Minor Imbalance of the Lowermost Italian Glacier from 2006 to 2019

The response of very small glaciers to climate changes is highly scattered and little known in comparison with larger ice bodies. In particular, small avalanche-fed and debris-covered glaciers lack mass balance series of sufficient length. In this paper we present 13 years of high-resolution observations over the Occidentale del Montasio Glacier, collected using Airborne Laser Scanning, Terrestrial Laser Scanning, and Structure from Motion Multi-View Stereo techniques for monitoring its geodetic mass balance and surface dynamics. The results have been analyzed jointly with meteorological variables, and compared to a sample of “reference” glaciers for the European Alps. From 2006 to 2019 the mass balance showed high interannual variability and an average rate much closer to zero than the average of the Alpine reference glaciers (−0.09 vs. −1.42 m water equivalent per year, respectively). This behavior can be explained by the high correlation between annual balance and solid precipitation, which displayed recent peaks. The air temperature is not significantly correlated with the mass balance, which is main controlled by avalanche activity, shadowing and debris cover. However, its rapid increase is progressively reducing the fraction of solid precipitation, and increasing the length of the ablation season.

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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.

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Investigations on intra-annual elevation changes using multi-temporal airborne laser scanning data: case study Engabreen, Norway

Annals of Glaciology ◽

10.3189/172756405781812592 ◽

2005 ◽

Vol 42 ◽

pp. 195-201 ◽

Cited By ~ 34

Author(s):

Thomas Geist ◽

Hallgeir Elvehøy ◽

Miriam Jackson ◽

Johann Stötter

Keyword(s):

Mass Balance ◽

Laser Scanning ◽

Laser Scanner ◽

Remote Sensing Data ◽

Control Area ◽

Airborne Laser Scanning ◽

Time Interval ◽

Scanner Data ◽

Glacier Surface ◽

Airborne Laser

AbstractKey issues of glacier monitoring are changes in glacier geometry and glacier mass. As accurate direct measurements are costly and time-consuming, the use of various remote-sensing data for glacier monitoring is explored. One technology used and described here is airborne laser scanning. The method enables the derivation of high-quality digital elevation models (DEMs) with a vertical and horizontal accuracy in the sub-metre range. Between September 2001 and August 2002, three laser scanner data acquisition flights were carried out, covering the whole area of Engabreen, Norway, and corresponding well to the measurement dates for the mass-balance year 2001/02. The data quality of the DEMs is assessed (e.g. by comparing the values with a control area which has been surveyed independently or GPS ground profiles measured during the flights). For the whole glacier, surface elevation change and consequently volume change is calculated, quantified and compared with traditional mass-balance data for the same time interval. For the winter term, emergence/submergence velocity is determined from laser scanner data and snow-depth data and is compared with velocity measurements at stakes. The investigations reveal the high potential of airborne laser scanning for measuring the extent and the topography of glaciers as well as changes in geometry (Δarea, Δvolume).

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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.

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New long-term mass-balance series for the Swiss Alps

Journal of Glaciology ◽

10.3189/2015jog15j015 ◽

2015 ◽

Vol 61 (227) ◽

pp. 551-562 ◽

Cited By ~ 29

Author(s):

Matthias Huss ◽

Laurie Dhulst ◽

Andreas Bauder

Keyword(s):

Mass Balance ◽

Spatial Interpolation ◽

Swiss Alps ◽

Continuous Series ◽

European Alps ◽

Ice Volume ◽

Distributed Modelling ◽

Direct Measurements ◽

Annual Balance

AbstractIn this study we present 19 new or re-analysed series of glacier-wide seasonal mass balance for the Swiss Alps based on direct measurements. The records partly start around 1920 and continue until today. Previously unpublished and unevaluated observations of point winter and annual balance are compiled from various sources and archives. These highly valuable datasets have not yet been consistently evaluated and were thus unavailable to the scientific community. Using distributed modelling for spatial interpolation and extrapolation and homogenization of the point measurements, we infer continuous series of area-averaged mass balance. The results are validated against independent decadal ice volume changes from photogrammetric surveys. Six of the new seasonal series cover 60 years and more and add a substantial amount of information on the variations of regional glacier mass change. This will strengthen the worldwide collection of glacier monitoring data, especially for the data-sparse period before the 1980s. We compare our results to existing long-term series and present an updated assessment of mass-balance variability and glacier sensitivity throughout the European Alps.

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Observations of enhanced thinning in the upper reaches of Svalbard glaciers

The Cryosphere ◽

10.5194/tc-6-1369-2012 ◽

2012 ◽

Vol 6 (6) ◽

pp. 1369-1381 ◽

Cited By ~ 42

Author(s):

T. D. James ◽

T. Murray ◽

N. E. Barrand ◽

H. J. Sykes ◽

A. J. Fox ◽

...

Keyword(s):

Mass Balance ◽

Average Rate ◽

Winter Precipitation ◽

Svalbard Archipelago ◽

Ice Surface ◽

Considerable Research ◽

Elevation Data ◽

Elevation Changes ◽

The Subject ◽

Geodetic Mass Balance

Abstract. Changes in the volume and extent of land ice of the Svalbard archipelago have been the subject of considerable research since their sensitivity to changes in climate was first noted. However, the measurement of these changes is often necessarily based on point or profile measurements which may not be representative if extrapolated to a whole catchment or region. Combining high-resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's surface without the need for extrapolation. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard archipelago spanning 1961 to 2005. We find high variability in thinning rates between sites with prevalent elevation changes at all sites averaging −0.59 ± 0.04 m a−1 between 1961–2005. Prior to 1990, ice surface elevation was changing at an average rate of −0.52 ± 0.09 m a−1 which decreased to −0.76 ± 0.10 m a−1 after 1990. Setting the elevation changes against the glaciers' altitude distribution reveals that significant increases in thinning rates are occurring most notably in the glaciers' upper reaches. We find that these changes are coincident with a decrease in winter precipitation at the Longyearbyen meteorological station and could reflect a decrease in albedo or dynamic response to lower accumulation. Further work is required to understand fully the causes of this increase in thinning rates in the glaciers' upper reaches. If on-going and occurring elsewhere in the archipelago, these changes will have a significant effect on the region's future mass balance. Our results highlight the importance of understanding the climatological context of geodetic mass balance measurements and demonstrate the difficulty of using index glaciers to represent regional changes in areas of strong climatological gradients.

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Geodetic reanalysis of annual glaciological mass balances (2001–2011) of Hintereisferner, Austria

The Cryosphere ◽

10.5194/tc-12-833-2018 ◽

2018 ◽

Vol 12 (3) ◽

pp. 833-849 ◽

Cited By ~ 13

Author(s):

Christoph Klug ◽

Erik Bollmann ◽

Stephan Peter Galos ◽

Lindsey Nicholson ◽

Rainer Prinz ◽

...

Keyword(s):

High Resolution ◽

Mass Balance ◽

Laser Scanning ◽

Meteorological Conditions ◽

Mass Balances ◽

Statistical Comparison ◽

Airborne Laser ◽

Significant Difference ◽

Cumulative Mass ◽

Grid Based

Abstract. This study presents a reanalysis of the glaciologically obtained annual glacier mass balances at Hintereisferner, Ötztal Alps, Austria, for the period 2001–2011. The reanalysis is accomplished through a comparison with geodetically derived mass changes, using annual high-resolution airborne laser scanning (ALS). The grid-based adjustments for the method-inherent differences are discussed along with associated uncertainties and discrepancies of the two methods of mass balance measurements. A statistical comparison of the two datasets shows no significant difference for seven annual, as well as the cumulative, mass changes over the 10-year record. Yet, the statistical view hides significant differences in the mass balance years 2002/03 (glaciological minus geodetic records  = +0.92 m w.e.), 2005/06 (+0.60 m w.e.), and 2006/07 (−0.45 m w.e.). We conclude that exceptional meteorological conditions can render the usual glaciological observational network inadequate. Furthermore, we consider that ALS data reliably reproduce the annual mass balance and can be seen as validation or calibration tools for the glaciological method.

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Multi-year Evaluation of Airborne Geodetic Surveys to Estimate Seasonal Mass Balance, Columbia and Rocky Mountains, Canada

10.5194/tc-2019-30 ◽

2019 ◽

Author(s):

Ben M. Pelto ◽

Brian Menounos ◽

Shawn J. Marshall

Keyword(s):

Mass Balance ◽

Rocky Mountains ◽

Laser Scanning ◽

Late Summer ◽

Mass Change ◽

Glacier Mass Balance ◽

Digital Elevation ◽

Surface Classification ◽

The Difference ◽

Annual Balance

Abstract. Seasonal measurements of glacier mass balance provide insight into the relation between climate forcing and glacier change. To evaluate the feasibility of using remotely-sensed methods to assess seasonal balance we completed tandem airborne laser scanning surveys (ALS) and field-based glaciological measurements over a four-year period for six alpine glaciers that lie in Columbia and Rocky Mountains, near the headwaters of the Columbia River, British Columbia, Canada. We calculated annual geodetic balance using co-registered late-summer digital elevation models (DEMs), and distributed estimates of density based on surface classification of ice, snow and firn surfaces. Winter balance was derived using co-registered late-summer and spring DEMs, and density measurements from regional snow course observations and our glaciological measurements. Geodetic summer balance was calculated as the difference between winter and annual balance. Winter mass balance from our glaciological observations averaged 1.95 ± 0.09 m w.e., 4 % greater than those derived from geodetic surveys. Average glaciological summer and annual balance were also 4 % greater than our geodetic estimates. We find that distributing snow, firn and ice density based on surface classification has a greater influence on geodetic annual mass change than the density values themselves. Our results demonstrate that accurate assessments of seasonal mass change can be produced using airborne ALS over a series of glaciers spanning several mountain ranges. Such agreement over multiple seasons, years, and glaciers demonstrates the ability of high-resolution geodetic methods to increase the number of glaciers where seasonal mass balance can be reliably measured.

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Long-term mass-balance monitoring and evolution of ice in caves through structure from motion–multi-view stereo and ground-penetrating radar techniques

Progress in Physical Geography Earth and Environment ◽

10.1177/03091333211065123 ◽

2022 ◽

pp. 030913332110651

Author(s):

Andrea Securo ◽

Emanuele Forte ◽

Davide Martinucci ◽

Simone Pillon ◽

Renato R Colucci

Keyword(s):

Mass Balance ◽

Ground Penetrating Radar ◽

Laser Scanning ◽

Low Cost ◽

Extreme Environments ◽

Point Clouds ◽

Acquisition Time ◽

European Alps ◽

Ground Penetrating

This study investigates the application of a terrestrial structure from motionmulti-view stereo (SfM-MVS) approach combined with ground-penetrating radar (GPR) surveys for monitoring the surface topographic change of two permanent ice deposits in caves located in the Julian Alps (south-eastern European Alps). This method allows accurate calculation of both seasonal and annual mass balance, estimating the amount of ice inside caves. The ground-based SfM approach represents a low-cost workflow with very limited logistical problems of transportation and human resources and a fast acquisition time, all key factors in such extreme environments. Under optimal conditions, SfM-MVS allows sub-centimetric resolution results, comparable to more expensive and logistically demanding surveys such as terrestrial laser scanning (TLS). Fourteen SfM acquisitions were made between the 2017–2020 ablation seasons (i.e. July–October) while 2 GPR surveys were acquired in 2012. The obtained dense point clouds and digital terrain models (DTMs) made possible a reliable calculation of topographic changes and mass balance rates during the analysed period. The integration of SfM-MVS products with GPR surveys provided comprehensive imaging of the ice thickness and the total ice volume present in each of the caves, proving to be a reliable, low cost and multipurpose methodology ideal for long-term monitoring.

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Comparison of direct and geodetic mass balances on a multi-annual time scale

The Cryosphere ◽

10.5194/tc-5-107-2011 ◽

2011 ◽

Vol 5 (1) ◽

pp. 107-124 ◽

Cited By ~ 65

Author(s):

A. Fischer

Keyword(s):

Mass Balance ◽

Laser Scanning ◽

Climate Forcing ◽

Mass Balances ◽

Scanning Lidar ◽

Cumulative Difference ◽

The Mean ◽

The Difference ◽

Geodetic Mass Balance ◽

Seasonal Snow Cover

Abstract. The geodetic mass balances of six Austrian glaciers over 19 periods between 1953 and 2006 are compared to the direct mass balances over the same periods. For two glaciers, Hintereisferner and Kesselwandferner, case studies showing possible reasons for discrepancies between the geodetic and the direct mass balance are presented. The mean annual geodetic mass balance for all periods is −0.5 m w.e. a−1, the mean annual direct mass balance −0.4 m w.e. a−1. The mean cumulative difference is −0.6 m w.e., the minimum −7.3 m w.e., and the maximum 5.6 m w.e. The accuracy of geodetic mass balance may depend on the accuracy of the DEMs, which ranges from 2 m w.e. for photogrammetric data to 0.02 m w.e. for airborne laser scanning (LiDAR) data. Basal melt, seasonal snow cover, and density changes of the surface layer also contribute up to 0.7 m w.e. to the difference between the two methods over the investigated period of 10 yr. On Hintereisferner, the fraction of area covered by snow or firn has been changing within 1953–2006. The accumulation area is not identical with the firn area, and both are not coincident with areas of volume gain. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Trends in the difference between the direct and the geodetic data vary from glacier to glacier and can differ systematically for specific glaciers under specific types of climate forcing. Ultimately, geodetic and direct mass balance data are complementary, and great care must be taken when attempting to combine them.

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Recent Increases in Winter Snowfall Provide Resilience to Very Small Glaciers in the Julian Alps, Europe

Atmosphere ◽

10.3390/atmos12020263 ◽

2021 ◽

Vol 12 (2) ◽

pp. 263

Author(s):

Renato R. Colucci ◽

Manja Žebre ◽

Csaba Zsolt Torma ◽

Neil F. Glasser ◽

Eleonora Maset ◽

...

Keyword(s):

Mass Balance ◽

Atlantic Multidecadal Oscillation ◽

Snow Accumulation ◽

Annual Precipitation ◽

Mean Annual Precipitation ◽

European Alps ◽

Positive Feedbacks ◽

Winter Snow ◽

Geodetic Mass Balance ◽

The Impact

Very small glaciers (<0.5 km2) account for more than 80% of the total number of glaciers and more than 15% of the total glacier area in the European Alps. This study seeks to better understand the impact of extreme snowfall events on the resilience of very small glaciers and ice patches in the southeastern European Alps, an area with the highest mean annual precipitation in the entire Alpine chain. Mean annual precipitation here is up to 3300 mm water equivalent, and the winter snow accumulation is approximately 6.80 m at 1800 m asl averaged over the period 1979–2018. As a consequence, very small glaciers and ice/firn patches are still present in this area at rather low altitudes (1830–2340 m). We performed repeated geodetic mass balance measurements on 14 ice bodies during the period 2006–2018 and the results show an increase greater than 10% increase in ice volume over this period. This is in accordance with several extreme winter snow accumulations in the 2000s, promoting a positive mass balance in the following years. The long-term evolution of these very small glaciers and ice bodies matches well with changes in mean temperature of the ablation season linked to variability of Atlantic Multidecadal Oscillation. Nevertheless, the recent behaviour of such residual ice masses in this area where orographic precipitation represents an important component of weather amplification is somehow different to most of the Alps. We analysed synoptic meteorological conditions leading to the exceptional snowy winters in the 2000s, which appear to be related to the influence and modification of atmospheric planetary waves and Arctic Amplification, with further positive feedbacks due to change in local sea surface temperature and its interactions with low level flows and the orography. Although further summer warming is expected in the next decades, we conclude that modification of storm tracks and more frequent occurrence of extreme snowfall events during winter are crucial in ensuring the resilience of small glacial remnants in maritime alpine sectors.

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