The Ross Ice Shelf Project

Clough, John W.; Hansen, B. Lyle

doi:10.1126/science.203.4379.433

Cited by 96 publications

(59 citation statements)

References 16 publications

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“…Figure 13 shows the comparison between computed and observed temperature-depth profiles at the two locations, J9 and Little America V (LA V), where bore holes have completely penetrated the ice shelf (Crary, 1961;Clough and Hansen, 1979). We remark that some discrepancy in this comparison is inevitable because.…”

Section: Comparison With Observationsmentioning

confidence: 99%

“…The first method is difficult because it requires ice drilling or electrical resistivity profiling (Shabtaie and Bentley, 1979). Local surveys are possible (Clough and Hansen, 1979;Shabtaie and Bentley, 1979) but they are most useful for verification of precisely defined regions of basal melting. The second method is attempted in this study using observations made during the Ross Ice Shelf Glaciological and Geophysical Survey (RIGGS) and other field programs (Zumberge, 1964;Bentley and others, 1979;Thomas and others, 1984).…”

Section: Zusammenfassung Die Wirkung Des Schmelzens An Dermentioning

confidence: 99%

“…13. The observed and simulated temperature-depth profiles at J9 and Lillle America V are plolled for comparison ( Crary , 1961;Clough and Hansen , 1979).…”

Section: Comparison With Observationsmentioning

confidence: 99%

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The Effects of Basal Melting on the Present Flow of the Ross Ice Shelf, Antarctica

MacAyeal

Thomas

1986

J. Glaciol.

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ABSTRACT. We use a hybrid finite-element / finitedifference model of ice-shelf flow and heat transfer to investigate the effects of basal melting on the present observed flow of the Ross Ice Shelf. Two hypothetical basal melting scenarios are compared: (i) zero melting everywhere and (ii) melting sufficient to balance any large-scale patterns of ice-shelf thickening that would otherwise occur. As a result of the temperature-dependent flow law (which we idealize as having a constant activation energy of 120 kJ mori, a scaling coefficient of 1.3 N m-2 sl/3, and an exponent of 3), simulated ice-shelf velocities for the second scenario are reduced by up to 20% below those of the first. Our results support the hypothesis that melting patterns presently maintain ice thickness in steady state and conform to patterns of oceanic circulation presently thought to ventilate the sub-ice cavity. Differences between the simulated and observed velocities are too large in the extreme south-eastern quarter of the ice shelf to permit verification of either basal melting scenario . These differences highlight the need to improve model boundary conditions at points where ice streams feed the ice shelf and where the ice shelf meets stagnant grounded ice .

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Section: Comparison With Observationsmentioning

confidence: 99%

Section: Zusammenfassung Die Wirkung Des Schmelzens An Dermentioning

confidence: 99%

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The Effects of Basal Melting on the Present Flow of the Ross Ice Shelf, Antarctica

MacAyeal

Thomas

1986

J. Glaciol.

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“…7). We adopt a uniform value of a Z calculated from the observed temperature-depth profile at J 9 (Clough and Hansen, 1979), and regard the effect of regional temperature variation as uncertainty.…”

Section: Flow Lawmentioning

confidence: 99%

Force, Mass, and Energy Budgets of the Crary Ice Rise Complex, Antarctica

Macayeal¹,

Bindschadler²,

Shabtaie³

et al. 1987

J. Glaciol.

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ABSTRACT. Resistive force exerted by the Crary Ice Rise on its ice-shelf/ice-stream environment and backpressure force transmitted across the grounding lines of Ice Streams A and B are calculated from airborne radio echo-sounding data and measurements of surface strain-rates. Resistance generated by the ice rise ranges in magnitude between 45 and 51% of the back-pressure force on the ice streams (depending on the flow law). The mechanical-energy budget of the ice rise is computed by considering work done against frictional forces at the perimeter of the ice rise and gravitational potential energy fluxes associated with changing mass distribution in the ice/ocean system. Energy dissipated by flow surrounding the ice rise is balanced by potential energy released within Ice Streams A and B, and accounts for between 15 and 49% of the work done by the ice streams against ice-shelf back pressure at their grounding lines. Mass balance of the ice rise, and the discharge of Ice Streams A and B, are calculated from surface-velocity and snow-accumulation measurements. The ice rise and its immediate environment gain mass by advection and snowfall at a rate equivalent to an area-averaged thickening rate of 0.44 ± 0.06 m/year. This mass gain may be balanced by regional basal melting (which we do not measure), or could contribute to ice-rise expansion through regional thickening and ice-shelf grounding. Approximately 1/4 to 1/2 of the excess volume discharged by Ice Streams A and B above snow accumulation in their catchment areas is deposited in the vicinity of the ice rise (or melted from the bottom of the ice shelf). This suggests that the ice rise may have formed as a consequence of recent ice-stream acceleration, and that its continued growth may eventually reverse this trend of ice-stream discharge.

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“…Such information has been lacking to date. Sediment cores collected from beneath the Ross (Clough & Hansen 1979) and the Novolazarevskiy (Kolobov & Savatyugin 1983) ice shelves have not yielded any Holocene sediment, reflecting the low penetration of open shelf water currents to these sites.…”

Section: Introductionmentioning

confidence: 99%

History of benthic colonisation beneath the Amery Ice Shelf, East Antarctica

Post¹,

Hemer²,

O'Brien³

et al. 2007

Mar. Ecol. Prog. Ser.

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This study presents compelling evidence for a diverse and abundant seabed community that developed over the course of the Holocene beneath the Amery Ice Shelf, East Antarctica. Fossil analysis of a 47 cm long sediment core revealed a rich modern fauna dominated by filter feeders (sponges and bryozoans). The down-core assemblage indicated a succession in the colonisation of this site. The lower portion of the core (before ~9600 yr BP) was completely devoid of preserved fauna. The first colonisers (at ~10 200 yr BP) were mobile benthic organisms. Their occurrence was matched by the first appearance of planktonic taxa, indicating a retreat of the ice shelf following the last glaciation to within sufficient distance to advect planktonic particles via bottom currents. The benthic infauna and filter feeders emerged during the peak abundance of the planktonic organisms, indicating their dependence on the food supply sourced from the open shelf waters of Prydz Bay. Understanding patterns of species succession in this environment has important implications for determining the potential significance of future ice shelf collapse.

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The Ross Ice Shelf Project

Cited by 96 publications

References 16 publications

The Effects of Basal Melting on the Present Flow of the Ross Ice Shelf, Antarctica

The Effects of Basal Melting on the Present Flow of the Ross Ice Shelf, Antarctica

Force, Mass, and Energy Budgets of the Crary Ice Rise Complex, Antarctica

History of benthic colonisation beneath the Amery Ice Shelf, East Antarctica

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