Monitoring Changes in Antarctic Ice Surface Topography: The Example of the Lambert Glacier/Amery Ice Shelf System

2004 ◽  
pp. 259-287
Author(s):  
Ute Christina Herzfeld
Keyword(s):  
Surface Topography ◽  
Ice Shelf ◽  
Ice Surface ◽  
Amery Ice Shelf ◽  
Lambert Glacier

scholarly journals Radio-echo sounding of the lambert glacier basin

1975 ◽  
Vol 15 (73) ◽  
pp. 103-111 ◽  
Author(s):  
V. I. Morgan ◽  
W. F. Budd
Keyword(s):  
Surface Topography ◽  
Sea Level ◽  
Drainage Basin ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Deep Trench ◽  
Glacier System ◽  
Amery Ice Shelf ◽  
Lambert Glacier ◽  
Echo Sounding

AbstractSeveral seasons of aerial ice-thickness soundings over the region of the Prince Charles Mountains, the Lambert Glacier system, the Amery Ice Shelf, and their drainage basin in east Antarctica have now been completed. The measurements provide detailed maps of surface topography and ice thickness over an area of about 2 X 105 km2. The equipment used consisted of a 100 MHz echo sounder designed and constructed by Antarctic Division and carried in a Pilatus Porter aircraft. ERTS imagery provides a valuable background for portraying the echo-sounding results. These results show that an extensive, deep subglacial valley system forms the basis of the large drainage basin with concave ice surface topography which channels the ice flow into the Amery Ice Shelf. Deep glacial streams penetrate a long way into the ice-sheet basin. The rock relief is considerable, varying from 3 000 m above (present) sea-level to 2 000 m below sea-level. A very deep subglacial trench exists in the region of the confluence of the Fisher, Mellor, and Lambert Glaciers where the ice thickness reaches 2 500 m. The low surface slope and high ice velocity are suggestive of high melt production in this region. The strong echo, together with the high bedrock back-slope, suggests that the deep trench may contain a basal melt lake.

scholarly journals Radio-echo sounding of the lambert glacier basin

1975 ◽  
Vol 15 (73) ◽  
pp. 103-111 ◽  
Author(s):  
V. I. Morgan ◽  
W. F. Budd
Keyword(s):  
Surface Topography ◽  
Sea Level ◽  
Drainage Basin ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Deep Trench ◽  
Glacier System ◽  
Amery Ice Shelf ◽  
Lambert Glacier ◽  
Echo Sounding

AbstractSeveral seasons of aerial ice-thickness soundings over the region of the Prince Charles Mountains, the Lambert Glacier system, the Amery Ice Shelf, and their drainage basin in east Antarctica have now been completed. The measurements provide detailed maps of surface topography and ice thickness over an area of about 2 X 105km2. The equipment used consisted of a 100 MHz echo sounder designed and constructed by Antarctic Division and carried in a Pilatus Porter aircraft. ERTS imagery provides a valuable background for portraying the echo-sounding results. These results show that an extensive, deep subglacial valley system forms the basis of the large drainage basin with concave ice surface topography which channels the ice flow into the Amery Ice Shelf. Deep glacial streams penetrate a long way into the ice-sheet basin. The rock relief is considerable, varying from 3 000 m above (present) sea-level to 2 000 m below sea-level. A very deep subglacial trench exists in the region of the confluence of the Fisher, Mellor, and Lambert Glaciers where the ice thickness reaches 2 500 m. The low surface slope and high ice velocity are suggestive of high melt production in this region. The strong echo, together with the high bedrock back-slope, suggests that the deep trench may contain a basal melt lake.

scholarly journals Mass budget of the grounded ice in the Lambert Glacier–Amery Ice Shelf system

2008 ◽  
Vol 48 ◽  
pp. 193-197 ◽  
Author(s):  
Wen Jiahong ◽  
Wang Yafeng ◽  
Liu Jiying ◽  
Kenneth C. Jezek ◽  
Philippe Huybrechts ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Surface Velocity ◽  
Ice Shelf ◽  
Outlet Glacier ◽  
Mass Budget ◽  
Ice Surface ◽  
Amery Ice Shelf ◽  
Lambert Glacier ◽  
Lambert Glacier Basin

AbstractWe used remote-sensing and in situ measurements of surface accumulation rate, ice surface velocity, thickness and elevation to evaluate the mass budgets of grounded ice-flow regimes that form the Lambert Glacier–Amery Ice Shelf system. Three distinct drainage regimes are considered: the western and eastern margins of the ice shelf, and the southern grounding line at the major outlet glacier confluence, which can be identified with drainage zones 9, 11 and 10 respectively of Giovinetto and Zwally (2000). Our findings show the entire grounded portion of the basin is approximately in balance, with a mass budget of –4.2±9.8 Gt a–1. Drainages 9, 10 and 11 are within balance to the level of our measurement uncertainty, with mass budgets of –2.5±2.8 Gt a–1, –2.6±7.8 Gt a–1 and 0.9±2.3 Gt a–1, respectively. The region upstream of the Australian Lambert Glacier basin (LGB) traverse has a net mass budget of 4.4±6.3 Gt a–1, while the downstream region has –8.9±9.9 Gt a–1. These results indicate that glacier drainages 9, 10 and 11, upstream and downstream of the Australian LGB traverse, are in balance to within our measurement error.

scholarly journals Modelling the response of the Lambert Glacier–Amery Ice Shelf system, East Antarctica, to uncertain climate forcing over the 21st and 22nd centuries

2014 ◽  
Vol 8 (3) ◽  
pp. 1057-1068 ◽  
Author(s):  
Y. Gong ◽  
S. L. Cornford ◽  
A. J. Payne
Keyword(s):  
Climate Model ◽  
Global Environmental Change ◽  
Ice Sheet ◽  
Adaptive Mesh ◽  
Ocean Model ◽  
East Antarctica ◽  
Ice Shelf ◽  
Amery Ice Shelf ◽  
Grounding Line ◽  
Lambert Glacier

Abstract. The interaction between the climate system and the large polar ice sheet regions is a key process in global environmental change. We carried out dynamic ice simulations of one of the largest drainage systems in East Antarctica: the Lambert Glacier–Amery Ice Shelf system, with an adaptive mesh ice sheet model. The ice sheet model is driven by surface accumulation and basal melt rates computed by the FESOM (Finite-Element Sea-Ice Ocean Model) ocean model and the RACMO2 (Regional Atmospheric Climate Model) and LMDZ4 (Laboratoire de Météorologie Dynamique Zoom) atmosphere models. The change of ice thickness and velocity in the ice shelf is mainly influenced by the basal melt distribution, but, although the ice shelf thins in most of the simulations, there is little grounding line retreat. We find that the Lambert Glacier grounding line can retreat as much as 40 km if there is sufficient thinning of the ice shelf south of Clemence Massif, but the ocean model does not provide sufficiently high melt rates in that region. Overall, the increased accumulation computed by the atmosphere models outweighs ice stream acceleration so that the net contribution to sea level rise is negative.

scholarly journals Surging of Fisher Glacier, Eastern Antarctica: Evidence From Geomorphology

1982 ◽  
Vol 28 (98) ◽  
pp. 23-28 ◽  
Author(s):  
Peter Wellman
Keyword(s):  
Climatic Change ◽  
The Other ◽  
Present Level ◽  
Altitude Range ◽  
Ice Shelf ◽  
Amery Ice Shelf ◽  
Lambert Glacier

AbstractA study of the geomorphology of the Prince Charles Mountains using colour vertical air photographs shows well–preserved old moraines throughout much of the outcrop area. Along Fisher Glacier, lower Lambert Glacier and the Amery Ice Shelf, within the altitude range 50–2 000 m, the old moraines show that the ice level had risen 150–200 m above the present level at least three times. Old moraines elsewhere show that none of the other glaciers had risen significantly in their upper parts; the rise of their lower parts was caused by the rise of lower Lambert Glacier and the Amery Ice Shelf. The changes in ice level are unlikely to be due to climatic change because this would not repeatedly affect only one glacier draining central Antarctica. It is thought that the changes in ice level are caused by repeated surges of Fisher Glacier.

scholarly journals Mass balance of the Lambert Glacier–Amery Ice Shelf system, East Antarctica: a comparison of computed balance fluxes and measured fluxes

2000 ◽  
Vol 46 (155) ◽  
pp. 561-570 ◽  
Author(s):  
Helen A. Fricker ◽  
Roland C. Warner ◽  
Ian Allison
Keyword(s):  
Mass Balance ◽  
Drainage System ◽  
Radar Altimeter ◽  
Drainage Basins ◽  
Ice Shelf ◽  
Amery Ice Shelf ◽  
Ice Sheet Mass Balance ◽  
Lambert Glacier ◽  
Lambert Glacier Basin

AbstractWe combine European Remote-sensing Satellite (ERS-1) radar altimeter surface elevations (Fricker and others, 2000) with six different accumulation distributions to compute balance fluxes for the Lambert Glacier–Amery Ice Shelf drainage system. These interpolated balance fluxes are compared with fluxes derived from in situ measurements of ice thickness and velocity at 73 stations of the Lambert Glacier basin traverse and at 11 stations further downstream, to assess the system’s state of balance. For the upstream line we obtain a range of imbalance estimates, from −23.8% to +19.9% of the observed flux, reflecting the sensitivity to the accumulation distributions. For some of the accumulation distributions the imbalance estimates vary significantly between different parts of the line. Imbalance estimates for the downstream line range from −17.7% to +70.2%, with four of the estimates exceeding +30%, again reflecting the sensitivity of the result to input accumulation, and strongly suggesting that the mass balance of the region between the two lines is positive. Our results confirm the importance of accurate estimates of accumulation in ice-sheet mass-balance studies. Furthermore, they suggest that it is not possible to accurately determine the state of balance of large Antarctic drainage basins on the basis of currently available accumulation distributions.

The Amery Ice Shelf and its hinterland

Polar Record ◽  
1960 ◽  
Vol 10 (64) ◽  
pp. 30-34 ◽  
Author(s):  
Malcolm Mellor ◽  
Graeme McKinnon
Keyword(s):  
Prydz Bay ◽  
Ice Shelf ◽  
Amery Ice Shelf ◽  
Antarctic Research ◽  
Lambert Glacier ◽  
The Antarctic

During the thirty years since the Amery Ice Shelf was first sighted there has been a steady accumulation of information, first on the ice shelf itself and later on the interesting mountains and glacier systems which lie to its south. The ice shelf occupies the head of a large embayment consisting of Prydz Bay and Mackenzie Bay, which deeply indents the coastline of the Antarctic mainland near the borders of MacRobertson Land and Princess Elizabeth Land. An associated valley runs south from the bay, between the Prince Charles Mountains and the Mawson Escarpment, and it is occupied by one of the world's largest valley glaciers, the Lambert Glacier. (In fact, recent findings by Soviet parties suggest that the Lambert Glacier is considerably longer than the Beardmore Glacier.) The exploration, survey and subsequent mapping of the ice shelf, and the mountains and glaciers of its hinterland, by Australian National Antarctic Research Expeditions in recent years has been a major contribution to Antarctic geography.

scholarly journals Geostatistical evaluation of satellite radar altimetry for high-resolution mapping of Lambert Glacier, Antarctica

1993 ◽  
Vol 17 ◽  
pp. 77-85 ◽  
Author(s):  
Ute C. Herzfeld ◽  
Craig S. Lingle ◽  
Li-Her Lee
Keyword(s):  
Noise Levels ◽  
Ice Shelf ◽  
High Resolution Mapping ◽  
Amery Ice Shelf ◽  
Resolution Mapping ◽  
Satellite Radar ◽  
Along Track ◽  
Lambert Glacier ◽  
Inland Ice ◽  
Satellite Radar Altimetry

The potential of satellite radar altimetry for high-resolution mapping of Antarctic ice streams is evaluated, using retracked and slope-corrected data from the Lambert Glacier and Amery Ice Shelf area, East Antarctica, acquired by Geosat during the Exact Repeat Mission (ERM), 1986–89. The map area includes lower Lambert Glacier north of 72.18°S, the southern Amery Ice Shelf, and the grounded inland ice sheet on both sides. The Geosat ERM altimetry is found to provide substantially more complete coverage than the 1978 Seasat altimetry, due to improved tracking. Variogram methods are used to estimate the noise levels in the data as a function of position throughout the map area. The spatial structure in the data is quantified by constructing experimental variograms using altimetry from the area of the grounding zone of Lambert Glacier, which is the area chiefly of interest in this topographically complex region. Kriging is employed to invert the along-track height measurements onto a fine-scale 3 km grid. The unsmoothed along-track Geosat ERM altimetry yields spatially continuous maps showing the main topographic features of lower Lambert Glacier, upper Amery Ice Shelf and the adjacent inland ice sheet. The probable position of the grounding line of Lambert Glacier is identified from a break in slope at the grounded ice/floating ice transition. The approximate standard error of the kriged map is inferred from the data noise levels.

Velocities of the Amery Ice Shelf's primary tributary glaciers, 2004–12

2015 ◽  
Vol 27 (5) ◽  
pp. 511-523 ◽  
Author(s):  
M.L. Pittard ◽  
J.L. Roberts ◽  
C.S. Watson ◽  
B.K. Galton-Fenzi ◽  
R.C. Warner ◽  
...  
Keyword(s):  
Surface Velocity ◽  
Ice Shelf ◽  
Ice Flow ◽  
Ice Shelves ◽  
Ice Surface ◽  
Amery Ice Shelf ◽  
Landsat 7 ◽  
One Year ◽  
Shelf Region

AbstractMonitoring the rate of ice flow into ice shelves is vital to understanding how, where and when mass changes occur in Antarctica. Previous observations of ice surface velocity indicate that the Amery Ice Shelf and tributary glaciers have been relatively stable over the period 1968 to 1999. This study measured the displacement of features on the ice surface over a sequence of Landsat 7 images separated by approximately one year and spanning 2004 to 2012 using the surface feature tracking software IMCORR. The focus is on the region surrounding the southern grounding zone of the Amery Ice Shelf and its primary tributary glaciers: the Fisher, Lambert and Mellor glaciers. No significant changes in surface velocity were observed over this period. Accordingly, the velocity fields from each image pair between 2004 and 2012 were used to synthesize an average velocity dataset of the Amery Ice Shelf region and to compare it to previously published velocity datasets and in situ global positioning system velocity observations. No significant change in ice surface velocities was found between 2004 and 2012 in the Amery Ice Shelf region, which suggests that it continues to remain stable.

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