Numerical Simulation of Winter Katabatic Winds from West Antarctica Crossing Siple Coast and the Ross Ice Shelf

1994 ◽  
Vol 122 (7) ◽  
pp. 1417-1435 ◽  
Author(s):  
David H. Bromwich ◽  
Yang Du ◽  
Thomas R. Parish
Keyword(s):  
Numerical Simulation ◽  
West Antarctica ◽  
Ice Shelf ◽  
Katabatic Winds ◽  
Ross Ice Shelf

scholarly journals Ice Streams and Grounding Zones of West Antarctica and the Ross Ice Shelf (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 199-200 ◽  
Author(s):  
S. Shabtaie ◽  
C.R. Bentley
Keyword(s):  
Radar Data ◽  
Airborne Radar ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
West Antarctic

In 1984-85, airborne radar soundings were carried out over West Antarctic ice streams A, B, and C, the neighboring parts of the Ross Ice Shelf, and Crary Ice Rise. Here we use the radar data to map the boundaries of the ice streams, to calculate surface elevations, and to measure ice thicknesses. Lee thicknesses and surface elevations have been used together to map the grounding zones and ice rises (Figure 1).

scholarly journals Timing of stagnation of Ice Stream C, West Antarctica, from short-pulse radar studies of buried surface crevasses

1993 ◽  
Vol 39 (133) ◽  
pp. 553-561 ◽  
Author(s):  
Rory Retzlaff ◽  
Charles R. Bentley
Keyword(s):  
Short Pulse ◽  
Water Pressure ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
Pulse Radar ◽  
West Antarctic ◽  
Ice Stream ◽  
Inland Ice

AbstractFive short-pulse radar profiles were run across the edge of inactive Ice Stream C, one of the “Ross” ice streams that flows from the West Antarctic inland ice sheet into the Ross Ice Shelf. Scatter from buried crevasses, which we presume were at the surface of the ice stream when it was active, creates hyperbolae on the radar records. A density-depth curve and local accumulation rates were used to convert the picked travel times of the apices of the hyperbolae into stagnation ages for the ice stream. Stagnation ages are 130 ± 25 year for the three profiles farthest downstream and marginally less (100 ± 30 year) for the fourth. The profile farthest upstream shows a stagnation age of only ~30 year. We believe that these results indicate a “wave” of stagnation propagating at a diminishing speed upstream from the mouth of the ice stream, and we suggest that the stagnation process involves a drop in water pressure at the bed due to a conversion from sheet flow to channelized water flow.

scholarly journals Siple Coast Project research of Crary Ice Rise and the mouths of Ice Streams B and C, West Antarctica: review and new perspectives

1993 ◽  
Vol 39 (133) ◽  
pp. 538-552 ◽  
Author(s):  
Robert Bindschadler
Keyword(s):  
Surface Topography ◽  
Satellite Imagery ◽  
Image Data ◽  
Ice Thickness ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
The Past ◽  
Grounding Line

Abstract Satellite imagery is used as a basis to review and critique the results of studies at the mouths of Ice Streams Β and C and Crary Ice Rise. In many cases, these past analyses are extended by taking advantage of the broad coverage within each image. New perspectives are provided by the image data and some longstanding controversies are resolved. The grounding line is easily delineated and mapped in areas covered by imagery. Extensive areas of grounded ice with complex patterns of flow stripes are identified on the flanks of Crary Ice Rise. The imagery also allows a corrected map of surface topography in the vicinity of the Downstream Β camp. New questions are posed by hitherto unseen features. Data from the IGY traverse of the Ross Ice Shelf in 1957 are included to demonstrate that large changes have occurred in the past almost 30 years in the area upstream of Crary Ice Rise. These changes include modifications in the surface topography, elimination of crevasses and increases in the ice thickness by approximately 60 m.

scholarly journals The grounding zone of the Ross Ice Shelf, West Antarctica, from ice-penetrating radar

2011 ◽  
Vol 57 (205) ◽  
pp. 917-928 ◽  
Author(s):  
Joseph A. MacGregor ◽  
Sridhar Anandakrishnan ◽  
Ginny A. Catania ◽  
Dale P. Winebrenner
Keyword(s):  
Satellite Altimetry ◽  
In Situ Measurements ◽  
Airborne Radar ◽  
Ice Accretion ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
Persistent Layer

AbstractAs ice streams flow into the Ross Ice Shelf, West Antarctica, their bed coupling transitions from weak to transient to zero as the ice goes afloat. Here we explore the nature of the bed across these crucial grounding zones using ice-penetrating radar. We collected several ground-based 2 MHz radar transects across the grounding zones of Whillans and Kamb Ice Streams and inferred bed-reflectivity changes from in situ measurements of depth-averaged dielectric attenuation, made possible by the observation of both primary and multiple bed echoes. We find no significant change in the bed reflectivity across either grounding zone. Combined with reflectivity modeling, this observation suggests that a persistent layer of subglacial water (>∼0.2 m) is widespread several kilometers upstream of the grounding zone. Our results are consistent with previous inferences of gradual grounding zones across this sector of the Ross Ice Shelf from airborne radar and satellite altimetry. Separately, the only clear bed-reflectivity change that we observed occurs ∼40 km downstream of the Kamb Ice Stream grounding zone, which we attribute to the onset of marine ice accretion onto the base of the ice shelf. This onset is much nearer to the grounding zone than previously predicted.

scholarly journals Changes in the ice plain of Whillans Ice Stream, West Antarctica

2005 ◽  
Vol 51 (175) ◽  
pp. 620-636 ◽  
Author(s):  
Robert Bindschadler ◽  
Patricia Vornberger ◽  
Laurence Gray
Keyword(s):  
West Antarctica ◽  
Ice Shelf ◽  
Ross Ice Shelf ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Grounding Line ◽  
Local Areas ◽  
The Mean ◽  
Geometric Changes ◽  
Thinning Rate

AbstractData from the mouth of the decelerating Whillans Ice Stream (WIS), West Antarctica, spanning 42 years are reviewed. Deceleration has continued, with local areas of both thinning and thickening occurring. The mean thinning rate is 0.48 ± 0.77 ma–1. No consistent overall pattern is observed. Ice thickens immediately upstream of Crary Ice Rise where deceleration and divergence are strongest, suggesting expanded upstream influence of the ice rise. Thinning is prevalent on the Ross Ice Shelf. Grounding-line advance at a rate of 0.3 km a–1 is detected in a few locations. Basal stresses vary across an ice-stream transect with a zone of enhanced flow at the margin. Marginal shear is felt at the ice-stream center. Mass-balance values are less negative, but larger errors of earlier measurements mask any possible temporal pattern. Comparisons of the recent flow field with flow stripes suggest WIS contributes less ice to the deep subglacial channel carved by Mercer Ice Stream and now flows straighter. The general lack of geometric changes suggests that the regional velocity decrease is due to changing basal conditions.

scholarly journals Ice Streams and Grounding Zones of West Antarctica and the Ross Ice Shelf (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 199-200 ◽  
Author(s):  
S. Shabtaie ◽  
C.R. Bentley
Keyword(s):  
Radar Data ◽  
Airborne Radar ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
West Antarctic

In 1984-85, airborne radar soundings were carried out over West Antarctic ice streams A, B, and C, the neighboring parts of the Ross Ice Shelf, and Crary Ice Rise. Here we use the radar data to map the boundaries of the ice streams, to calculate surface elevations, and to measure ice thicknesses. Lee thicknesses and surface elevations have been used together to map the grounding zones and ice rises (Figure 1).

scholarly journals Characteristics of Ice Flow in Marie Byrd Land, Antarctica

1979 ◽  
Vol 24 (90) ◽  
pp. 63-75 ◽  
Author(s):  
K. E. Rose
Keyword(s):  
Flow Line ◽  
Landsat Imagery ◽  
Ice Sheet ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ice Flow ◽  
Ross Ice Shelf ◽  
Radio Echo Sounding ◽  
Echo Sounding

AbstractExtensive radio echo-sounding has mapped the part of West Antarctica between Byrd Station, the Whitmore Mountains, the Transantarctic Mountains, and the Ross Ice Shelf. The ice sheet in this area is dominated by five major sub-parallel ice streams (A–E), which are up to 100 km wide and extend inland from the grounding line of the Ross Ice Shelf for about 400 km. Their positions have been determined by crevassing seen on radio echo-sounding records, trimetrogon photographs, and Landsat imagery. The ice streams are characterized by their flat transverse cross-sections, while the intervening ice sheet exhibits domes and ridges. Ice flow lines are defined from the ice-surface contour pattern and the trend of the ice streams. It is apparent from this work that the flow line passing through Byrd Station joins ice stream D.The bedrock of the area is relatively smooth near the Ross Ice Shelf, becoming rougher near Byrd Station and especially so near the Whitmore Mountains. Bedrock troughs, which control the positions of the ice streams, are believed to have a tectonic origin.In this paper the role of the ice streams in the glaciological regime of West Antarctica is investigated from radio-echo data and estimates of balance velocity, basal shear stress, and basal temperatures.

scholarly journals Siple Coast Project research of Crary Ice Rise and the mouths of Ice Streams B and C, West Antarctica: review and new perspectives

1993 ◽  
Vol 39 (133) ◽  
pp. 538-552 ◽  
Author(s):  
Robert Bindschadler
Keyword(s):  
Surface Topography ◽  
Satellite Imagery ◽  
Image Data ◽  
Ice Thickness ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ross Ice Shelf ◽  
The Past ◽  
Grounding Line

AbstractSatellite imagery is used as a basis to review and critique the results of studies at the mouths of Ice Streams Β and C and Crary Ice Rise. In many cases, these past analyses are extended by taking advantage of the broad coverage within each image. New perspectives are provided by the image data and some longstanding controversies are resolved. The grounding line is easily delineated and mapped in areas covered by imagery. Extensive areas of grounded ice with complex patterns of flow stripes are identified on the flanks of Crary Ice Rise. The imagery also allows a corrected map of surface topography in the vicinity of the Downstream Β camp. New questions are posed by hitherto unseen features. Data from the IGY traverse of the Ross Ice Shelf in 1957 are included to demonstrate that large changes have occurred in the past almost 30 years in the area upstream of Crary Ice Rise. These changes include modifications in the surface topography, elimination of crevasses and increases in the ice thickness by approximately 60 m.

scholarly journals Characteristics of Ice Flow in Marie Byrd Land, Antarctica

1979 ◽  
Vol 24 (90) ◽  
pp. 63-75 ◽  
Author(s):  
K. E. Rose
Keyword(s):  
Flow Line ◽  
Landsat Imagery ◽  
Ice Sheet ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Streams ◽  
Ice Flow ◽  
Ross Ice Shelf ◽  
Radio Echo Sounding ◽  
Echo Sounding

AbstractExtensive radio echo-sounding has mapped the part of West Antarctica between Byrd Station, the Whitmore Mountains, the Transantarctic Mountains, and the Ross Ice Shelf. The ice sheet in this area is dominated by five major sub-parallel ice streams (A–E), which are up to 100 km wide and extend inland from the grounding line of the Ross Ice Shelf for about 400 km. Their positions have been determined by crevassing seen on radio echo-sounding records, trimetrogon photographs, and Landsat imagery. The ice streams are characterized by their flat transverse cross-sections, while the intervening ice sheet exhibits domes and ridges. Ice flow lines are defined from the ice-surface contour pattern and the trend of the ice streams. It is apparent from this work that the flow line passing through Byrd Station joins ice stream D.The bedrock of the area is relatively smooth near the Ross Ice Shelf, becoming rougher near Byrd Station and especially so near the Whitmore Mountains. Bedrock troughs, which control the positions of the ice streams, are believed to have a tectonic origin.In this paper the role of the ice streams in the glaciological regime of West Antarctica is investigated from radio-echo data and estimates of balance velocity, basal shear stress, and basal temperatures.

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