the ice further increases in thickness, it becomes more compact, but the lowest portion still retains the striated structure. On the surface of the ice, saline crystals, designated by the author “efflorescence,” soon begin to form, at first few in number and widely separated, but gradually forming into tufts and ultimately covering the whole surface. At first, the increase in thickness of the ice is rapid, but afterwards the rate of growth is much slower and more uniform. The ice formed yields, on being melted, a solution differing in specific gravity according to the temperature at the time of congelation, its density being less, the lower the temperature at which the process of congelation took place. Although the author’s observations extended from + 28°⋅5 to —42°, he was never able to obtain fresh-water from sea-ice, the purest specimen being of specific gravity 1⋅005, and affording abundant evidence of the presence of salts, especially of chloride of sodium, in such quantity as to render it unfit for domestic purposes.

Measurement of thermal conduction within a large fresh water ice block being towed in sea water

1980 ◽  
Vol 1 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
W. Clifford ◽  
R. Erman ◽  
A. Fuhs ◽  
R. Stolfi
Keyword(s):  
Fresh Water ◽  
Thermal Conduction ◽  
Sea Water ◽  
Water Ice

scholarly journals An Ice-shelf Moraine, George VI Sound, Antarctica

1981 ◽  
Vol 2 ◽  
pp. 135-141 ◽  
Author(s):  
D. E. Sugden ◽  
C. M. Clapperton
Keyword(s):  
Conceptual Model ◽  
Fresh Water ◽  
Antarctic Peninsula ◽  
Sea Water ◽  
Ice Sheet ◽  
Ice Shelf ◽  
Western Margin ◽  
Grounding Line ◽  
Double Ridge

The morphology, sediments, and processes associated with the construction of a moraine along the western margin of the ice shelf in George VI Sound, Antarctica, are discussed. The moraine occurs as a double ridge where the ice sheet grounds against promontories on Alexander Island and is approximately horizontal over a distance of 120 km. It consists of exotic rock debris carried into the ice shelf by Antarctic Peninsula glaciers and local rock debris derived from the grounding line on Alexander Island. As the coast steepens, so the proportion of exotic rocks increases. The transport of basal material from the peninsula implies that there can be little bottom melting beneath this part of the ice shelf. The moraine is modified by streams and marginal lakes which periodically drain into and through the ice shelf. Tidal lakes are impounded against the ice shelf in shallower embayments and consist of fresh water overlying sea-water. A conceptual model of the moraine is developed and may help to explain some features of puzzling horizontal moraines found in formerly glaciated areas.

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