TY - GEN
T1 - Estimating ice thickness in south Georgia from SRTM elevation data 2012
AU - Cooper, Paul R.
AU - Tate, James W.
AU - Cook, Alison J.
N1 - © 2012 Springer-Verlag GmbH Berlin Heidelberg
The author was not affiliated to SAMS at the time of publication
PY - 2012/1/1
Y1 - 2012/1/1
N2 - South Georgia is a glaciated island in the South Atlantic, which provides a primary nesting site for the albatrosses and petrels of the Southern Ocean. 60% of the island is covered by glaciers and ice fields, and the majority of the coastal glaciers are observed to be retreating. A small number of these glaciers are advancing, and others are retreating at anomalously fast rates. As the status of these glaciers is important for environmental management of South Georgia, potentially controlling the spread of invasive species into currently pristine regions, it is necessary to understand the pattern of glacier change in South Georgia. However, detailed study of the glaciology of South Georgia is hampered by lack of measurements of the thickness of the ice. Because of the logistic difficulties of operating on South Georgia, there are no conventional ice thickness measurements from drilling, radar or seismic techniques, and it is unlikely that these will be available in the near future.This paper addresses this lack of basic information by using surface slope data to estimate the ice thickness of glaciers and ice fields in South Georgia. The surface slope data are derived using surface elevations from the Shuttle Radar Topographic Mission, which provides elevation measurements with a high relative accuracy. The estimate of ice thickness critically depends on assumptions about the conditions in the ice column and at the base of the ice mass, and areas where the estimate is clearly in error provide an insight into changed ice flow conditions or the environment at the ice/rock interface. These anomalous regions are then compared withglacier change data, providing insights into the reasons for the unusually rapidretreat or advance of certain glaciers. The paper describes the methodology used to compute ice thickness values, with an estimate of accuracy and variability of the thickness measures under different assumptions. The paper then identifies regions with anomalous thickness measurements, and seeks to ascertain why the thickness measurement is unreliable in certain regions. Finally these anomalous areas are compared with coastal change data to suggest why certain glaciers are retreating or advancing more rapidly than the norm for South Georgia, and to make predictions concerning future glacier change.
AB - South Georgia is a glaciated island in the South Atlantic, which provides a primary nesting site for the albatrosses and petrels of the Southern Ocean. 60% of the island is covered by glaciers and ice fields, and the majority of the coastal glaciers are observed to be retreating. A small number of these glaciers are advancing, and others are retreating at anomalously fast rates. As the status of these glaciers is important for environmental management of South Georgia, potentially controlling the spread of invasive species into currently pristine regions, it is necessary to understand the pattern of glacier change in South Georgia. However, detailed study of the glaciology of South Georgia is hampered by lack of measurements of the thickness of the ice. Because of the logistic difficulties of operating on South Georgia, there are no conventional ice thickness measurements from drilling, radar or seismic techniques, and it is unlikely that these will be available in the near future.This paper addresses this lack of basic information by using surface slope data to estimate the ice thickness of glaciers and ice fields in South Georgia. The surface slope data are derived using surface elevations from the Shuttle Radar Topographic Mission, which provides elevation measurements with a high relative accuracy. The estimate of ice thickness critically depends on assumptions about the conditions in the ice column and at the base of the ice mass, and areas where the estimate is clearly in error provide an insight into changed ice flow conditions or the environment at the ice/rock interface. These anomalous regions are then compared withglacier change data, providing insights into the reasons for the unusually rapidretreat or advance of certain glaciers. The paper describes the methodology used to compute ice thickness values, with an estimate of accuracy and variability of the thickness measures under different assumptions. The paper then identifies regions with anomalous thickness measurements, and seeks to ascertain why the thickness measurement is unreliable in certain regions. Finally these anomalous areas are compared with coastal change data to suggest why certain glaciers are retreating or advancing more rapidly than the norm for South Georgia, and to make predictions concerning future glacier change.
KW - Shuttle Radar Topography Mission
KW - Surface Slope
KW - Glacier Change
KW - Valley Wall
KW - Thickness Gradient
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U2 - 10.1007/978-3-642-25926-5_17
DO - 10.1007/978-3-642-25926-5_17
M3 - Conference contribution
AN - SCOPUS:84885203794
SN - 9783642259258
T3 - Lecture Notes in Geoinformation and Cartography
SP - 227
EP - 239
BT - Advances in Spatial Data Handling and GIS - 14th International Symposium on Spatial Data Handling, SDH 2010
T2 - 14th International Symposium on Spatial Data Handling, SDH 2010
Y2 - 26 May 2010 through 28 May 2010
ER -