Estimation of volume changes of mountain glaciers from ICESat data: an example from the Aletsch Glacier, Swiss Alps

Abstract. Worldwide estimation of recent changes in glacier volume is challenging, but becomes more feasible with the help of present and future remote sensing missions. NASA's Ice Cloud and Elevation Satellite (ICESat) mission provides accurate elevation estimates derived from the two way travel time of the emitted laser pulse. In this study two different methods were employed for derivation of surface elevation changes from ICESat records on example of the Aletsch Glacier. A statistical approach relies on elevation differences of ICESat points to a reference DEM while an analytical approach compares spatially similar ICESat tracks. Using the statistical approach, in the upper and lower parts of the ablation area, the surface lowering was found to be from −2.1 ± 0.15 m yr−1 to −2.6 ± 0.10 m yr−1 and from −3.3 ± 0.36 m yr−1 to −5.3 ± 0.39 m yr−1, respectively, depending on the DEM used. Employing the analytical method, the surface lowering in the upper part of the ablation area was estimated as −2.5 ± 1.3 m yr−1 between 2006 and 2009. In the accumulation area both methods revealed no significant trend. The trend in surface lowering derived by the statistical method allows an estimation of the mean mass balance in the period 2003–2009 assuming constant ice density and a linear change of glacier surface lowering with altitude in the ablation area. The resulting mass balance was validated by a comparison to another geodetic approach based on the subtraction of two DEMs for the years 2000 and 2009. We conclude that ICESat data is a valid source of information on surface elevation changes and on mass balance of mountain glaciers.

Download Full-text

Multi-decadal ice-velocity and elevation changes of a monsoonal maritime glacier: Hailuogou glacier, China

Journal of Glaciology ◽

10.3189/002214310791190884 ◽

2010 ◽

Vol 56 (195) ◽

pp. 65-74 ◽

Cited By ~ 42

Author(s):

Yong Zhang ◽

Koji Fujita ◽

Shiyin Liu ◽

Qiao Liu ◽

Xin Wang

Keyword(s):

Thermal Emission ◽

Surface Elevation ◽

Aerial Photographs ◽

Differential Gps ◽

Glacier Surface ◽

Ablation Area ◽

Glacier Terminus ◽

Digital Elevation ◽

Elevation Changes ◽

Ice Velocity

AbstractDigital elevation models (DEMs) of the ablation area of Hailuogou glacier, China, produced from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data obtained in 2009, differential GPS (DGPS) data surveyed in 2008 and aerial photographs acquired in 1966 and 1989 are differenced to estimate long- and short-term glacier surface elevation change (dh/dt). The mean dh/dt of the ablation area over 43 years (1966–2009) is −1.1 ± 0.4 m a−1. Since 1989 the thinning has accelerated significantly. Ice velocities measured by DGPS at 28 fixed stakes implanted in the ablation area increase with distance from the glacier terminus, ranging from 41.0 m a−1 approaching the glacier terminus to a maximum of 205.0 m a−1 at the base of an icefall. Our results reveal that the overall average ice velocity in the ablation area has undergone significant temporal variability over the past several decades. Changes in glacier surface elevation in the ablation area result from the combined effects of climate change and glacier dynamics, which are driven by different factors for different regions and periods.

Download Full-text

Spatio-Temporal Changes of Mass Balance in the Ablation Area of the Muz Taw Glacier, Sawir Mountains, from Multi-Temporal Terrestrial Geodetic Surveys

Remote Sensing ◽

10.3390/rs13081465 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1465

Author(s):

Chunhai Xu ◽

Zhongqin Li ◽

Feiteng Wang ◽

Jianxin Mu

Keyword(s):

Mass Balance ◽

Glacier Surface ◽

Surface Evolution ◽

Ablation Area ◽

Glacier Terminus ◽

Freshwater Resource ◽

Multi Temporal ◽

Elevation Changes ◽

Negative Surface ◽

Spatio Temporal

The glaciers in the Sawir Mountains are an important freshwater resource, and glaciers have been experiencing a continuing retreat over the past few decades. However, studies on detailed glacier mass changes are currently sparse. Here, we present the high-precision evolution of annual surface elevation and geodetic mass changes in the ablation area of the Muz Taw Glacier (Sawir Mountains, China) over the latest three consecutive mass-balance years (2017–2020) based on multi-temporal terrestrial geodetic surveys. Our results revealed clearly surface lowering and negative geodetic mass changes, and the spatial changing patterns were generally similar for the three periods with the most negative surface lowering (approximately −5.0 to −4.0 m a−1) around the glacier terminus. The gradient of altitudinal elevation changes was commonly steep at the low elevations and gentle in the upper-elevation parts, and reduced surface lowering was observed at the glacier terminus. Resulting emergence velocities ranged from 0.11 to 0.86 m a−1 with pronounced spatial variability, which was mainly controlled by surface slope, ice thickness, and the movement of tributary glaciers. Meanwhile, emergence velocities slightly compensated the surface ablation at the ablation area with a proportion of 14.9%, and dynamic thickening had small contributions to glacier surface evolution. Limited annual precipitation and glacier accumulation may result in these weak contributions. Higher-resolution surveys at the seasonal and monthly scales are required to get insight into the mass balance processes and their mechanism.

Download Full-text

A restitution method to reconstruct the 2001–13 surface evolution of Hurd Glacier, Livingston Island, Antarctica, using surface mass balance data

Journal of Glaciology ◽

10.1017/jog.2021.104 ◽

2021 ◽

pp. 1-14

Author(s):

Darlington Mensah ◽

Javier J. Lapazaran ◽

Jaime Otero ◽

Cayetana Recio-Blitz

Keyword(s):

Mass Balance ◽

Surface Elevation ◽

Surface Mass Balance ◽

Elevation Change ◽

Time Step ◽

Glacier Surface ◽

Surface Evolution ◽

Surface Mass ◽

Elevation Data ◽

Elevation Changes

Abstract The surface restitution method we present reconstructs the evolution of a glacier surface between two time-separated surface topographies using seasonal surface mass balance (SMB) data. A conservative and systematic error analysis is included, based on the availability of surface elevation measurements within the period. The method is applied from 2001 to 2013 at Hurd Glacier (a 4 km2 glacier), where we have sufficient SMB and elevation data. We estimate surface elevation changes in two steps: (1) elevation change due to SMB and (2) elevation change due to glacier dynamics. Four different models of the method are compared depending on whether or not accumulation is memorised at each time step and whether they employ balance profiles or SMB maps. Models are validated by comparing a set of surface measurements retrieved in 2007 with the corresponding restituted elevations. Although surface elevation change between 2001 and 2007 was larger than 10 m, more than 80% of the points restituted by the four models showed errors below ±1 m compared to only 33% when predicted by a linear interpolator. As error estimates between models differ by 0.10 m, we recommend the simplest model, which does not memorise accumulation and interpolates SMB by elevation profiles.

Download Full-text

Surface elevation changes during 2007–13 on Bowdoin and Tugto Glaciers, northwestern Greenland

Journal of Glaciology ◽

10.1017/jog.2016.106 ◽

2016 ◽

Vol 62 (236) ◽

pp. 1083-1092 ◽

Cited By ~ 14

Author(s):

SHUN TSUTAKI ◽

SHIN SUGIYAMA ◽

DAIKI SAKAKIBARA ◽

TAKANOBU SAWAGAKI

Keyword(s):

Mass Balance ◽

Satellite Observations ◽

Surface Elevation ◽

Surface Mass Balance ◽

Elevation Change ◽

Predominant Role ◽

Ice Dynamics ◽

Surface Mass ◽

Elevation Changes ◽

Negative Surface

ABSTRACTTo quantify recent thinning of marine-terminating outlet glaciers in northwestern Greenland, we carried out field and satellite observations near the terminus of Bowdoin Glacier. These data were used to compute the change in surface elevation from 2007 to 2013 and this rate of thinning was then compared with that of the adjacent land-terminating Tugto Glacier. Comparing DEMs of 2007 and 2010 shows that Bowdoin Glacier is thinning more rapidly (4.1 ± 0.3 m a−1) than Tugto Glacier (2.8 ± 0.3 m a−1). The observed negative surface mass-balance accounts for <40% of the elevation change of Bowdoin Glacier, meaning that the thinning of Bowdoin Glacier cannot be attributable to surface melting alone. The ice speed of Bowdoin Glacier increases down-glacier, reaching 457 m a−1 near the calving front. This flow regime causes longitudinal stretching and vertical compression at a rate of −0.04 a−1. It is likely that this dynamically-controlled thinning has been enhanced by the acceleration of the glacier since 2000. Our measurements indicate that ice dynamics indeed play a predominant role in the rapid thinning of Bowdoin Glacier.

Download Full-text

An optimized method to calculate the geodetic mass balance of mountain glaciers

Journal of Glaciology ◽

10.1017/jog.2018.79 ◽

2018 ◽

Vol 64 (248) ◽

pp. 917-931 ◽

Cited By ~ 1

Author(s):

RUBÉN BASANTES-SERRANO ◽

ANTOINE RABATEL ◽

CHRISTIAN VINCENT ◽

PASCAL SIRGUEY

Keyword(s):

Spatial Variability ◽

Mass Balance ◽

Mean Difference ◽

Full Density ◽

Elevation Change ◽

Low Contrast ◽

Mountain Glaciers ◽

Elevation Changes ◽

Geodetic Mass Balance ◽

Similar Accuracy

ABSTRACTUnderstanding the effects of climate on glaciers requires precise estimates of ice volume change over several decades. This is achieved by the geodetic mass balance computed by two means: (1) the digital elevation model (DEM) comparison (SeqDEM) allows measurements over the entire glacier, however the low contrast over glacierized areas is an issue for the DEM generation through the photogrammetric techniques and (2) the profiling method (SePM) is a faster alternative but fails to capture the spatial variability of elevation changes. We present a new framework (SSD) that relies upon the spatial variability of the elevation change to densify a sampling network to optimize the surface-elevation change quantification. Our method was tested in two small glaciers over different periods. We conclude that the SePM overestimates the elevation change by ~20% with a mean difference of ~1.00 m (root mean square error (RMSE) = ~3.00 m) compared with results from the SeqDEM method. A variogram analysis of the elevation changes showed a mean difference of <0.10 m (RMSE = ~2.40 m) with SSD approach. A final assessment on the largest glacier in the French Alps confirms the high potential of our method to compute the geodetic mass balance, without going through the generation of a full-density DEM, but with a similar accuracy than the SeqDEM approach.

Download Full-text

Geodetic Mass Balance of Haxilegen Glacier No. 51, Eastern Tien Shan, from 1964 to 2018

Remote Sensing ◽

10.3390/rs14020272 ◽

2022 ◽

Vol 14 (2) ◽

pp. 272

Author(s):

Chunhai Xu ◽

Zhongqin Li ◽

Feiteng Wang ◽

Jianxin Mu ◽

Xin Zhang

Keyword(s):

Mass Loss ◽

Mass Balance ◽

Laser Scanning ◽

Mean Value ◽

Tien Shan ◽

Glacier Mass Balance ◽

Topographic Map ◽

Glacier Surface ◽

Elevation Changes ◽

Geodetic Mass Balance

The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive glaciological measurements were implemented from 1999 to 2011 and re-established in 2017. Mass balance of Haxilegen Glacier No. 51 (1999–2015) has recently been reported, but the mass balance record has not extended to the period before 1999. Here, we used a 1:50,000-scale topographic map and long-range terrestrial laser scanning (TLS) data to calculate the area, volume, and mass changes for Haxilegen Glacier No. 51 from 1964 to 2018. Haxilegen Glacier No. 51 lost 0.34 km2 (at a rate of 0.006 km2 a−1 or 0.42% a−1) of its area during the period 1964–2018. The glacier experienced clearly negative surface elevation changes and geodetic mass balance. Thinning occurred almost across the entire glacier surface, with a mean value of −0.43 ± 0.12 m a−1. The calculated average geodetic mass balance was −0.36 ± 0.12 m w.e. a−1. Without considering the error bounds of mass balance estimates, glacier mass loss over the past 50 years was in line with the observed and modeled mass balance (−0.37 ± 0.22 m w.e. a−1) that was published for short time intervals since 1999 but was slightly less negative than glacier mass loss in the entire eastern Tien Shan. Our results indicate that Riegl VZ®-6000 TLS can be widely used for mass balance measurements of unmonitored individual glaciers.

Download Full-text

Unravelling the evolution of Zmuttgletscher and its debris cover since the end of the Little Ice Age

The Cryosphere ◽

10.5194/tc-13-1889-2019 ◽

2019 ◽

Vol 13 (7) ◽

pp. 1889-1909 ◽

Cited By ~ 8

Author(s):

Nico Mölg ◽

Tobias Bolch ◽

Andrea Walter ◽

Andreas Vieli

Keyword(s):

Mass Balance ◽

Ice Age ◽

Aerial Photographs ◽

Dynamic Interactions ◽

Glacier Surface ◽

Ablation Area ◽

Debris Cover ◽

Historic Maps ◽

Length And Area ◽

Flow Velocities

Abstract. Debris-covered glaciers generally exhibit large, gently sloping, slow-flowing tongues. At present, many of these glaciers show high thinning rates despite thick debris cover. Due to the lack of observations, most existing studies have neglected the dynamic interactions between debris cover and glacier evolution over longer time periods. The main aim of this study is to reveal such interactions by reconstructing changes of debris cover, glacier geometry, flow velocities, and surface features of Zmuttgletscher (Switzerland), based on historic maps, satellite images, aerial photographs, and field observations. We show that debris cover extent has increased from ∼13 % to ∼32 % of the total glacier surface since 1859 and that in 2017 the debris is sufficiently thick to reduce ablation compared to bare ice over much of the ablation area. Despite the debris cover, the glacier-wide mass balance of Zmuttgletscher is comparable to that of debris-free glaciers located in similar settings, whereas changes in length and area have been small and delayed by comparison. Increased ice mass input in the 1970s and 1980s resulted in a temporary velocity increase, which led to a local decrease in debris cover extent, a lowering of the upper boundary of the ice-cliff zone, and a strong reduction in ice-cliff area, indicating a dynamic link between flow velocities, debris cover, and surface morphology. Since 2005, the lowermost 1.5 km of the glacier has been quasi-stagnant, despite a slight increase in the surface slope of the glacier tongue. We conclude that the long-term glacier-wide mass balance is mainly governed by climate. The debris cover governs the spatial pattern of elevation change without changing its glacier-wide magnitude, which we explain by the extended ablation area and the enhanced thinning in regions with thin debris further up-glacier and in areas with abundant meltwater channels and ice cliffs. At the same time rising temperatures lead to increasing debris cover and decreasing ice flux, thereby attenuating length and area losses.

Download Full-text

Glacier surface elevation changes in Rongbuk Catchment of the Central Himalayas in the last four decades

10.5194/egusphere-egu2020-9125 ◽

2020 ◽

Author(s):

Qinghua Ye ◽

Wei Nie ◽

Yimin Chen ◽

Gang Li ◽

lide Tian ◽

...

Keyword(s):

Climate Modeling ◽

Melting Rate ◽

Surface Elevation ◽

High Mountain ◽

Glacier Surface ◽

Important Indicator ◽

Central Himalayas ◽

Glacier Melting ◽

Elevation Changes ◽

Thinning Rate

Glaciers in the central Himalayas are important water resources for the downstream habitants, and accelerating melting of the high mountain glaciers speed up with continuous warming. We summerized the geodetic glacier surface elevation changes (Dh) by 6 data sets at different time periods during 1974-2016 in RongbukCatchment(RC) on the northern slope of Mt. Qomolangma (Mt. Everest) in the Central Himalayas. The result showed that glacier Dh varied with altitude and time, from -0.29 &#177; 0.03m a-1 in 1974-2000, to -0.47 &#177;0.24 m a-1 in 1974-2006,and -0.48 &#177;0.16 m a-1 in 1974-2012. Dh increased to -0.60 &#177; 0.20 m a-1 in 2000-2012, then decreased to-0.46 &#177; 0.24 m a-1 in 2000-2014, and by -0.49 &#177; 0.08 m a-1 in 2000-2016, showing a diverse rate being up - down- a little up. However, it generally presented a similar glacier thinning rate by -0.46~-0.49 m a-1 in the last four decades since 1970s in RC according to Dh1974-2006, Dh1974-2012, Dh2000-2014, and Dh2000-2016. Local meteorological observations revealed that, to a first order, the glacier thinning rate was kept the same pace with the number of annual melting days (MD). In spite of the obviously arising summer air temperature (TS) in 2000-2014, a slowdown glacier melting rate by -391 mm w.e.a-1 occurred in 2000-2014 because of less melting days with more precipitation and less annual mean temperature(Tm). It shows that MD is another important indicator and controlling factor to evaluate or to estimate glacier melting trend, especially in hydrological or climate modeling.

Download Full-text

Surface elevation and mass changes of all Swiss glaciers 1980–2010

The Cryosphere ◽

10.5194/tc-9-525-2015 ◽

2015 ◽

Vol 9 (2) ◽

pp. 525-540 ◽

Cited By ~ 97

Author(s):

M. Fischer ◽

M. Huss ◽

M. Hoelzle

Keyword(s):

Mass Balance ◽

Accuracy Assessment ◽

Swiss Alps ◽

Surface Elevation ◽

European Alps ◽

Volume Changes ◽

Glacier Inventory ◽

Digital Elevation ◽

Source Data ◽

Geodetic Mass Balance

Abstract. Since the mid-1980s, glaciers in the European Alps have shown widespread and accelerating mass losses. This article presents glacier-specific changes in surface elevation, volume and mass balance for all glaciers in the Swiss Alps from 1980 to 2010. Together with glacier outlines from the 1973 inventory, the DHM25 Level 1 digital elevation models (DEMs) for which the source data over glacierized areas were acquired from 1961 to 1991 are compared to the swissALTI3D DEMs from 2008 to 2011 combined with the new Swiss Glacier Inventory SGI2010. Due to the significant differences in acquisition dates of the source data used, mass changes are temporally homogenized to directly compare individual glaciers or glacierized catchments. Along with an in-depth accuracy assessment, results are validated against volume changes from independent photogrammetrically derived DEMs of single glaciers. Observed volume changes are largest between 2700 and 2800 m a.s.l. and remarkable even above 3500 m a.s.l. The mean geodetic mass balance is −0.62 ± 0.07 m w.e. yr−1 for the entire Swiss Alps over the reference period 1980–2010. For the main hydrological catchments, it ranges from −0.52 to −1.07 m w.e. yr−1. The overall volume loss calculated from the DEM differencing is −22.51 ± 1.76 km3.

Download Full-text

Fifty Years of Tidewater Glacier Surface Elevation and Retreat Dynamics along the South-East Coast of Spitsbergen (Svalbard Archipelago)

Remote Sensing ◽

10.3390/rs14020354 ◽

2022 ◽

Vol 14 (2) ◽

pp. 354

Author(s):

Jan Kavan ◽

Guy D. Tallentire ◽

Mihail Demidionov ◽

Justyna Dudek ◽

Mateusz C. Strzelecki

Keyword(s):

East Coast ◽

Aerial Images ◽

Surface Elevation ◽

Glacier Surface ◽

Svalbard Archipelago ◽

Tidewater Glaciers ◽

Air Temperatures ◽

Frontal Zones ◽

Elevation Changes ◽

Norwegian Polar Institute

Tidewater glaciers on the east coast of Svalbard were examined for surface elevation changes and retreat rate. An archival digital elevation model (DEM) from 1970 (generated from aerial images by the Norwegian Polar Institute) in combination with recent ArcticDEM were used to compare the surface elevation changes of eleven glaciers. This approach was complemented by a retreat rate estimation based on the analysis of Landsat and Sentinel-2 images. In total, four of the 11 tidewater glaciers became land-based due to the retreat of their termini. The remaining tidewater glaciers retreated at an average annual retreat rate of 48 m year−1, and with range between 10–150 m year−1. All the glaciers studied experienced thinning in their frontal zones with maximum surface elevation loss exceeding 100 m in the ablation areas of three glaciers. In contrast to the massive retreat and thinning of the frontal zones, a minor increase in ice thickness was recorded in some accumulation areas of the glaciers, exceeding 10 m on three glaciers. The change in glacier geometry suggests an important shift in glacier dynamics over the last 50 years, which very likely reflects the overall trend of increasing air temperatures. Such changes in glacier geometry are common at surging glaciers in their quiescent phase. Surging was detected on two glaciers studied, and was documented by the glacier front readvance and massive surface thinning in high elevated areas.

Download Full-text