Glacier Ice Thickness Estimation and Future Lake Formation in Swiss Southwestern Alps—The Upper Rhône Catchment: A VOLTA Application

Glacial lake formations are currently being observed in the majority of glacierized mountains in the world. Given the ongoing climate change and population increase, studying glacier ice thickness and bed topography is a necessity for understanding the erosive power of glacier activity in the past and lake formation in the future. This study uses the available information to predict potential sites for future lake formation in the Upper Rhône catchment located in the Southwestern Swiss Alps. The study integrates the latest available glacier outlines and high-quality digital elevation models (DEMs) into the Volume and Topography Automation (VOLTA) model to estimate ice thickness within the extent of the glaciers. Unlike the previous ice thickness models, VOLTA calculates ice thickness distribution based on automatically-derived centerlines, while optimizing the model by including the valley side drag parameter in the force equation. In this study, a total ice volume of 37.17 ± 12.26 km3 (1σ) was estimated for the Upper Rhône catchment. The comparison of VOLTA performance indicates a stronger relationship between measured and predicted bedrock, confirming the less variability in VOLTA’s results (r2 ≈ 0.92) than Glacier Bed Topography (GlabTop) (r2 ≈ 0.82). Overall, the mean percentage of ice thickness error for all measured profiles in the Upper Rhône catchment is around ±22%, of which 28 out of 42 glaciers are underestimated. By incorporating the vertical accuracy of free-ice DEM, we could identify 171 overdeepenings. Among them, 100 sites have a high potential for future lake formation based on four morphological criteria. The visual evaluation of deglaciated areas also supports the robustness of the presented methodology, as 11 water bodies were already formed within the predicted overdeepenings. In the wake of changing global climate, such results highlight the importance of combined datasets and parameters for projecting the future glacial landscapes. The timely information on future glacial lake formation can equip planners with essential knowledge, not only for managing water resources and hazards, but also for understanding glacier dynamics, catchment ecology, and landscape evolution of high-mountain regions.

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

Journal of Glaciology ◽

10.1017/jog.2021.55 ◽

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.

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A multi-level strategy for anticipating future glacier lake formation and associated hazard potentials

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-339-2010 ◽

2010 ◽

Vol 10 (2) ◽

pp. 339-352 ◽

Cited By ~ 96

Author(s):

H. Frey ◽

W. Haeberli ◽

A. Linsbauer ◽

C. Huggel ◽

F. Paul

Keyword(s):

Swiss Alps ◽

Bed Topography ◽

Aster Gdem ◽

Digital Elevation ◽

Lake Formation ◽

Level 3 ◽

Multi Level ◽

Four Levels ◽

Elevation Model

Abstract. In the course of glacier retreat, new glacier lakes can develop. As such lakes can be a source of natural hazards, strategies for predicting future glacier lake formation are important for an early planning of safety measures. In this article, a multi-level strategy for the identification of overdeepened parts of the glacier beds and, hence, sites with potential future lake formation, is presented. At the first two of the four levels of this strategy, glacier bed overdeepenings are estimated qualitatively and over large regions based on a digital elevation model (DEM) and digital glacier outlines. On level 3, more detailed and laborious models are applied for modeling the glacier bed topography over smaller regions; and on level 4, special situations must be investigated in-situ with detailed measurements such as geophysical soundings. The approaches of the strategy are validated using historical data from Trift Glacier, where a lake formed over the past decade. Scenarios of future glacier lakes are shown for the two test regions Aletsch and Bernina in the Swiss Alps. In the Bernina region, potential future lake outbursts are modeled, using a GIS-based hydrological flow routing model. As shown by a corresponding test, the ASTER GDEM and the SRTM DEM are both suitable to be used within the proposed strategy. Application of this strategy in other mountain regions of the world is therefore possible as well.

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Recent Changes of Glacial Lakes in the High Mountain Asia and Its Potential Controlling Factors Analysis

Remote Sensing ◽

10.3390/rs13183757 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3757

Author(s):

Meimei Zhang ◽

Fang Chen ◽

Hang Zhao ◽

Jinxiao Wang ◽

Ning Wang

Keyword(s):

Google Earth ◽

Controlling Factors ◽

Rapid Expansion ◽

Expansion Rate ◽

Glacial Lake ◽

High Mountain ◽

Glacial Lakes ◽

Computing Platform ◽

Glacier Ice ◽

Landsat Satellite

The current glacial lake datasets in the High Mountain Asia (HMA) region still need to be improved because their boundary divisions in the land–water transition zone are not precisely delineate, and also some very small glacial lakes have been lost due to their mixed reflectance with backgrounds. In addition, most studies have only focused on the changes in the area of a glacial lake as a whole, but do not involve the actual changes of per pixel on its boundary and the potential controlling factors. In this research, we produced more accurate and complete maps of glacial lake extent in the HMA in 2008, 2012, and 2016 with consistent time intervals using Landsat satellite images and the Google Earth Engine (GEE) cloud computing platform, and further studied the formation, distribution, and dynamics of the glacial lakes. In total, 17,016 and 21,249 glacial lakes were detected in 2008 and 2016, respectively, covering an area of 1420.15 ± 232.76 km2 and 1577.38 ± 288.82 km2; the lakes were mainly located at altitudes between 4400 m and 5600 m. The annual areal expansion rate was approximately 1.38% from 2008 to 2016. To explore the cause of the rapid expansion of individual glacial lakes, we investigated their long-term expansion rates by measuring changes in shoreline positions. The results show that glacial lakes are expanding rapidly in areas close to glaciers and had a high expansion rate of larger than 20 m/yr from 2008 to 2016. Glacial lakes in the Himalayas showed the highest expansion rate of more than 2 m/yr, followed by the Karakoram Mountains (1.61 m/yr) and the Tianshan Mountains (1.52 m/yr). The accelerating rate of glacier ice and snow melting caused by global warming is the primary contributor to glacial lake growth. These results may provide information that will help in the understanding of detailed lake dynamics and the mechanism, and also facilitate the scientific recognition of the potential hazards associated with glacial lakes in this region.

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Correction: Gharehchahi, S.; James, W.H.M.; Bhardwaj, A.; Jensen, J.L.R.; Sam, L.; Ballinger, T.J.; Butler, D.R. Glacier Ice Thickness Estimation and Future Lake Formation in Swiss Southwestern Alps—The Upper Rhône Catchment: A VOLTA Application. Remote Sens. 2020, 12, 3443

Remote Sensing ◽

10.3390/rs12223709 ◽

2020 ◽

Vol 12 (22) ◽

pp. 3709

Author(s):

Saeideh Gharehchahi ◽

William H. M. James ◽

Anshuman Bhardwaj ◽

Jennifer L. R. Jensen ◽

Lydia Sam ◽

...

Keyword(s):

Ice Thickness ◽

Thickness Estimation ◽

Lake Formation ◽

Glacier Ice ◽

Southwestern Alps

The authors wish to make the following corrections to this paper [...]

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Glacial Lake Invermere, upper Columbia River valley, British Columbia: a paleogeographic reconstruction

Canadian Journal of Earth Sciences ◽

10.1139/e92-059 ◽

1992 ◽

Vol 29 (4) ◽

pp. 687-692 ◽

Cited By ~ 5

Author(s):

Oswald Sawicki ◽

Derald G. Smith

Keyword(s):

British Columbia ◽

Rocky Mountain ◽

Columbia River ◽

Water Bodies ◽

Glacial Lake ◽

Ice Thickness ◽

Valley Fill ◽

Northerly Direction ◽

Glacier Ice ◽

Late Wisconsinan

Terraces of thick lacustrine silt and deltaic gravel flank parts of the valley floor of the Rocky Mountain Trench between Skookumchuck and Donald, British Columbia. These indicate the presence of former Late Wisconsinan glacial Lake Invermere, which at its maximum extent occupied the Rocky Mountain Trench from Bluewater Creek, 6 km north of Donald, to 7 km north of Skookumchuck. The lake was 210 km long, an average of 2.5 km wide by 100 m deep, and had an area of 530 km2. Retreating glacier ice is interpreted to have formed a dam at the northern end of the lake, and blockage to the south resulted from a sediment valley fill.Glacial Lake Invermere formed as two water bodies, at elevations 885 and 900 m asl, separated by glacier ice. These two water bodies later joined to form a continuous lake at 835 m asl. Evidence of isostatic tilting is absent, suggesting uniform ice thickness and thinning, a pattern contrary to that inferred for other areas of southern British Columbia. After breaching of the valley fill at its south end, the lake terminated with final melting of Rocky Mountain Trench ice. At that time the southerly flow of water reversed to a northerly direction. A radiocarbon date from an adjacent valley indicates the lake drained prior to 10 000 BP.

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Modelling glacier-bed overdeepenings and possible future lakes for the glaciers in the Himalaya—Karakoram region

Annals of Glaciology ◽

10.3189/2016aog71a627 ◽

2016 ◽

Vol 57 (71) ◽

pp. 119-130 ◽

Cited By ~ 55

Author(s):

A. Linsbauer ◽

H. Frey ◽

W. Haeberli ◽

H. Machguth ◽

M.F. Azam ◽

...

Keyword(s):

Ice Thickness ◽

Surface Slope ◽

Bed Topography ◽

Bed Elevation ◽

Digital Elevation ◽

Surface Slopes ◽

Lake Formation ◽

Topography Model ◽

Basal Shear ◽

The Himalaya

AbstractSurface digital elevation models (DEMs) and slope-related estimates of glacier thickness enable modelling of glacier-bed topographies over large ice-covered areas. Due to the erosive power of glaciers, such bed topographies can contain numerous overdeepenings, which when exposed following glacier retreat may fill with water and form new lakes. In this study, the bed overdeepenings for ~28 000 glaciers (40 775 km2) of the Himalaya-Karakoram region are modelled using GlabTop2 (Glacier Bed Topography model version 2), in which ice thickness is inferred from surface slope by parameterizing basal shear stress as a function of elevation range for each glacier. The modelled ice thicknesses are uncertain (±30%), but spatial patterns of ice thickness and bed elevation primarily depend on surface slopes as derived from the DEM and, hence, are more robust. About 16 000 overdeepenings larger than 104m2 were detected in the modelled glacier beds, covering an area of ~2200 km2 and having a volume of ~120km3 (3-4% of present-day glacier volume). About 5000 of these overdeepenings (1800 km2) have a volume larger than 106m3. The results presented here are useful for anticipating landscape evolution and potential future lake formation with associated opportunities (tourism, hydropower) and risks (lake outbursts).

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Recent and future warm extreme events and high-mountain slope stability

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0078 ◽

2010 ◽

Vol 368 (1919) ◽

pp. 2435-2459 ◽

Cited By ~ 100

Author(s):

C. Huggel ◽

N. Salzmann ◽

S. Allen ◽

J. Caplan-Auerbach ◽

L. Fischer ◽

...

Keyword(s):

Slope Stability ◽

Climate Models ◽

Swiss Alps ◽

High Mountain ◽

Temperature Pattern ◽

European Alps ◽

High Mountains ◽

Slope Failures ◽

Recent Climate ◽

The Future

The number of large slope failures in some high-mountain regions such as the European Alps has increased during the past two to three decades. There is concern that recent climate change is driving this increase in slope failures, thus possibly further exacerbating the hazard in the future. Although the effects of a gradual temperature rise on glaciers and permafrost have been extensively studied, the impacts of short-term, unusually warm temperature increases on slope stability in high mountains remain largely unexplored. We describe several large slope failures in rock and ice in recent years in Alaska, New Zealand and the European Alps, and analyse weather patterns in the days and weeks before the failures. Although we did not find one general temperature pattern, all the failures were preceded by unusually warm periods; some happened immediately after temperatures suddenly dropped to freezing. We assessed the frequency of warm extremes in the future by analysing eight regional climate models from the recently completed European Union programme ENSEMBLES for the central Swiss Alps. The models show an increase in the higher frequency of high-temperature events for the period 2001–2050 compared with a 1951–2000 reference period. Warm events lasting 5, 10 and 30 days are projected to increase by about 1.5–4 times by 2050 and in some models by up to 10 times. Warm extremes can trigger large landslides in temperature-sensitive high mountains by enhancing the production of water by melt of snow and ice, and by rapid thaw. Although these processes reduce slope strength, they must be considered within the local geological, glaciological and topographic context of a slope.

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Ice thickness measurements of the debris covered Ngozumpa glacier, Nepal

10.5194/egusphere-egu2020-19854 ◽

2020 ◽

Author(s):

Lindsey Nicholson ◽

Fabien Maussion ◽

Christoph Mayer ◽

Hamish Pritchard ◽

Astrid Lambrecht ◽

...

Keyword(s):

Field Measurements ◽

Rate Of Change ◽

Ice Thickness ◽

High Mountain ◽

Global Consensus ◽

Glacier Ice ◽

Radar Measurements ◽

Global Sea Level ◽

Ground Penetrating ◽

Thickness Measurements

The presence of extensive debris cover on glaciers in parts of High Mountain Asia increases the certainty about the present day amount of ice, its ongoing rate of change and resultant impact on global sea level rise, regional water and local hazards Here we use ground penetrating radar measurements of ice thickness for the Ngozumpa glacier, a large debris-covered glacier in Nepal, to explore the challenges of using such data to calculate glacier volume, and to compare how these field measurements compare to the modelled glacier thickness for this glacier generated by the four models used in the global consensus glacier ice thickness dataset, which suggested the region holds 27% less ice than previous estimates (Farinotti and others, 2019). We also compare&#160;the ice thickness measured at Ngozumpa glacier to existing data from the smaller neighboring Khumbu glacier and evaluate the maximum volume of a possible moraine dammed lake at this site.

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Assessment of glacier lakes development in Central Caucasus

10.5194/egusphere-egu2020-6471 ◽

2020 ◽

Author(s):

Ivan Lavrentiev ◽

Dmitry Petrakov ◽

Stanislav Kutuzov ◽

Andrey Smirnov

Keyword(s):

Growth Potential ◽

Ice Thickness ◽

Topographic Map ◽

Model Errors ◽

Bed Topography ◽

Subglacial Lake ◽

Flow Formation ◽

Lake Formation ◽

Central Caucasus ◽

Rfbr Grant

Glacier mass loss and consequent termini retreat lead to formation and growth of glacier lakes. In the Mt. Elbrus region, outbursts of lakes formed in recent decades have led to human casualties and significant damage. Building codes of Russian Federation on engineering surveys do not regulate the possibility of glacier lake formation in front of retreating glaciers, which can lead to errors in the future engineering design. Using ground based and airborne GPR data, as well as global ice thickness models, we have identified areas of potential lake formation on glacier bed for a number of glaciers in the Mt. Elbrus region. The method was tested by retrospective modeling for Bolshoy Azau and Djikiugankez glaciers bed topography on the base of 1957 topographic map. In the areas where glaciers disappeared by 2017, out of 13 simulated closed bed depressions 7 existing lakes were predicted by the hydraulic potential. 6 closed depressions on Djikiugankez glacier bed as of 1957 are currently absent, which might be related to the model uncertainties and the original DEMs errors, as well as to possible filling of lakes by sediments. Retrospective modeling of the Bashkara glacier bed topography based on SRTM DEM (2000) showed significant growth potential of the lake Lapa. Retrospective modeling of the Kaayarty glacier bed topography has not provided a clear answer about the possibility if subglacial lake outburst flood was a trigger for catastrophic debris flow formation during the summer of 2000.In case of total disappearance of Bolshoy Azau, Djikiugankez and Bashkara glaciers at least 11 new lakes with total area of about 1.7 km2 and an average depth of 8 m will form. While the deepest lake will appear in ablation zone of Bolshoy Azau glacier (at elevation 3100-3400 m a.s.l.) the largest in area (1 km2) glacial lake will be formed at the Djikiugankez snout with maximum depth of 40 m and mean depth of 7.2 m. The simulation also showed that in the present conditions, glacier bed lakes of different number and size may also exist under studied glaciers. Our estimates may contain uncertainties due to low resolution of airborne GPR data and the lack of GPR data for Kaayarty glacier, DEM and ice thickness model errors. Detailed ground-based radar survey planned for the summer 2020 will enable the assessment of the size and volume of the potential lakes under Bolshoy Azau glacier.This work was funded by RFBR grant No. 18-05-00520.

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Glacier-permafrost relations in a high-mountain environment: 5 decades of kinematic monitoring at the Gruben site, Swiss Alps

10.5194/tc-2021-208 ◽

2021 ◽

Author(s):

Isabelle Gärtner-Roer ◽

Nina Brunner ◽

Reynald Delaloye ◽

Wilfried Haeberli ◽

Andreas Kääb ◽

...

Keyword(s):

Mass Loss ◽

Time Scale ◽

Ground Surface ◽

Satellite System ◽

Swiss Alps ◽

Aerial Images ◽

High Mountain ◽

Frozen Ground ◽

Glacier Tongue ◽

Glacier Ice

Abstract. Digitized aerial images were used to monitor the evolution of perennially frozen debris and polythermal glacier ice at the intensely investigated Gruben site in the Swiss Alps over a period of about 50 years. The photogrammetric analysis allowed for a compilation of detailed spatio-temporal information on flow velocities and thickness changes. In addition, high-resolution GNSS (Global Navigation Satellite System) and ground-surface temperature measurements were included in the analysis to provide insight into short-term changes. Over time, extremely contrasting developments and landform responses are documented. Viscous flow within the warming and already near-temperate rockglacier permafrost continued at a constant average but seasonally variable speed of typically decimetres per year, with low average surface lowering of centimeters to decimetres per year. This quite constant flow causes the continued advance of the characteristic convex, lava stream-like rockglacier with its over-steepened fronts. Thawing rates of ice-rich perennially frozen ground to strong climate forcing are obviously very low (centimetres per year) and the dynamic response strongly delayed (time scale decades to centuries). The adjacent cold debris-covered glacier tongue remained an essentially concave landform with diffuse margins, predominantly chaotic surface structure, intermediate thickness losses (decimetre per year) and clear signs of down-wasting and decreasing flow velocity. The former contact zone between the cold glacier margin and the upper part of the rockglacier with remains of buried glacier ice embedded on top of frozen debris exhibits complex phenomena of thermokarst in massive ice and backflow towards the topographic depression produced by the retreating glacier tongue. As is typical for glaciers in the Alps, the clean glacier part shows a rapid response (time scale years) to strong climatic forcing with spectacular retreat (> 10 meters per year) and mass loss (up to > 1 meter water equivalent specific mass loss per year). The system of periglacial lakes shows a correspondingly dynamic evolution and had to be controlled by engineering work for hazard protection.

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