Determination of length, area, and volume changes at Storglaciären, Sweden, from multi-temporal aerial images (1959–1999)

Abstract. Storglaciären, located in the Kebnekaise massif in northern Sweden, has a long history of glaciological research. Early photo documentations date back to the late 19th century. Measurements of front position variations and distributed mass balance have been carried out since 1910 and 1945/46, respectively. In addition to these in-situ measurements, aerial photographs have been taken at decadal intervals since the beginning of the mass balance monitoring program and were used to produce glaciological maps. Inaccuracies in the maps were a challenge to early attempts to derive glacier volume changes and resulted in major differences when compared to the direct glaciological mass balances. In this study, we reanalyzed dia-positives of the original aerial photographs of 1959, -69, -80, -90 and -99 based on consistent photogrammetric processing. From the resulting digital elevation models and orthophotos, changes in length, area, and volume of Storglaciären are computed between the survey years, including an assessment of related errors. Between 1959 and 1999, Storglaciären lost an ice volume of 19×106 m3, which corresponds to a cumulative ice thickness loss of 5.69 m and a mean annual loss of 0.14 m. This ice loss resulted largely from a strong volume loss during the period 1959–1980 and was partly compensated during the period 1980–1999. As a consequence, the glacier shows a strong retreat in the 1960s, a slowing in the 1970s, and pseudo-stationary conditions in the 1980s and 1990s.

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Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959–99) – Part 1: Determination of length, area, and volume changes

The Cryosphere ◽

10.5194/tc-4-333-2010 ◽

2010 ◽

Vol 4 (3) ◽

pp. 333-343 ◽

Cited By ~ 73

Author(s):

T. Koblet ◽

I. Gärtner-Roer ◽

M. Zemp ◽

P. Jansson ◽

P. Thee ◽

...

Keyword(s):

Mass Balance ◽

Monitoring Program ◽

Aerial Images ◽

Aerial Photographs ◽

Volume Changes ◽

Front Position ◽

Digital Elevation ◽

Multi Temporal ◽

The 1960S ◽

Area And Volume

Abstract. Storglaciären, located in the Kebnekaise massif in northern Sweden, has a long history of glaciological research. Early photo documentations date back to the late 19th century. Measurements of front position variations and distributed mass balance have been carried out since 1910 and 1945/46, respectively. In addition to these in-situ measurements, aerial photographs have been taken at decadal intervals since the beginning of the mass balance monitoring program and were used to produce topographic glacier maps. Inaccuracies in the maps were a challenge to early attempts to derive glacier volume changes and resulted in major differences when compared to the direct glaciological mass balances. In this study, we reanalyzed dia-positives of the original aerial photographs of 1959, -69, -80, -90 and -99 based on consistent photogrammetric processing. From the resulting digital elevation models and orthophotos, changes in length, area, and volume of Storglaciären were computed between the survey years, including an assessment of related errors. Between 1959 and 1999, Storglaciären lost an ice volume of 19×106 m3, which corresponds to a cumulative ice thickness loss of 5.69 m and a mean annual loss of 0.14 m. This ice loss resulted largely from a strong volume loss during the period 1959–80 and was partly compensated during the period 1980–99. As a consequence, the glacier shows a strong retreat in the 1960s, a slowing in the 1970s, and pseudo-stationary conditions in the 1980s and 1990s.

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Multi-temporal mass balance changes of the Northern Patagonian Icefield from 1975 to 2016

10.5194/egusphere-egu2020-18706 ◽

2020 ◽

Author(s):

Etienne Berthier ◽

Ines Dussaillant ◽

Fanny Brun ◽

Vincent Favier

Keyword(s):

Mass Loss ◽

Mass Balance ◽

Shuttle Radar Topography Mission ◽

Ice Age ◽

Aerial Photographs ◽

Digital Elevation ◽

Multi Temporal ◽

The Mean ◽

Military Institute ◽

Year 2000

The northern Patagonian Icefield (NPI) is the second largest ice mass in Patagonia (3740 km&#178;). Estimation of recent volume changes confirm an acceleration of ice loss in the last decades compared to the mean mass loss since the Little Ice Age. However, Icefield-wide responses at shorter time scales (5-25 yrs) are still poorly documented and not well understood.We compare five digital elevation models (DEM) acquired between 1975 and 2016 over the NPI: SPOT6 and SPOT7 DEMs for year 2016, SPOT5-HRS DEMs for 2012 and 2005, the Shuttle Radar Topography Mission DEM (SRTM) for year 2000 and the earlier Chilean military institute cartography (IGM) derived from aerial photographs acquired in 1975. We derive cefield-wide mass balances during four different time periods (1975-2000, 2000-2005, 2005-2012, 2012-2016). Our results suggest an acceleration of mass loss from 1975 to 2016. Although error bars are large, we suggest a shift from moderately negative icefield-wide mass balance rates before 2000 (of the order of -0.6 m w.e. yr-1), towards larger mass losses during the first decade of the 21st century(of the order of -0.8 m w.e. yr-1) and even more negative value from 2012 to 2016 (-1.2 &#177; 0.2 m w.e. yr-1).But these results must be considered cautiously. The 1975-2000 map of elevation change shows a thickening rate of over 1 m/yr which are not supported by image analysis. We stress the need to construct a revised 1975 NPI topography in order to document the NPI mass balance observations back to 1975 with improved confidence.

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Changes in the southeast Vatnajökull ice cap, Iceland, between ~ 1890 and 2010

The Cryosphere ◽

10.5194/tc-9-565-2015 ◽

2015 ◽

Vol 9 (2) ◽

pp. 565-585 ◽

Cited By ~ 32

Author(s):

H. Hannesdóttir ◽

H. Björnsson ◽

F. Pálsson ◽

G. Aðalgeirsdóttir ◽

Sv. Guðmundsson

Keyword(s):

Mass Balance ◽

Aerial Images ◽

Ice Age ◽

Volume Loss ◽

Volume Changes ◽

Glacier Surface ◽

Early 21St Century ◽

Ice Cap ◽

Multi Temporal ◽

Geodetic Mass Balance

Abstract. Area and volume changes and the average geodetic mass balance of the non-surging outlet glaciers of the southeast Vatnajökull ice cap, Iceland, during different time periods between ~ 1890 and 2010, are derived from a multi-temporal glacier inventory. A series of digital elevation models (DEMs) (~ 1890, 1904, 1936, 1945, 1989, 2002, 2010) are compiled from glacial geomorphological features, historical photographs, maps, aerial images, DGPS measurements and a lidar survey. Given the mapped basal topography, we estimate volume changes since the end of the Little Ice Age (LIA) ~ 1890. The variable volume loss of the outlets to similar climate forcing is related to their different hypsometry, basal topography, and the presence of proglacial lakes. In the post-LIA period, the glacierized area decreased by 164 km2 (or from 1014 to 851 km2) and the glaciers had lost 10–30 % of their ~ 1890 area by 2010 (anywhere from 3 to 36 km2). The glacier surface lowered by 150–270 m near the terminus and the outlet glaciers collectively lost 60 ± 8 km3 of ice, which is equivalent to 0.15 ± 0.02 mm of sea-level rise. The volume loss of individual glaciers was in the range of 15–50%, corresponding to a geodetic mass balance between −0.70 and −0.32 m w.e. a−1. The annual rate of mass change during the post-LIA period was most negative in 2002–2010, on average −1.34 ± 0.12 m w.e. a−1, which is among the most negative mass balance values recorded worldwide in the early 21st century.

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Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959–99) – Part 2: Comparison of glaciological and volumetric mass balances

The Cryosphere ◽

10.5194/tc-4-345-2010 ◽

2010 ◽

Vol 4 (3) ◽

pp. 345-357 ◽

Cited By ~ 58

Author(s):

M. Zemp ◽

P. Jansson ◽

P. Holmlund ◽

I. Gärtner-Roer ◽

T. Koblet ◽

...

Keyword(s):

Mass Balance ◽

Uncertainty Assessment ◽

Aerial Images ◽

Aerial Photographs ◽

Data Series ◽

Mass Balances ◽

Stochastic Error ◽

Systematic Uncertainties ◽

Multi Temporal

Abstract. Seasonal glaciological mass balances have been measured on Storglaciären without interruption since 1945/46. In addition, aerial surveys have been carried out on a decadal basis since the beginning of the observation program. Early studies had used the resulting aerial photographs to produce topographic glacier maps with which the in-situ observations could be verified. However, these maps as well as the derived volume changes are subject to errors which resulted in major differences between the derived volumetric and the glaciological mass balance. As a consequence, the original photographs were re-processed using uniform photogrammetric methods, which resulted in new volumetric mass balances for 1959–69, 1969–80, 1980–90, and 1990–99. We compared these new volumetric mass balances with mass balances obtained by standard glaciological methods including an uncertainty assessment considering all related previous studies. The absolute differences between volumetric and the glaciological mass balances are 0.8 m w.e. for the period of 1959–69 and 0.3 m w.e. or less for the other survey periods. These deviations are slightly reduced when considering corrections for systematic uncertainties due to differences in survey dates, reference areas, and internal ablation, whereas internal accumulation systematically increases the mismatch. However, the mean annual differences between glaciological and volumetric mass balance are less than the uncertainty of the in-situ stake reading and stochastic error bars of both data series overlap. Hence, no adjustment of the glaciological data series to the volumetric one is required.

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The new Swiss Glacier Inventory SGI2016: a detailed cartographic representation of Swiss glacier extent and supraglacial debris-cover

10.5194/egusphere-egu21-5873 ◽

2021 ◽

Author(s):

Andreas Linsbauer ◽

Matthias Huss ◽

Elias Hodel ◽

Andreas Bauder ◽

Mauro Fischer ◽

...

Keyword(s):

Surface Area ◽

Swiss Alps ◽

Aerial Images ◽

Aerial Photographs ◽

Slope Aspect ◽

Relative Area ◽

Glacier Surface ◽

Glacier Inventory ◽

Digital Elevation ◽

Debris Cover

With increasing anthropogenic greenhouse gas emissions and corresponding global warming, glaciers in Switzerland are shrinking rapidly as in many mountain ranges on Earth. Repeated glacier inventories are a key task to monitor such glacier changes and provide detailed information on the extent of glaciation, and important parameters such as area, elevation range, slope, aspect etc. for a given point or a period in time. Here we present the new Swiss Glacier Inventory (SGI2016) that has been acquired based on high-resolution aerial imagery and digital elevation models in cooperation with the Federal Office of Topography (swisstopo) and Glacier Monitoring in Switzerland (GLAMOS), bringing together topological and glaciological knowhow. We define the process, workflow and required glaciological adaptations to compile a highly accurate glacier inventory based on the digital Swiss topographic landscape model (swissTLM3D).The SGI2016 provides glacier outlines (areas), supraglacial debris cover, ice divides and location points of all glaciers in Switzerland referring to the years 2013-2018, whereas most of the glacier outlines have been mapped based on aerial images acquired between 2015-2017 (75% in number and 87% in area), with the centre year 2016. The SGI2016 maps 1400 individual glacier entities with a total glacier surface area of 961 km2 (whereof 11% / 104 km2 are debris-covered) and constitutes the so far most detailed cartographic representation of glacier extent in Switzerland. Analysing the dependencies between topographic parameters and debris-cover fraction on the basis of individual glaciers reveals that short glaciers with a moderate mean slope and glaciers with a low median elevation tend to have high debris fractions. A change assessment between the SGI1973 and SGI2016 based on individual glacier entities affirms the largest relative area changes for small glaciers and for low-elevation glaciers, whereas the largest glaciers show small relative area changes, though large absolute changes. The analysis further indicates a tendency for glaciers with a high share of supraglacial debris to show larger relative area changes.Despite of an observed strong glacier volume loss between 2010 and 2016, the total glacier surface area of the SGI2016 is somewhat larger than reported in the last Swiss glacier inventory SGI2010. Even though both inventories were created based on swisstopo aerial photographs, the additional data, tools, resources and methodologies used by the professional cartographers digitizing glacier outlines in 3D for the SGI2016, are able to explain the counter-intuitive difference between SGI2010 and SGI2016. A direct comparison of these two datasets is thus not meaningful, but an experiment where a representative glacier sample of the SGI2010 was re-assessed based on the approaches of the SGI2016 led to an upscaled total glacier surface area of 1010 km2 for the Swiss Alps around 2010. This indicates an area loss of 49 km2 between the two last Swiss glacier inventories. As swisstopo data products are and will be regularly updated, the SGI2016 is the first step towards a consistent and accurate data product of repeated glacier inventories in six-year time intervals that promises a high comparability for individual glaciers and glacier samples.

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Pan-arctic glaciers volume changes over 1975-2019

10.5194/egusphere-egu21-8606 ◽

2021 ◽

Author(s):

Amaury Dehecq ◽

Alex Gardner ◽

Romain Hugonnet ◽

Joaquin Belart

Keyword(s):

Canadian Arctic ◽

Aerial Images ◽

The Arctic ◽

Glacier Mass Balance ◽

Russian Arctic ◽

Elevation Change ◽

Volume Changes ◽

Arctic Regions ◽

Digital Elevation

Glaciers retreat contributed to about 1/3 of the observed sea level rise since 1971 (IPCC). However, long term estimates of glaciers volume changes rely on sparse field observations and region-wide satellite observations are available mostly after 2000. The now declassified images from the American reconnaissance satellite series Hexagon (KH-9), that acquired 6 m resolution stereoscopic images from 1971 to 1986, open new possibilities for glaciers observation.Based on recently published methodology (Dehecq et al., 2020, doi: 10.3389/feart.2020.566802), we process all available KH-9 images over the Arctic (Canadian arctic, Iceland, Svalbard, Russian arctic) to generate Digital Elevation Models (DEMs) and ortho-images for the period 1974-1980. We validate the KH-9 DEMs over Iceland against elevation derived from historical aerial images acquired within a month from the satellite acquisition.Finally, we calculate the glacier elevation change between the historical DEMs and modern elevation obtained from a time series of ASTER stereo images and validated against ICESat-2 elevation. The geodetic glacier mass balance is calculated for all pan-Arctic regions and analyzed with reference to the last 20 years evolution.

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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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Ice-volume changes of selected glaciers in the Swiss Alps since the end of the 19th century

Annals of Glaciology ◽

10.3189/172756407782871701 ◽

2007 ◽

Vol 46 ◽

pp. 145-149 ◽

Cited By ~ 105

Author(s):

Andreas Bauder ◽

Martin Funk ◽

Matthias Huss

Keyword(s):

19Th Century ◽

Temporal Variations ◽

Swiss Alps ◽

Ice Age ◽

Aerial Photographs ◽

Volume Changes ◽

Thickness Change ◽

Ice Volume ◽

The 1960S ◽

The 19Th Century

AbstractThe evolution of surface topography of glaciers in the Swiss Alps is well documented with high-resolution aerial photographs repeatedly recorded since the 1960s and further back in time with topographic maps including elevation contour lines first surveyed in the mid-19th century. In order to quantify and interpret glacier changes in the Swiss Alps, time series of volume changes over the last 100–150 years have been collected. The available datasets provide a detailed spatial resolution for the retreat period since the end of the Little Ice Age. The spatial distribution as well as temporal variations of the thickness change were analyzed. A significant ice loss since the end of the 19th century was observed in the ablation area, while the changes in the accumulation area were small. We found moderate negative secular rates until the 1960s, followed by steady to positive rates for about two decades and strong ice loss starting in the 1980s which has lasted until the present. An evaluation of 19 glaciers revealed a total ice volume loss of about 13km3 since the 1870s, of which 8.7 km3 occurred since the 1920s and 3.5 km3 since 1980. Decadal mean net balance rates for the periods 1920–60, 1960–80 and 1980–present are –0.29, –0.03 and –0.53ma–1w.e., respectively.

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Glacier-specific elevation changes in parts of western Alaska

Annals of Glaciology ◽

10.3189/2015aog70a227 ◽

2015 ◽

Vol 56 (70) ◽

pp. 184-192 ◽

Cited By ~ 16

Author(s):

R. Le Bris ◽

F. Paul

Keyword(s):

Mass Balance ◽

Accurate Determination ◽

Entire Region ◽

Volume Changes ◽

Sample Mean ◽

Tidewater Glaciers ◽

Digital Elevation ◽

Elevation Changes ◽

Global Sea Level

AbstractThe meltwater from glaciers in Alaska contributes strongly to global sea-level rise, but accurate determination is challenging as only two comparatively small glaciers have long-term measurements of annual mass balance (Gulkana and Wolverine). Simple upscaling of their values to the entire region is error-prone as their representativeness is unknown and might be biased. Alternatively, differencing digital elevation models (DEMs) from two epochs provides overall volume changes for a longer period of time that can be converted to mass changes using appropriate density assumptions. Here we combine outlines from two glacier inventories to determine glacier-specific elevation changes over a 50 year period for 3180 glaciers in western Alaska using DEM differencing. This allows us to determine the representativeness of the land-terminating Gulkana and Wolverine Glaciers for the entire region and to exclude calving glaciers (marine and lacustrine) from the sample. Mean changes for all land-terminating, lake-terminating and tidewater glaciers are –0.23 ± 0.44, –0.63 ± 0.40 and –0.64 ± 0.66 m a–1, respectively, and –0.7 and –0.6 m a–1 for the two mass-balance or benchmark glaciers. Thus fortuitously their changes better represent calving glaciers and the overall mean (–0.63 ± 1.14 m a–1) than the change of land-terminating glaciers, i.e. they are not representative for their own type. Different methods of considering potential DEM artefacts provide variable mean changes but the same general result.

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Glacier changes in the Pascua-Lama region, Chilean Andes (29° S): recent mass balance and 50 yr surface area variations

The Cryosphere ◽

10.5194/tc-5-1029-2011 ◽

2011 ◽

Vol 5 (4) ◽

pp. 1029-1041 ◽

Cited By ~ 50

Author(s):

A. Rabatel ◽

H. Castebrunet ◽

V. Favier ◽

L. Nicholson ◽

C. Kinnard

Keyword(s):

Mass Balance ◽

Surface Area ◽

Monitoring Program ◽

High Elevation ◽

Aerial Photographs ◽

Late 20Th Century ◽

Surface Mass ◽

Glacier Changes ◽

Chilean Andes

Abstract. Since 2003, a monitoring program has been conducted on several glaciers and glacierets in the Pascua-Lama region of the Chilean Andes (29° S/70° W; 5000 m a.s.l.), permitting the study of glaciological processes on ice bodies in a subtropical, arid, high-elevation area where no measurements were previously available. In this paper we present: (1) six years of glaciological surface mass balance measurements from four ice bodies in the area, including a discussion of the nature of the studied glaciers and glacierets and characterization of the importance of winter mass balance to annual mass balance variability; and (2) changes in surface area of twenty ice bodies in the region since 1955, reconstructed from aerial photographs and satellite images, which shows that the total glaciated surface area reduced by ~29% between 1955 and 2007, and that the rate of surface area shrinkage increased in the late 20th century. Based on these datasets we present a first interpretation of glacier changes in relation with climatic parameters at both local and regional scales.

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