Glaciological investigations of surging ice caps in Nordaustlandet, Svalbard, 1983

Polar Record ◽  
1985 ◽  
Vol 22 (139) ◽  
pp. 359-378 ◽  
Author(s):  
D. J. Drewry ◽  
O. Liestøl
Keyword(s):  
Digital System ◽  
Svalbard Archipelago ◽  
Ice Caps ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Polar Research Institute ◽  
Echo Sounding ◽  
Research Institute

AbstractDuring spring 1983 a joint British-Norwegian expedition from the Scott Polar Research Institute (SPRI) and the Norsk Polarinstitutt (NP) undertook a programme of glaciological research in the Svalbard archipelago. Work focussed on obtaining airborne radio echo sounding measurements using a newly-constructed digital system and some reconnaissance observations (temperatures, net mass budgets and ice velocities) on the ice caps of Nordaustlandet for the investigation of their surging behaviour. Valley glaciers in Spitsbergen and the ice cap on Kvitøya were also sounded from the air.

Surface and Bedrock Topography of Ice Caps in Iceland, Mapped by Radio Echo-Sounding

1986 ◽  
Vol 8 ◽  
pp. 11-18 ◽  
Author(s):  
Helgi Björnsson
Keyword(s):  
Surface Elevation ◽  
Ice Thickness ◽  
Volcanic Complex ◽  
Glacier Surface ◽  
Ice Caps ◽  
Ice Cap ◽  
North East ◽  
Ice Surface ◽  
Radio Echo Sounding ◽  
Echo Sounding

Since 1977, large areas on western Vatnajökull have been surveyed by ground-based, radio echo-sounding and the whole ice cap, HofsjökuIl, was surveyed in 1983. Detailed maps of the glacier-surface elevation and the sub-ice bedrock have been compiled. The instrumentation includes a 2–5 MHz, mono-pulse echo-sounder, for continuous profiling, a satellite geoceiver and Loran-C equipment, for navigation, and a precision pressure altimeter. The maps of western Vatnajökull cover about 1500 km2 and are compiled from 1500 km-long sounding lines, which yielded about 50 000 data points for ice thickness and 20 000 points for ice-surface elevation. The maps of HofsjökuIl cover 923 km2, the sounding lines were 1350 km long; 42 000 points were used for determining ice thickness and 30 000 for surface elevation. The maps obtained from these data are the first ones of the ice caps with surface elevation of known accuracy. The bedrock map of western Vatnajökull shows details of volcanic ridges and subglacial valleys, running north-east to south-west, as well as the central, volcanic complexes, Hamarinn, Bárdarbunga, and Grimsvtön and the related fissure swarms. The map of Hofsjökull reveals a large volcanic complex, with a 650 m deep caldera. The landforms in southern Hofsjökull are predominantly aligned from north to south, but those in the northern ice cap run north by 25° east.

scholarly journals Surface and Bedrock Topography of Ice Caps in Iceland, Mapped by Radio Echo-Sounding

1986 ◽  
Vol 8 ◽  
pp. 11-18 ◽  
Author(s):  
Helgi Björnsson
Keyword(s):  
Surface Elevation ◽  
Ice Thickness ◽  
Volcanic Complex ◽  
Glacier Surface ◽  
Ice Caps ◽  
Ice Cap ◽  
North East ◽  
Ice Surface ◽  
Radio Echo Sounding ◽  
Echo Sounding

Since 1977, large areas on western Vatnajökull have been surveyed by ground-based, radio echo-sounding and the whole ice cap, HofsjökuIl, was surveyed in 1983. Detailed maps of the glacier-surface elevation and the sub-ice bedrock have been compiled. The instrumentation includes a 2–5 MHz, mono-pulse echo-sounder, for continuous profiling, a satellite geoceiver and Loran-C equipment, for navigation, and a precision pressure altimeter. The maps of western Vatnajökull cover about 1500 km2 and are compiled from 1500 km-long sounding lines, which yielded about 50 000 data points for ice thickness and 20 000 points for ice-surface elevation. The maps of HofsjökuIl cover 923 km2, the sounding lines were 1350 km long; 42 000 points were used for determining ice thickness and 30 000 for surface elevation. The maps obtained from these data are the first ones of the ice caps with surface elevation of known accuracy. The bedrock map of western Vatnajökull shows details of volcanic ridges and subglacial valleys, running north-east to south-west, as well as the central, volcanic complexes, Hamarinn, Bárdarbunga, and Grimsvtön and the related fissure swarms. The map of Hofsjökull reveals a large volcanic complex, with a 650 m deep caldera. The landforms in southern Hofsjökull are predominantly aligned from north to south, but those in the northern ice cap run north by 25° east.

Airborne radio echo sounding of glaciers in Svalbard

Polar Record ◽  
1980 ◽  
Vol 20 (126) ◽  
pp. 261-266 ◽  
Author(s):  
D. J. Drewry ◽  
O. Liestøl ◽  
C. S. Neal ◽  
O. Orheim ◽  
B. Wold
Keyword(s):  
Ice Thickness ◽  
Wide Range ◽  
Radio Echo Sounding ◽  
Polar Research Institute ◽  
Echo Sounding ◽  
Research Institute

During April–May 1980 the Scott Polar Research Institute (SPRI) and Norsk Polarinstitutt (NPI) conducted a joint programme of radio echo sounding (RES) in Svalbard. The principal aims were to evaluate the performance of SPRI 60 MHz echo sounding equipment of Svalbard glaciers, to measure ice thickness over a wide range of conditions, and to investigate specific glaciers which are the focus of current glaciological studies.

scholarly journals The newly developed airborne radio-echo sounding system of the AWI as a glaciological tool

1999 ◽  
Vol 29 ◽  
pp. 231-238 ◽  
Author(s):  
U. Nixdorf ◽  
D. Steinhage ◽  
U. Meyer ◽  
L. Hempel ◽  
M. Jenett ◽  
...  
Keyword(s):  
Digital Data ◽  
Radar Signal ◽  
Ice Shelves ◽  
System Sensitivity ◽  
Ice Caps ◽  
Radio Echo Sounding ◽  
Recorded Data ◽  
Along Track ◽  
Echo Sounding

AbstractSince 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system for remote-sensing studies of the polar ice caps in Antarctica and in Greenland. It is used to map ice thicknesses and internal layernigs of glaciers, ice sheets and ice shelves, and is capable of penetrating ice thicknesses of up to 4 km. The system was designed and built by AWI in cooperation with Aerodata Flugmeßtechnik GmbH, Technische Umversitat Hamburg-Harburg and the Deutsches Zentrum fur Luft- und Raumfahrt e.V. The system uses state-of-the-art techniques, and results in high vertical (5 m) as well as along-track (3.25 m) resolution. The radar signal is a 150 MHz burst with a duration of 60 or 600 ns. The peak power is 1.6 kW, and the system sensitivity is 190 dB. The short backfire principle has been adopted and optimized for antennae used on Polar2, a Dormer 228-100 aircraft, resulting in an antenna gain of 14 dB each. Digital data recording allows further processing. The quality of the recorded data can be monitored on screen and as online analogue plots during the flight.

scholarly journals Results from the Radio Echo-Sounding on Parts of the Jostedalsbreen Ice Cap, Norway

1986 ◽  
Vol 8 ◽  
pp. 156-158 ◽  
Author(s):  
Arne Chr. Saetrang ◽  
Bjørn Wold
Keyword(s):  
Ice Thickness ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Subglacial Topography ◽  
Echo Sounding

The paper describes instrumentation, navigation methods, and interpretation problems from radio echo-sounding on parts of Jostedalsbreen. A map of the subglacial topography is presented. Ice thickness ranges from 60 m to 600 m with most sections between 150 m and 300 m.

scholarly journals Positive mass balance during the late 20th century on Austfonna, Svalbard, revealed using satellite radar interferometry

2007 ◽  
Vol 46 ◽  
pp. 117-122 ◽  
Author(s):  
Suzanne Bevan ◽  
Adrian Luckman ◽  
Tavi Murray ◽  
Helena Sykes ◽  
Jack Kohler
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Radar Interferometry ◽  
The Arctic ◽  
Late 20Th Century ◽  
Ice Caps ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Increasing Temperature

AbstractDetermining whether increasing temperature or precipitation will dominate the cryospheric response to climate change is key to forecasting future sea-level rise. The volume of ice contained in the ice caps and glaciers of the Arctic archipelago of Svalbard is small compared with that of the Greenland or Antarctic ice sheets, but is likely to be affected much more rapidly in the short term by climate change. This study investigates the mass balance of Austfonna, Svalbard’s largest ice cap. Equilibrium-line fluxes for the whole ice cap, and for individual drainage basins, were estimated by combining surface velocities measured using satellite radar interferometry with ice thicknesses derived from radio-echo sounding. These fluxes were compared with balance fluxes to reveal that during the 1990s the total mass balance of the accumulation zone was (5.6±2.0)×108m3 a–1. Three basins in the quiescent phase of their surge cycles contributed 75% of this accumulation. The remaining volume may be attributable either to as yet unidentified surge-type glaciers, or to increased precipitation. This result emphasizes the importance of considering the surge dynamics of glaciers when attempting to draw any conclusions on climate change based on snapshot observations of the cryosphere.

scholarly journals Results from the Radio Echo-Sounding on Parts of the Jostedalsbreen Ice Cap, Norway

1986 ◽  
Vol 8 ◽  
pp. 156-158 ◽  
Author(s):  
Arne Chr. Saetrang ◽  
Bjørn Wold
Keyword(s):  
Ice Thickness ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Subglacial Topography ◽  
Echo Sounding

The paper describes instrumentation, navigation methods, and interpretation problems from radio echo-sounding on parts of Jostedalsbreen. A map of the subglacial topography is presented. Ice thickness ranges from 60 m to 600 m with most sections between 150 m and 300 m.

Antarctic airborne radio echo sounding, 1977–78

Polar Record ◽  
1978 ◽  
Vol 19 (120) ◽  
pp. 267-273 ◽  
Author(s):  
D. J. Drewry ◽  
D. T. Meldrum
Keyword(s):  
National Science Foundation ◽  
Austral Summer ◽  
Applied Physics ◽  
Joint Project ◽  
Johns Hopkins University ◽  
The Us ◽  
National Science ◽  
Radio Echo Sounding ◽  
Polar Research Institute ◽  
Echo Sounding

During the austral summer 1977–78 the Scott Polar Research Institute (SPRI) conducted a fifth season of airborne radio echo sounding in Antarctica as part of a joint project with the US National Science Foundation Division of Polar Programs (NSF-DPP) and the Technical University of Denmark (TUD). In addition, trials were undertaken of a magnetometer installation, developed and operated, under NSF contract, by the Applied Physics Laboratory (APL) of the Johns Hopkins University, USA.

scholarly journals Development of a subglacial lake monitored with radio-echo sounding: Case study from the Eastern Skaftá Cauldron in the Vatnajökull ice cap, Iceland

2021 ◽  
Author(s):  
Eyjólfur Magnússon ◽  
Finnur Pálsson ◽  
Magnús T. Gudmundsson ◽  
Thórdís Högnadóttir ◽  
Cristian Rossi ◽  
...  
Keyword(s):  
Lake Area ◽  
Ice Cap ◽  
Lake Volume ◽  
Digital Elevation ◽  
Geothermal Activity ◽  
Before And After ◽  
Radio Echo Sounding ◽  
Water Volumes ◽  
Elevation Model ◽  
Echo Sounding

Abstract. We present repeated radio-echo sounding (RES, 5 MHz) on a profile grid over the Eastern Skaftá Cauldron (ESC) in Vatnajökull ice cap, Iceland. The ESC is ~3 km wide and 50–150 m deep ice cauldron created and maintained by subglacial geothermal activity of ~1 GW. Beneath the cauldron and 200–400 m thick ice, water accumulates in a lake and is released semi-regularly in jökulhlaups. The RES record consists of annual surveys with 200–400 m between profiles in early summers of 2014–2020. Comparison of the RES surveys (2D migrated profiles) reveals variable lake area (0.5–4.1 km2) and enables traced reflections from the lake roof to be distinguished from bedrock reflections. This allows construction of a digital elevation model (DEM) of the bedrock in the area, further constrained by two borehole measurements at the cauldron centre. It also allows creation of lake thickness maps and an estimate of lake volume at the time of each survey, which we compare with lowering patterns and released water volumes obtained from surface DEMs obtained before and after jökulhlaups. The estimated lake volume is 250 × 106 m3 in June 2015 but 320 ± 20 × 106 m3 drained from the cauldron in October 2015. In June 2018, RES profiles reveal a lake volume of 185 × 106 m3 while 220 ± 30 × 106 m3 was released in a jökulhlaup in August 2018. Considering the water accumulation over the periods between RES surveys and jökulhlaups, this indicates 10–20 % uncertainty in the RES-derived volumes at times when significant jökulhlaups may be expected.

scholarly journals Radio Echo-Sounding of Spitsbergen Glaciers: Problems in the Interpretation of Layer and Bottom Returns

1984 ◽  
Vol 30 (104) ◽  
pp. 16-21 ◽  
Author(s):  
J. A. Dowdeswell ◽  
D.J. Drewry ◽  
O. Liestøl ◽  
O. Orheim
Keyword(s):  
Melting Point ◽  
Water Content ◽  
Ice Thickness ◽  
Drill Core ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Pressure Melting ◽  
Radio Frequencies ◽  
Similar Depth ◽  
Echo Sounding

AbstractAirborne radio echo-sounding of Spitsbergen glaciers during 1980 used 60 MHz SPR1 Mk IV equipment. On several glaciers results showed unambiguous bottom returns at depths 2–3 times those reported in previous Soviet echo-sounding at 440 and 620 MHz. Comparison of 60 MHZ records and independent gravity-surveyed ice thickness for two glaciers agreed to within 10%, whereas Soviet ice thicknesses were only 30–60% of gravity depths. Soviet bed echoes often coincided closely with an internal reflecting horizon recorded by the SPRI Mk IV system, and it is shown that Soviet U.H.F. equipment failed to penetrate to the true glacier bed on a number of ice masses (e.g. Finsterwalderbreen, Kongsvegen, Negribreen). This was probably due to increased absorption and scattering at higher radio frequencies, related to the inhomogeneous nature of Spitsbergen glaciers, which are often at or near the pressure-melting point. Both 60 MHz and U.H.F. equipment seldom recorded bed echoes in ice-cap accumulation areas (e.g. Isachsenfonna), where firn soaking during summer and 10 m temperatures of zero degrees have been observed. An isolated internal reflecting horizon was recorded on many glaciers. It is unlikely to be a moraine layer, but may be related to ice with a water content of 1–2% observed at a similar depth (115 m) in a drill core from Fridtjovbreen.

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