Satellite Radar Interferometry for Monitoring Ice Sheet Motion: Application to an Antarctic Ice Stream

Goldstein, Robert S.; Engelhardt, Hermann; Kamb, Barclay; Frolich, R. M.

doi:10.1126/science.262.5139.1525

Cited by 660 publications

(378 citation statements)

References 32 publications

Supporting

Mentioning

359

Contrasting

Unclassified

Order By: Relevance

“…We applied both SAR interferometry (InSAR) (Goldstein et al, 1993;Joughin et al, 1996) as well as the SAR offsettracking method (Strozzi et al, 2002;Rignot et al, 2011;Paul et al, 2013) in order to estimate glacier velocities. The InSAR method measures displacement in the radar line-ofsight (LOS) direction, with a precision of the order of millimetres to centimetres, while offset tracking provides information about azimuth and range surface displacements, with a precision of the order of decimetres to metres.…”

Section: Velocity Measurementsmentioning

confidence: 99%

Surge dynamics in the Nathorstbreen glacier system, Svalbard

2014

View full text Add to dashboard Cite

Abstract. Nathorstbreen glacier system (NGS) recently experienced the largest surge in Svalbard since 1936, and this was examined using spatial and temporal observations from DEM differencing, time series of surface velocities from satellite synthetic aperture radar (SAR) and other sources. The upper basins with maximum accumulation during quiescence corresponded to regions of initial lowering. Initial speed-up exceeded quiescent velocities by a factor of several tens. This suggests that polythermal glacier surges are initiated in the temperate area before mass is displaced downglacier. Subsequent downglacier mass displacement coincided with areas where glacier velocity increased by a factor of 100-200 times (stage 2). After more than 5 years, the joint NGS terminus advanced abruptly into the fjord during winter, increasing velocities even more. The advance was followed by up-glacier propagation of crevasses, indicating the middle and subsequently the upper part of the glaciers reacting to the mass displacement. NGS advanced ∼15 km, while another ∼3 km length was lost due to calving. Surface lowering of ∼50 m was observed in some up-glacier areas, and in 5 years the total glacier area increased by 20 %. Maximum measured flow rates were at least 25 m d −1 , 2500 times quiescent velocity, while average velocities were about 10 m d −1 . The surges of Zawadzkibreen cycle with ca. 70-year periods.

show abstract

Section: Velocity Measurementsmentioning

confidence: 99%

Surge dynamics in the Nathorstbreen glacier system, Svalbard

2014

View full text Add to dashboard Cite

show abstract

“…[4] We use interferometric synthetic aperture radar (InSAR) data acquired by the European Remote Sensing (ERS-1 and ERS-2) satellite systems to measure changes in the position of the PIG hinge line over the period 1992-2011 [Gabriel et al, 1989;Goldstein et al, 1993;Rignot, 1998a]. The InSAR data set consists of synthetic aperture radar (SAR) images recorded in 1992,1996,1999,2000, and 2011 during dedicated periods when the satellites orbited in short repeat cycles.…”

Section: Methodsmentioning

confidence: 99%

Sustained retreat of the Pine Island Glacier

Park

Gourmelen

Shepherd

et al. 2013

Geophysical Research Letters

123

133

View full text Add to dashboard Cite

[1] We use satellite observations to show that, between 1992 and 2011, the Pine Island Glacier hinge line retreated at a rate of 0.95 AE 0.09 km yr À1 despite a progressive steepening and shoaling of the glacier surface and bedrock slopes, respectively, which ought to impede retreat. The retreat has remained constant because the glacier terminus has thinned at an accelerating rate of 0.53 AE 0.15 m yr À2 , with comparable changes upstream. This acceleration is consistent with an intensification of ocean-driven melting in the cavity beneath the floating section of the glacier. The pattern of hinge-line retreat meanders and is concentrated in isolated regions until ice becomes locally buoyant. Because the glacier-ocean system does not appear to have reached a position of relative stability, the lower limit of sea level projections may be too conservative.

show abstract

“…ERS-1/2 InSAR measures the displacement of the ice surface in the radarlooking direction (Goldstein et al 1993). Three look directions are required to measure ice velocity in vector form.…”

Section: Methodology and Datasets (A ) Satellite Techniquesmentioning

confidence: 99%

Changes in ice dynamics and mass balance of the Antarctic ice sheet

Rignot

2006

Phil. Trans. R. Soc. A.

100

View full text Add to dashboard Cite

The concept that the Antarctic ice sheet changes with eternal slowness has been challenged by recent observations from satellites. Pronounced regional warming in the Antarctic Peninsula triggered ice shelf collapse, which led to a 10-fold increase in glacier flow and rapid ice sheet retreat. This chain of events illustrated the vulnerability of ice shelves to climate warming and their buffering role on the mass balance of Antarctica. In West Antarctica, the Pine Island Bay sector is draining far more ice into the ocean than is stored upstream from snow accumulation. This sector could raise sea level by 1 m and trigger widespread retreat of ice in West Antarctica. Pine Island Glacier accelerated 38% since 1975, and most of the speed up took place over the last decade. Its neighbour Thwaites Glacier is widening up and may double its width when its weakened eastern ice shelf breaks up. Widespread acceleration in this sector may be caused by glacier ungrounding from ice shelf melting by an ocean that has recently warmed by 0.3 °C. In contrast, glaciers buffered from oceanic change by large ice shelves have only small contributions to sea level. In East Antarctica, many glaciers are close to a state of mass balance, but sectors grounded well below sea level, such as Cook Ice Shelf, Ninnis/Mertz, Frost and Totten glaciers, are thinning and losing mass. Hence, East Antarctica is not immune to changes.

show abstract

Satellite Radar Interferometry for Monitoring Ice Sheet Motion: Application to an Antarctic Ice Stream

Cited by 660 publications

References 32 publications

Surge dynamics in the Nathorstbreen glacier system, Svalbard

Surge dynamics in the Nathorstbreen glacier system, Svalbard

Sustained retreat of the Pine Island Glacier

Changes in ice dynamics and mass balance of the Antarctic ice sheet

Contact Info

Product

Resources

About