scholarly journals Ice thickness distribution of all Swiss glaciers based on extended ground-penetrating radar data and glaciological modeling

2021 ◽  
pp. 1-19
Author(s):  
Melchior Grab ◽  
Enrico Mattea ◽  
Andreas Bauder ◽  
Matthias Huss ◽  
Lasse Rabenstein ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Thickness Distribution ◽  
Radar Data ◽  
Tourism Industry ◽  
Swiss Alps ◽  
Ice Thickness ◽  
Hazard Management ◽  
Bed Topography ◽  
Ice Volume ◽  
Ground Penetrating

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.

scholarly journals On the errors involved in ice-thickness estimates I: ground-penetrating radar measurement errors

2016 ◽  
Vol 62 (236) ◽  
pp. 1008-1020 ◽  
Author(s):  
J.J. LAPAZARAN ◽  
J. OTERO ◽  
A. MARTÍN-ESPAÑOL ◽  
F.J. NAVARRO
Keyword(s):  
Ground Penetrating Radar ◽  
Measurement Errors ◽  
Ice Thickness ◽  
Independent Components ◽  
Ice Volume ◽  
Thickness Error ◽  
Grid Points ◽  
Ground Penetrating ◽  
Volume Estimates

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.

scholarly journals Pervasive cold ice within a temperate glacier – implications for glacier thermal regimes, sediment transport and foreland geomorphology

2019 ◽  
Vol 13 (3) ◽  
pp. 827-843 ◽  
Author(s):  
Benedict T. I. Reinardy ◽  
Adam D. Booth ◽  
Anna L. C. Hughes ◽  
Clare M. Boston ◽  
Henning Åkesson ◽  
...  
Keyword(s):  
Climate Warming ◽  
Ground Penetrating Radar ◽  
Radar Data ◽  
Ice Thickness ◽  
Systematic Mapping ◽  
Ablation Area ◽  
Seasonal Snow ◽  
Thermal Regimes ◽  
Subglacial Topography ◽  
Ground Penetrating

Abstract. This study suggests that cold-ice processes may be more widespread than previously assumed, even within temperate glacial systems. We present the first systematic mapping of cold ice at the snout of the temperate glacier Midtdalsbreen, an outlet of the Hardangerjøkulen icefield (Norway), from 43 line kilometres of ground-penetrating radar data. Results show a 40 m wide cold-ice zone within the majority of the glacier snout, where ice thickness is <10 m. We interpret ice to be cold-based across this zone, consistent with basal freeze-on processes involved in the deposition of moraines. We also find at least two zones of cold ice up to 15 m thick within the ablation area, occasionally extending to the glacier bed. There are two further zones of cold ice up to 30 m thick in the accumulation area, also extending to the glacier bed. Cold-ice zones in the ablation area tend to correspond to areas of the glacier that are covered by late-lying seasonal snow patches that reoccur over multiple years. Subglacial topography and the location of the freezing isotherm within the glacier and underlying subglacial strata likely influence the transport and supply of supraglacial debris and formation of controlled moraines. The wider implication of this study is the possibility that, with continued climate warming, temperate environments with primarily temperate glaciers could become polythermal in forthcoming decades with (i) persisting thinning and (ii) retreat to higher altitudes where subglacial permafrost could be and/or become more widespread. Adversely, the number and size of late-lying snow patches in ablation areas may decrease and thereby reduce the extent of cold ice, reinforcing the postulated change in the thermal regime.

scholarly journals Determination of total ice volume and ice-thickness distribution of two glaciers in the Hohe Tauern region, Eastern Alps, from GPR data

2009 ◽  
Vol 50 (51) ◽  
pp. 71-79 ◽  
Author(s):  
D. Binder ◽  
E. Brückl ◽  
K.H. Roch ◽  
M. Behm ◽  
W. Schöner ◽  
...  
Keyword(s):  
Thickness Distribution ◽  
Eastern Alps ◽  
Spatial Density ◽  
Ice Thickness ◽  
Validation Data ◽  
Ice Volume ◽  
Bedrock Topography ◽  
Glacier System ◽  
Ground Penetrating

AbstractGlobal warming is causing an apparent rapid retreat of many glaciers worldwide. In addition to mass-balance investigation, the determination and monitoring of total glacial ice volume and ice-thickness distribution are important parameters for understanding the interactions between climate and the complex glacier system. Because of spatially irregular and sparse datasets, scaling of volume and ice-thickness distribution is often a challenging problem. This study focuses on two small (<2 km2) temperate glaciers in the Hohe Tauern (Eastern Alps) region of central Austria. The period 2003–04 saw the first use of ground-penetrating radar (GPR) to determine the total ice volume and ice-thickness distribution of the two glaciers. A centre frequency of 20 MHz was used in point measuring mode. Despite variable data quality, bedrock reflections up to depths of >100m were identified in the data. The acquired GPR data are irregularly distributed and the spatial density is too low to calculate reasonable bedrock topography with standard interpolation approaches. Thus one main focus of this study was to develop an appropriate interpolation technique. Eventually, kriging technique and a glacial mechanically based interpolation parameter were used. Mean calculated ice thicknesses for the two investigated glaciers are 40–50 m, with a maximum of 150–165 m. No direct validation data are available, so different considerations support the computed bedrock topography.

scholarly journals Ice volume distribution and implications on runoff projections in a glacierized catchment

2012 ◽  
Vol 9 (6) ◽  
pp. 7507-7541 ◽  
Author(s):  
J. Gabbi ◽  
D. Farinotti ◽  
A. Bauder ◽  
H. Maurer
Keyword(s):  
Thickness Distribution ◽  
Regional Climate ◽  
Accurate Determination ◽  
Annual Runoff ◽  
Ice Thickness ◽  
Volume Distribution ◽  
Ice Volume ◽  
Runoff Decrease ◽  
Ground Penetrating ◽  
Thickness Measurements

Abstract. A dense network of helicopter-based ground penetrating radar (GPR) measurements was used to determine the ice-thickness distribution in the Mauvoisin region. The comprehensive set of ice-thickness measurements was combined with an ice-thickness estimation approach for an accurate determination of the bedrock. A total ice volume of 3.69 ± 0.11 km3 and a maximum ice-thickness of 290 m were found. The ice-thickness values were then employed as input for a combined glacio-hydrological model forced by most recent regional climate scenarios. This model provided glacier evolution and runoff projections. Runoff projections of the measured initial ice volume distribution show an increase in annual runoff of 4% in the next two decades, followed by a persistent runoff decrease until 2100. Finally, we checked the influence of the ice thickness distribution on runoff projections. Our analyses revealed that reliable estimates of the ice volume is essential. Wrong estimations of the total ice volume might even lead to deviations of the predicted general runoff trend.

scholarly journals Targeted reflection-waveform inversion of experimental ground-penetrating radar data for quantification of oil spills under sea ice

Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. WA59-WA70 ◽  
Author(s):  
John H. Bradford ◽  
Esther L. Babcock ◽  
Hans-Peter Marshall ◽  
David F. Dickins
Keyword(s):  
Sea Ice ◽  
Ground Penetrating Radar ◽  
Oil Spills ◽  
Waveform Inversion ◽  
Radar Data ◽  
The Arctic ◽  
Ice Thickness ◽  
Inversion Algorithm ◽  
Control Value ◽  
Ground Penetrating

Rapid spill detection and mapping are needed with increasing levels of oil exploration and production in the Arctic. Previous work has found that ground-penetrating radar (GPR) is effective for qualitative identification of oil spills under, and encapsulated within, sea ice. Quantifying the spill distribution will aid effective spill response. To this end, we have developed a targeted GPR reflection-waveform inversion algorithm to quantify the geometry of oil spills under and within sea ice. With known electric properties of the ice and oil, we have inverted for oil thickness and variations in ice thickness. We have tested the algorithm with data collected during a controlled spill experiment using 500-MHz radar reflection data. The algorithm simultaneously recovered the thickness of a 5-cm-thick oil layer at the base of the ice to within 8% of the control value, estimated the thickness of a 1-cm-thick oil layer encapsulated within the ice to within 30% of the control value, and accurately mapped centimeter-scale variations in ice thickness.

scholarly journals Ice thickness, areal and volumetric changes of Davies Dome and Whisky Glacier (James Ross Island, Antarctic Peninsula) in 1979–2006

2012 ◽  
Vol 58 (211) ◽  
pp. 904-914 ◽  
Author(s):  
Zbynĕk Engel ◽  
Daniel Nývlt ◽  
Kamil Láska
Keyword(s):  
Antarctic Peninsula ◽  
Ground Penetrating Radar ◽  
Ice Thickness ◽  
Bed Topography ◽  
Ice Cap ◽  
Valley Glacier ◽  
Elevation Changes ◽  
James Ross Island ◽  
The Mean ◽  
Ground Penetrating

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.

scholarly journals Ice volume distribution and implications on runoff projections in a glacierized catchment

2012 ◽  
Vol 16 (12) ◽  
pp. 4543-4556 ◽  
Author(s):  
J. Gabbi ◽  
D. Farinotti ◽  
A. Bauder ◽  
H. Maurer
Keyword(s):  
Thickness Distribution ◽  
Regional Climate ◽  
Accurate Determination ◽  
Annual Runoff ◽  
Ice Thickness ◽  
Volume Distribution ◽  
Ice Volume ◽  
Runoff Decrease ◽  
Ground Penetrating ◽  
Thickness Measurements

Abstract. A dense network of helicopter-based ground-penetrating radar (GPR) measurements was used to determine the ice-thickness distribution in the Mauvoisin region. The comprehensive set of ice-thickness measurements was combined with an ice-thickness estimation approach for an accurate determination of the bedrock. A total ice volume of 3.69 ± 0.31 km3 and a maximum ice thickness of 290 m were found. The ice-thickness values were then employed as input for a combined glacio-hydrological model forced by most recent regional climate scenarios. This model provided glacier evolution and runoff projections for the period 2010–2100. Runoff projections of the measured initial ice volume distribution show an increase in annual runoff of 4% in the next two decades, followed by a persistent runoff decrease until 2100. Finally, we checked the influence of the ice-thickness distribution on runoff projections. Our analyses revealed that reliable estimates of the ice volume are essential for modelling future glacier and runoff evolution. Wrong estimations of the total ice volume might even lead to deviations of the predicted general runoff trend.

scholarly journals 50 MHz helicopter-borne radar data for determination of glacier thermal regime in the central Chilean Andes

2015 ◽  
Vol 56 (70) ◽  
pp. 193-201 ◽  
Author(s):  
Guisella Gacitúa ◽  
José A. Uribe ◽  
Ryan Wilson ◽  
Thomas Loriaux ◽  
Jorge Hernández ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Radar Data ◽  
Ice Thickness ◽  
Ice Dynamics ◽  
Central Chile ◽  
Glacier Ice ◽  
Ground Penetrating ◽  
Further Development ◽  
Chilean Andes

AbstractDespite their importance as freshwater reservoirs for downstream river systems, few glaciers in central Chile have been comprehensively surveyed. This study presents ground-penetrating radar (GPR) and field-based observations for characterizing the englacial and basal conditions of Glaciar Olivares Alfa (33°110 S, 70°130 W), central Chilean Andes. Using a 50 MHz radar mounted onto a helicopter platform, data were collected covering large portions of the glacier accumulation and ablation zones. The radar data revealed boundaries of a temperate-ice layer at the base of the eastern body of Glaciar Olivares Alfa which appears to be covered by colder ice that extends throughout large parts of the glacier. The thickness of the temperate ice layer is highly variable across the glacier, being on average 40% of the total ice thickness. Radar data analyses reveal regions of cold ice at the bottom/base of the glacier and also patterns of highly saturated sediments beneath the glacier. Using GPR data, this study represents the most exhaustive analysis of glacier ice structure performed in the central Chilean Andes. The results will enable improved estimations of the glacier’s mass balance and ice dynamics, helping us to understand its further development and its impact on water availability.

scholarly journals Spatial distribution of cold-ice within a temperate glacier – implications for glacier dynamics, sediment transport and foreland geomorphology

2018 ◽  
Author(s):  
Benedict T. I. Reinardy ◽  
Adam Booth ◽  
Anna Hughes ◽  
Clare M. Boston ◽  
Henning Åkesson ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sediment Transport ◽  
Ground Penetrating Radar ◽  
Radar Data ◽  
Ice Thickness ◽  
Direct Observations ◽  
Glacier Dynamics ◽  
Ground Penetrating

Abstract. This study suggests that cold-ice processes may be more widespread even within temperate glacial systems, than previously assumed. We present the first direct observations of cold-ice at the snout of the temperate glacier Midtdalsbreen an outlet of the Hardangerjøkulen icefield (Norway) from 43 line-kilometres of ground penetrating radar data. Results show a 40 m-wide cold-ice zone within the majority of the glacier snout, where ice thickness is

scholarly journals Ice volume and basal topography estimation using geostatistical methods and ground-penetrating radar measurements: application to the Tsanfleuron and Scex Rouge glaciers, Swiss Alps

2021 ◽  
Vol 15 (11) ◽  
pp. 5169-5186
Author(s):  
Alexis Neven ◽  
Valentin Dall'Alba ◽  
Przemysław Juda ◽  
Julien Straubhaar ◽  
Philippe Renard
Keyword(s):  
Ground Penetrating Radar ◽  
Volume Estimation ◽  
Swiss Alps ◽  
Data Set ◽  
Mountain Glacier ◽  
Ice Volume ◽  
Bedrock Topography ◽  
Direct Sampling ◽  
Ground Penetrating ◽  
Geomorphological Features

Abstract. Ground-penetrating radar (GPR) is widely used for determining mountain glacier thickness. However, this method provides thickness data only along the acquisition lines, and therefore interpolation has to be made between them. Depending on the interpolation strategy, calculated ice volumes can differ and can lack an accurate error estimation. Furthermore, glacial basal topography is often characterized by complex geomorphological features, which can be hard to reproduce using classical interpolation methods, especially when the field data are sparse or when the morphological features are too complex. This study investigates the applicability of multiple-point statistics (MPS) simulations to interpolate glacier bedrock topography using GPR measurements. In 2018, a dense GPR data set was acquired on the Tsanfleuron Glacier (Switzerland). These data were used as the source for a bedrock interpolation. The results obtained with the direct-sampling MPS method are compared against those obtained with kriging and sequential Gaussian simulations (SGSs) on both a synthetic data set – with known reference volume and bedrock topography – and the real data underlying the Tsanfleuron Glacier. Using the MPS modeled bedrock, the ice volume for the Scex Rouge and Tsanfleuron glaciers is estimated to be 113.9 ± 1.6 million cubic meters. The direct-sampling approach, unlike the SGS and kriging, allowed not only an accurate volume estimation but also the generation of a set of realistic bedrock simulations. The complex karstic geomorphological features are reproduced and can be used to significantly improve for example the precision of subglacial flow estimation.

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