scholarly journals Ground-penetrating radar measurements of 64 Austrian glaciers between 1995 and 2010

2013 ◽  
Vol 54 (64) ◽  
pp. 179-188 ◽  
Author(s):  
Andrea Fischer ◽  
Michael Kuhn

Abstract The ongoing retreat of mountain glaciers necessitates the development of future scenarios of glacier runoff. These scenarios are not only governed by future climate scenarios influencing glacier mass balance but also by the glacier volumes, which are subject to melt. Ground-penetrating radar (GPR) is a valuable tool for measuring the thickness of mountain glaciers, although ground-based measurements are labour-intensive, so not all glaciers can be surveyed. This study presents the results of GPR surveys on 64 Alpine glaciers, carried out between 1995 and 2010. The glacier areas range from 0.001 to 18.4 km2, and their ice thickness was surveyed with an average density of 36 points km-2. The point measurements were extrapolated manually to derive volume maps. The mean ice thickness varies between 10 and 92 m; the maximum ice thickness is about three times the mean thickness. According to the glacier state recorded in the second glacier inventory, the 64 glaciers cover an area of 223.3 ± 3.6 km2, with a mean thickness of 50 ± 3 m and a glacier volume of 11.9 ± 1.1 km3. The mean maximum ice thickness is 119 ± 5m.

Author(s):  
C. Bello ◽  
N. Santillan ◽  
A. Cochachin ◽  
S. Arias ◽  
W. Suarez

Abstract. Ground Penetrating Radar (GPR) survey was carried out to estimate the ice thickness and mapping the bedrock topography at Znosko glacier on King George Island, Antarctic Peninsula during 25th Peruvian Antarctic Expedition (2018). GPR surveying did at 5.2 MHz frequency with a 16 m antenna gap (transmitter and receiver). The mean ice thickness profiles vary from 7 to 123 m across the 350 m profile length. This high-resolution survey also identified a different type of ices and glaciological features which will help in modelling the nature of the glaciers in the future.


2012 ◽  
Vol 58 (211) ◽  
pp. 904-914 ◽  
Author(s):  
Zbynĕk Engel ◽  
Daniel Nývlt ◽  
Kamil Láska

AbstractThis study calculates area, volume and elevation changes of two glaciers on James Ross Island, Antarctica, during the period 1979-2006. Davies Dome is a small ice cap. Whisky Glacier is a valley glacier. Ground-penetrating radar surveys indicate ice thickness, which was used for calculations of the bed topography and volume of both glaciers. Maximum measured ice thicknesses of Davies Dome and Whisky Glacier are 83 ± 2 and 157 ± 2 m, respectively. Between 1979 and 2006, the area of the ice cap decreased from 6.23 ± 0.05 km2 to 4.94 ± 0.01 km2 (-20.7%), while the area of the valley glacier reduced from 2.69 ± 0.02 km2 to 2.40 ± 0.01 km2 (-10.6%). Over the same period the volume of the ice cap and valley glacier reduced from 0.23 ± 0.03 km3 to 0.16 ± 0.02 km3 (-30.4%) and from 0.27 ± 0.02 km3 to 0.24 ± 0.01 km3 (-10.6%), respectively. The mean surface elevation decreased by 8.5±2.8 and 10.1 ±2.8m. The average areal (~0.048-0.011 km2a-1) and volumetric (~0.003−0.001 km3 a-1) changes are higher than the majority of other estimates from Antarctic Peninsula glaciers.


2009 ◽  
Vol 55 (191) ◽  
pp. 453-460 ◽  
Author(s):  
Andrea Fischer

AbstractIn order to develop and evaluate a method for the determination of glacier volume from ice-thickness data, the volume of Schaufelferner, Austria, is calculated (1) by manual interpolation of ground-penetrating radar (GPR) data based on measurements at 36 locations in 1995, (2) by manual interpolation of 144 GPR measurements acquired for a higher-resolution estimate in 2003 and 2006, (3) by multiplying the mean of the measured ice-thickness data by the glacier area, (4) by automatic kriging of the 1995 GPR data and (5) by application of area/volume scaling algorithms to the Austrian glacier inventory data of 1969, 1997 and 2006. The so determined glacier volumes are compared with the ice-volume changes calculated from digital elevation models (DEMs) of the Austrian glacier inventories. The manually interpolated volumes based on the 1995 and 2003/06 GPR data yielded a volume loss only slightly different from volume loss calculated from the glacier inventories of 1997 and 2007. Other methods were not able to reproduce the volume losses of the glacier inventory DEMs. To assess the accuracy of deriving ice-thickness changes with GPR, repeated ice-thickness measurements at the same locations were carried out between 2005 and 2008.


2021 ◽  
pp. 1-19
Author(s):  
Melchior Grab ◽  
Enrico Mattea ◽  
Andreas Bauder ◽  
Matthias Huss ◽  
Lasse Rabenstein ◽  
...  

Abstract Accurate knowledge of the ice thickness distribution and glacier bed topography is essential for predicting dynamic glacier changes and the future developments of downstream hydrology, which are impacting the energy sector, tourism industry and natural hazard management. Using AIR-ETH, a new helicopter-borne ground-penetrating radar (GPR) platform, we measured the ice thickness of all large and most medium-sized glaciers in the Swiss Alps during the years 2016–20. Most of these had either never or only partially been surveyed before. With this new dataset, 251 glaciers – making up 81% of the glacierized area – are now covered by GPR surveys. For obtaining a comprehensive estimate of the overall glacier ice volume, ice thickness distribution and glacier bed topography, we combined this large amount of data with two independent modeling algorithms. This resulted in new maps of the glacier bed topography with unprecedented accuracy. The total glacier volume in the Swiss Alps was determined to be 58.7 ± 2.5 km3 in the year 2016. By projecting these results based on mass-balance data, we estimated a total ice volume of 52.9 ± 2.7 km3 for the year 2020. Data and modeling results are accessible in the form of the SwissGlacierThickness-R2020 data package.


2009 ◽  
Vol 40 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Nils Granlund ◽  
Angela Lundberg ◽  
James Feiccabrino ◽  
David Gustafsson

Ground penetrating radar operated from helicopters or snowmobiles is used to determine snow water equivalent (SWE) for annual snowpacks from radar wave two-way travel time. However, presence of liquid water in a snowpack is known to decrease the radar wave velocity, which for a typical snowpack with 5% (by volume) liquid water can lead to an overestimation of SWE by about 20%. It would therefore be beneficial if radar measurements could also be used to determine snow wetness. Our approach is to use radar wave attenuation in the snowpack, which depends on electrical properties of snow (permittivity and conductivity) which in turn depend on snow wetness. The relationship between radar wave attenuation and these electrical properties can be derived theoretically, while the relationship between electrical permittivity and snow wetness follows a known empirical formula, which also includes snow density. Snow wetness can therefore be determined from radar wave attenuation if the relationship between electrical conductivity and snow wetness is also known. In a laboratory test, three sets of measurements were made on initially dry 1 m thick snowpacks. Snow wetness was controlled by stepwise addition of water between radar measurements, and a linear relationship between electrical conductivity and snow wetness was established.


2016 ◽  
Vol 62 (236) ◽  
pp. 1008-1020 ◽  
Author(s):  
J.J. LAPAZARAN ◽  
J. OTERO ◽  
A. MARTÍN-ESPAÑOL ◽  
F.J. NAVARRO

ABSTRACTThis is the first (Paper I) of three companion papers focused respectively, on the estimates of the errors in ice thickness retrieved from pulsed ground-penetrating radar (GPR) data, on how to estimate the errors at the grid points of an ice-thickness DEM, and on how the latter errors, plus the boundary delineation errors, affect the ice-volume estimates. We here present a comprehensive analysis of the various errors involved in the computation of ice thickness from pulsed GPR data, assuming they have been properly migrated. We split the ice-thickness error into independent components that can be estimated separately. We consider, among others, the effects of the errors in radio-wave velocity and timing. A novel aspect is the estimate of the error in thickness due to the uncertainty in horizontal positioning of the GPR measurements, based on the local thickness gradient. Another novel contribution is the estimate of the horizontal positioning error of the GPR measurements due to the velocity of the GPR system while profiling, and the periods of GPS refreshing and GPR triggering. Their effects are particularly important for airborne profiling. We illustrate our methodology through a case study of Werenskioldbreen, Svalbard.


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