scholarly journals Ice Movement Studies on the Skelton Glacier

1961 ◽  
Vol 3 (29) ◽  
pp. 873-878 ◽  
Author(s):  
Charles R. Wilson ◽  
A. P. Crary
Keyword(s):  
Ross Sea ◽  
Ice Thickness ◽  
Strain Rates ◽  
Shelf Area ◽  
Dry Valleys ◽  
Ice Shelf ◽  
The West ◽  
Ross Ice Shelf ◽  
High Plateau ◽  
Plateau Area

The volume of ice that flows annually from the Skelton Glacier on the west side of the Ross Ice Shelf between the Worcester and Royal Society Ranges was determined during 1958–59 traverse operations to be approximately 791 × 106 m.3 or 712 × 106 m.3 water equivalent. Annual accumulation on the Skelton névé field and small cirque glaciers is estimated to be 1,018 × 106 m.3 water equivalent, but this figure can be reduced to 712 × 106 m.3 by assuming that 30 per cent of the expected accumulation in the lower slopes of the glacier is lost to adjacent areas of the Ross Ice Shelf by katabatic winds. It is evident that little or no contribution to the nourishment of the Skelton Glacier comes from the high plateau area of East Antarctica. It is suggested that this condition exists generally in the western Ross Sea and Ross Shelf area, and is responsible for the existence of the present “dry” valleys in the McMurdo Sound area. Some estimates of local ice regime are made at two sites on the glacier where ice thickness and strain rates are known.

scholarly journals Ice Movement Studies on the Skelton Glacier

1961 ◽  
Vol 3 (29) ◽  
pp. 873-878
Author(s):  
Charles R. Wilson ◽  
A. P. Crary
Keyword(s):  
Ross Sea ◽  
Ice Thickness ◽  
Strain Rates ◽  
Shelf Area ◽  
Dry Valleys ◽  
Ice Shelf ◽  
The West ◽  
Ross Ice Shelf ◽  
High Plateau ◽  
Plateau Area

The volume of ice that flows annually from the Skelton Glacier on the west side of the Ross Ice Shelf between the Worcester and Royal Society Ranges was determined during 1958–59 traverse operations to be approximately 791 × 106 m.3 or 712 × 106 m.3 water equivalent. Annual accumulation on the Skelton névé field and small cirque glaciers is estimated to be 1,018 × 106 m.3 water equivalent, but this figure can be reduced to 712 × 106 m.3 by assuming that 30 per cent of the expected accumulation in the lower slopes of the glacier is lost to adjacent areas of the Ross Ice Shelf by katabatic winds. It is evident that little or no contribution to the nourishment of the Skelton Glacier comes from the high plateau area of East Antarctica. It is suggested that this condition exists generally in the western Ross Sea and Ross Shelf area, and is responsible for the existence of the present “dry” valleys in the McMurdo Sound area.Some estimates of local ice regime are made at two sites on the glacier where ice thickness and strain rates are known.

The calving and drift of iceberg B-9 in the Ross Sea, Antarctica

1990 ◽  
Vol 2 (3) ◽  
pp. 243-257 ◽  
Author(s):  
Harry (J.R.) Keys ◽  
S.S. Jacobs ◽  
Don Barnett
Keyword(s):  
Ocean Circulation ◽  
Ross Sea ◽  
Maximum Velocity ◽  
Open Water ◽  
Ice Thickness ◽  
Ice Shelf ◽  
East Central ◽  
North West ◽  
Ross Ice Shelf ◽  
Subsurface Current

Major rifts is the Ross Ice Shelf controlled the October 1987 calving of the 154 × 35 km “B-9” iceberg, one of the longest on record. The 2000 km, 22 month drift of this iceberg and the quite different tracks of smaller bergs that calved with it have extended our understanding of the ocean circulation in the Ross Sea. B-9 initially moved north-west for seven months until deflected southward by a subsurface current which caused it to collide with the ice shelf in August 1988. It then completed a 100 km-radius gyre on the east-central shelf before resuming its north-westerly drift. Based upon weekly locations, derived from NOAA-10 and DMSP satellite and more frequent ARGOS data buoy positions, B-9 moved at an average speed of 2.4 km day−1 over the continental shelf. It was not grounded there at any time, but cast a large shadow of open water or reduced ice thickness during the austral winters. B-9 was captured by the continental slope current in May 1989, and attained a maximum velocity of 13 km day−1 before breaking into three pieces north of Cape Adare in early August 1989.

scholarly journals Field Studies of Bottom Crevasses in the Ross Ice Shelf, Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 341 ◽  
Author(s):  
Kenneth C. Jezek ◽  
Charles R. Bentley
Keyword(s):  
Bottom Topography ◽  
Field Studies ◽  
Airborne Radar ◽  
Ice Thickness ◽  
Ice Shelf ◽  
The West ◽  
West Antarctic Ice Sheet ◽  
Ross Ice Shelf ◽  
West Antarctic ◽  
Grounding Line

Surface and airborne radar sounding data were used to identify and map fields of bottom crevasses on the Ross Ice Shelf. Two major concentrations of crevasses were found, one along the grid-eastern grounding line and another, made up of eight smaller sites, grid-west of Crary Ice Rise. Based upon an analysis of bottom crevasse heights and locations, and of the strength of radar waves diffracted from the apex and bottom corners of the gridcrevasses, we conclude that the crevasses are formed at discrete locations on the ice shelf. By comparing the locations of crevasse formation with ice thickness and bottom topography, we conclude that most of the crevasse sites are associated with grounding. Hence we have postulated that six grounded areas, in addition to Crary Ice Rise and Roosevelt Island, exist in the grid-western sector of the ice shelf. These pinning points may be important for interpreting the dynamics of the West Antarctic ice sheet.

Tides of the Ross Sea and Ross Ice Shelf cavity

2003 ◽  
Vol 15 (1) ◽  
pp. 31-40 ◽  
Author(s):  
LAURENCE PADMAN ◽  
SVETLANA EROFEEVA ◽  
IAN JOUGHIN
Keyword(s):  
Ross Sea ◽  
Spring Tide ◽  
Model Performance ◽  
Tidal Currents ◽  
Tidal Range ◽  
Ocean Tide ◽  
Shelf Area ◽  
Ice Shelf ◽  
Ross Ice Shelf ◽  
Ocean Tide Models

Two new ocean tide models for the Ross Sea including the ocean cavity under the Ross Ice Shelf, are described. The optimum model for predicting ice shelf surface height variability is based on assimilation of gravimetry-derived tidal constituents from the Ross Ice Shelf. Synthetic aperture radar interferograms provide an independent test of model performance. The standard deviation of tide height variability is largest under the eastern ice shelf along the Shirase and Siple Coasts, where it can exceed 0.8 m. The maximum peak-to-peak tidal range in this region is ∼3 m. The best predictor for ocean tidal currents north of the ice front is a dynamics-based model that solves the depth-integrated shallow water equations with a linear representation of benthic friction rather than the more usual quadratic form. Tidal currents over the open Ross Sea are dominated by diurnal, topographically trapped vorticity waves. The strongest modelled currents exceed 1 m s−1 at spring tide in a narrow band along the upper continental slope in the north-western Ross Sea. Typical tidal currents in the central continental shelf area of the Ross Sea are 10–20 cm s−1. Under the ice shelf the typical currents are ∼5 cm s−1.

scholarly journals Field Studies of Bottom Crevasses in the Ross Ice Shelf, Antarctica

1983 ◽  
Vol 29 (101) ◽  
pp. 118-126 ◽  
Author(s):  
Kenneth C. Jezek ◽  
Charles R. Bentley
Keyword(s):  
Bottom Topography ◽  
Field Studies ◽  
Airborne Radar ◽  
Ice Thickness ◽  
Ice Shelf ◽  
The West ◽  
West Antarctic Ice Sheet ◽  
Ross Ice Shelf ◽  
West Antarctic ◽  
Grounding Line

AbstractSurface and airborne radar sounding data were used to identify and map fields of bottom crevasses on the Ross Ice Shelf. Two major concentrations of crevasses were found, one along the grid-eastern grounding line and another, made up of eight smaller sites, grid west of Crary Ice Rise. Based upon an analysis of bottom crevasse heights and locations, and of the strength of radar waves diffracted from the apex and bottom corners of the crevasses, we conclude that the crevasses are formed at discrete locations on the ice shelf. By comparing the locations of crevasse formation with ice thickness and bottom topography, we conclude that most of the crevasse sites are associated with ice rises. Hence we have postulated that six ice rises, in addition to Crary Ice Rise and Roosevelt Island, exist in the grid-western sector of the ice shelf. These “pinning points” may be important for interpreting the dynamics of the West Antarctic ice sheet.

scholarly journals Field Studies of Bottom Crevasses in the Ross Ice Shelf, Antarctica

1983 ◽  
Vol 29 (101) ◽  
pp. 118-126 ◽  
Author(s):  
Kenneth C. Jezek ◽  
Charles R. Bentley
Keyword(s):  
Bottom Topography ◽  
Field Studies ◽  
Airborne Radar ◽  
Ice Thickness ◽  
Ice Shelf ◽  
The West ◽  
West Antarctic Ice Sheet ◽  
Ross Ice Shelf ◽  
West Antarctic ◽  
Grounding Line

AbstractSurface and airborne radar sounding data were used to identify and map fields of bottom crevasses on the Ross Ice Shelf. Two major concentrations of crevasses were found, one along the grid-eastern grounding line and another, made up of eight smaller sites, grid west of Crary Ice Rise. Based upon an analysis of bottom crevasse heights and locations, and of the strength of radar waves diffracted from the apex and bottom corners of the crevasses, we conclude that the crevasses are formed at discrete locations on the ice shelf. By comparing the locations of crevasse formation with ice thickness and bottom topography, we conclude that most of the crevasse sites are associated with ice rises. Hence we have postulated that six ice rises, in addition to Crary Ice Rise and Roosevelt Island, exist in the grid-western sector of the ice shelf. These “pinning points” may be important for interpreting the dynamics of the West Antarctic ice sheet.

Nitrate-rich inland waters of the Ross Ice Shelf region, Antarctica

1994 ◽  
Vol 6 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Warwick F. Vincent ◽  
Clive Howard-Williams
Keyword(s):  
Ross Sea ◽  
Full Range ◽  
Dry Valleys ◽  
Ice Shelf ◽  
Ross Ice Shelf ◽  
Freeze Concentration ◽  
Coastal Marine ◽  
Antarctic Snow ◽  
Shelf Region ◽  
Surface Water Samples

Nutrient and major ion concentrations were measured in surface water samples from lakes, ponds and streams at sites 30–320 km south of McMurdo Sound: the Darwin Glacier region (79.7–80.0°S), Pyramid Trough in the southern Dry Valleys (78.2°S), and the McMurdo Ice Shelf ablation zone (77.8–78.4°S). These aquatic environments ranged from dilute meltwaters (conductivity <0.05 mS cm−1) to concentrated brines (>50 mS cm−1). The lowest nitrate concentrations were recorded at the sites closest to the seasonally open waters of the Ross Sea. Much higher values (100–142000mg NO3–Nm−3) were recorded at sites further south. These observations support the hypothesis that NO3 precipitation over Antarctica is of stratospheric rather than coastal marine origin. The nitrogen-rich waters contained chloride and nitrate in the ratio 5.45g Cl:1g N (C.V.=8.4%) which is within the range for Antarctic snow, and indicative of nitrate enrichment by freeze concentration processes. Cyanobacterial mats were conspicuous elements of the biota across the full range of salinities, and were usually dominated by oscilatoriacean species. Nitrogen-fixing cyanobacteria and diatoms were also represented in these benthic microbial communities at the more northern sites, but were absent from all samples from the Darwin Glacier region.

Continued northward expansion of the Ross Ice Shelf, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 93-98 ◽  
Author(s):  
Harry J. R. Keys ◽  
Stanley S. Jacobs ◽  
Lawson W. Brigham
Keyword(s):  
Ross Sea ◽  
Shelf Area ◽  
Ice Shelf ◽  
Ice Shelves ◽  
Ross Ice Shelf ◽  
Front Advance ◽  
Northward Expansion ◽  
High Elevations ◽  
The Antarctic ◽  
Local Variability

The last major calving event along the Ross Ice Shelf (RIS, Antarctica) front occurred a decade ago, following a substantial increase in the rate of ice-front advance in the few years preceding the event. This “B-9” event, on the eastern part of the front between Edward VII Peninsula and Roosevelt Island, removed ≈ 5100 km2of ice, about 100 years of advance in that sector, but reduced the ice-shelf area by only 1%. Since 1987 the entire ice front has continued to advance, more than regaining the area lost during the B-9 event. The western front is now well north of any position recorded during the last 150 years, and it lias not experienced major calving forat least 90 years. Ice-front heights generally decrease from east to west, but local variability is high. Elevations are relatively low from 171° to 177° W, the location of “warm” Modified Circumpolar Deep Water circulation beneath the outer ice shelf. Modern heights considerably exceed historical heights between 179° Wand 178° E and are lower west of 174° E, probably due to recent dynamic changes such as rifting and the western advance. The general advance of the RIS front and the period of several decades to more than a century that elapses between major calving events is consistent with a relatively stable ice front. This contrasts with several smaller ice shelves along the Antarctic Peninsula and McMurdo Ice Shelf in the Ross Sea which have retreated substantially during the past few decades.

scholarly journals Field Studies of Bottom Crevasses in the Ross Ice Shelf, Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 341-341
Author(s):  
Kenneth C. Jezek ◽  
Charles R. Bentley
Keyword(s):  
Bottom Topography ◽  
Field Studies ◽  
Airborne Radar ◽  
Ice Thickness ◽  
Ice Shelf ◽  
The West ◽  
West Antarctic Ice Sheet ◽  
Ross Ice Shelf ◽  
West Antarctic ◽  
Grounding Line

Surface and airborne radar sounding data were used to identify and map fields of bottom crevasses on the Ross Ice Shelf. Two major concentrations of crevasses were found, one along the grid-eastern grounding line and another, made up of eight smaller sites, grid-west of Crary Ice Rise.Based upon an analysis of bottom crevasse heights and locations, and of the strength of radar waves diffracted from the apex and bottom corners of the gridcrevasses, we conclude that the crevasses are formed at discrete locations on the ice shelf. By comparing the locations of crevasse formation with ice thickness and bottom topography, we conclude that most of the crevasse sites are associated with grounding. Hence we have postulated that six grounded areas, in addition to Crary Ice Rise and Roosevelt Island, exist in the grid-western sector of the ice shelf. These pinning points may be important for interpreting the dynamics of the West Antarctic ice sheet.

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