A comparative study of changes in the Lambert Glacier/Amery Ice Shelf system, East Antarctica, during 2004–2008 using gravity and surface elevation observations

ABSTRACTWe present results of a regional comparative study of surface mass changes from 2004 to 2008 based on Gravity Recovery and Climate Experiment (GRACE), The Ice, Cloud and Land Elevation Satellite (ICESat) and CHINARE observations over the Lambert Glacier/Amery Ice Shelf system (LAS). Estimation of the ICESat mass change rates benefitted from the density measurements along the CHINARE traverse and a spatial density adjustment method for reducing the effect of spatial density variations. In the high-elevation inland region, a positive trend was estimated from both ICESat and GRACE data, which is in line with the CHINARE accumulation measurements. In the coastal region, there were areas with high level accumulations in both ICESat and GRACE trend maps. In many high flow-speed glacier areas, negative mass change rates may be caused by dynamic ice flow discharges that have surpassed the snow accumulation. Overall, the mass change rate estimate in the LAS of 2004–2008 from the GRACE, ICESat and CHINARE data is 5.41 ± 4.59 Gt a−1, indicating a balanced to slightly positive mass trend. Along with other published results, this suggests that a longer-term positive mass trend in the LAS may have slowed in recent years.

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

The Cryosphere ◽

10.5194/tc-8-1057-2014 ◽

2014 ◽

Vol 8 (3) ◽

pp. 1057-1068 ◽

Cited By ~ 20

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.

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Radio-echo sounding of the lambert glacier basin

Journal of Glaciology ◽

10.3189/s0022143000034316 ◽

1975 ◽

Vol 15 (73) ◽

pp. 103-111 ◽

Cited By ~ 1

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.

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Surging of Fisher Glacier, Eastern Antarctica: Evidence From Geomorphology

Journal of Glaciology ◽

10.1017/s0022143000011758 ◽

1982 ◽

Vol 28 (98) ◽

pp. 23-28 ◽

Cited By ~ 14

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.

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Results From The Amery Ice Shelf Project

Annals of Glaciology ◽

10.1017/s0260305500002494 ◽

1982 ◽

Vol 3 ◽

pp. 36-41 ◽

Cited By ~ 75

Author(s):

W. F. Budd ◽

M. J. Corry ◽

T. H. Jacka

Keyword(s):

High Strain ◽

Ice Core ◽

Snow Accumulation ◽

Ice Thickness ◽

Surface Slope ◽

Ice Shelf ◽

Substantial Growth ◽

Basal Ice ◽

Amery Ice Shelf ◽

Comprehensive Study

The major results from a comprehensive study of the Amery Ice Shelf are presented, following the work of a wintering expedition in 1968 and supplemented by further measurements during the summer seasons of 1969 to 1971. The Programme included ice-core drilling, oversnow surveys for ice movement and optical levelling, ice-thickness sounding, and measurements of snow accumulation. The new data obtained provide the basis for a more accurate assessment of the mass balance and dynamics of the ice shelf than was possible from the earlier surveys. The results indicate a substantial growth of basal ice under the ice shelf inland where the ice thickness is greater than 450 m. Further towards the ice front the high strain thinning is approximately balanced by the horizontal ice advection. The velocity distribution over the ice shelf is primarily governed by a substantial surface slope towards the ice front and high restraining shear stress along the sides.

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

Journal of Glaciology ◽

10.3189/172756500781832765 ◽

2000 ◽

Vol 46 (155) ◽

pp. 561-570 ◽

Cited By ~ 53

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.

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The Amery Ice Shelf and its hinterland

Polar Record ◽

10.1017/s0032247400050579 ◽

1960 ◽

Vol 10 (64) ◽

pp. 30-34 ◽

Cited By ~ 28

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.

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

Annals of Glaciology ◽

10.1017/s0260305500012647 ◽

1993 ◽

Vol 17 ◽

pp. 77-85 ◽

Cited By ~ 26

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.

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Results From The Amery Ice Shelf Project

Annals of Glaciology ◽

10.3189/s0260305500002494 ◽

1982 ◽

Vol 3 ◽

pp. 36-41 ◽

Cited By ~ 12

Author(s):

W. F. Budd ◽

M. J. Corry ◽

T. H. Jacka

Keyword(s):

High Strain ◽

Ice Core ◽

Snow Accumulation ◽

Ice Thickness ◽

Surface Slope ◽

Ice Shelf ◽

Substantial Growth ◽

Basal Ice ◽

Amery Ice Shelf ◽

Comprehensive Study

The major results from a comprehensive study of the Amery Ice Shelf are presented, following the work of a wintering expedition in 1968 and supplemented by further measurements during the summer seasons of 1969 to 1971. The Programme included ice-core drilling, oversnow surveys for ice movement and optical levelling, ice-thickness sounding, and measurements of snow accumulation. The new data obtained provide the basis for a more accurate assessment of the mass balance and dynamics of the ice shelf than was possible from the earlier surveys.The results indicate a substantial growth of basal ice under the ice shelf inland where the ice thickness is greater than 450 m. Further towards the ice front the high strain thinning is approximately balanced by the horizontal ice advection.The velocity distribution over the ice shelf is primarily governed by a substantial surface slope towards the ice front and high restraining shear stress along the sides.

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