scholarly journals Recent geodetic mass balance of Monte Tronador glaciers, North Patagonian Andes

2016 ◽  
Author(s):  
Lucas Ruiz ◽  
Etienne Berthier ◽  
Maximiliano Viale ◽  
Pierre Pitte ◽  
Mariano Masiokas
Keyword(s):  
Mass Balance ◽  
Dynamic Equilibrium ◽  
Warm Season ◽  
Glacier Mass Balance ◽  
Mass Budget ◽  
Mountain Glaciers ◽  
The North ◽  
Notable Increase ◽  
Geodetic Mass Balance ◽  
Patagonian Andes

Abstract. Glaciers in the North Patagonian Andes (35°–46° S) have shown a dramatic area decline in the last decades. However, little it is known about glacier mass balance changes in this region. This study presents a geodetic mass balance estimate of Monte Tronador (41.15° S; 71.88° W) glaciers by comparing a Pléiades DEM acquired in 2012 with the SRTM X-band DEM acquired in 2000. We find a slightly negative Monte Tronador-wide mass budget of −0.17 m w.e. a-1 (range from −0.54 to 0.14 m w.e. a-1 for individual glaciers) and a slightly negative trend in glacier extent (−0.098 km2 a-1) over the 2000–2012 period. With few exceptions, debris covered valley glaciers that descend below a bedrock cliff are losing mass at higher rates, while mountain glaciers whose termini are located above this cliff are closer to mass equilibrium. Climate variations over the last decades show a notable increase in warm season temperatures in the late 1970s but limited warming afterward. These warmer conditions combined with an overall drying trend may explain the moderate ice mass loss observed at Monte Tronador. The almost balanced mass budget of mountain glaciers suggests that they are probably approaching a dynamic equilibrium with current (post-1977) climate, whereas the valley glaciers tongues will continue to retreat. The slightly negative overall mass budget of Monte Tronador glaciers contrasts with the highly negative mass balance estimates observed in the Patagonian Icefields further south.

scholarly journals Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

2017 ◽  
Vol 11 (1) ◽  
pp. 619-634 ◽  
Author(s):  
Lucas Ruiz ◽  
Etienne Berthier ◽  
Maximiliano Viale ◽  
Pierre Pitte ◽  
Mariano H. Masiokas
Keyword(s):  
Mass Balance ◽  
Dynamic Equilibrium ◽  
Warm Season ◽  
Shuttle Radar Topography Mission ◽  
Glacier Mass Balance ◽  
Mass Budget ◽  
Mountain Glaciers ◽  
Geodetic Mass Balance ◽  
Elevation Model ◽  
Patagonian Andes

Abstract. Glaciers in the northern Patagonian Andes (35–46° S) have shown a dramatic decline in area in the last decades. However, little is known about glacier mass balance changes in this region. This study presents a geodetic mass balance estimate of Monte Tronador (41.15° S; 71.88° W) glaciers by comparing a Pléiades digital elevation model (DEM) acquired in 2012 with the Shuttle Radar Topography Mission (SRTM) X-band DEM acquired in 2000. We find a slightly negative Monte-Tronador-wide mass budget of −0.17 m w.e. a−1 (ranging from −0.54 to 0.14 m w.e. a−1 for individual glaciers) and a slightly negative trend in glacier extent (−0.16 % a−1) over the 2000–2012 period. With a few exceptions, debris-covered valley glaciers that descend below a bedrock cliff are losing mass at higher rates, while mountain glaciers with termini located above this cliff are closer to mass equilibrium. Climate variations over the last decades show a notable increase in warm season temperatures in the late 1970s but limited warming afterwards. These warmer conditions combined with an overall drying trend may explain the moderate ice mass loss observed at Monte Tronador. The almost balanced mass budget of mountain glaciers suggests that they are probably approaching a dynamic equilibrium with current (post-1977) climate, whereas the valley glaciers tongues will continue to retreat. The slightly negative overall mass budget of Monte Tronador glaciers contrasts with the highly negative mass balance estimates observed in the Patagonian ice fields further south.

scholarly journals Long-range terrestrial laser scanning measurements of annual and intra-annual mass balances for Urumqi Glacier No. 1, eastern Tien Shan, China

2019 ◽  
Vol 13 (9) ◽  
pp. 2361-2383 ◽  
Author(s):  
Chunhai Xu ◽  
Zhongqin Li ◽  
Huilin Li ◽  
Feiteng Wang ◽  
Ping Zhou
Keyword(s):  
Mass Balance ◽  
Long Range ◽  
Tien Shan ◽  
Glacier Mass Balance ◽  
Surface Mass Balance ◽  
Mass Balances ◽  
Surface Mass ◽  
Mass Conversion ◽  
Geodetic Mass Balance

Abstract. The direct glaciological method provides in situ observations of annual or seasonal surface mass balance, but can only be implemented through a succession of intensive in situ measurements of field networks of stakes and snow pits. This has contributed to glacier surface mass-balance measurements being sparse and often discontinuous in the Tien Shan. Nevertheless, long-term glacier mass-balance measurements are the basis for understanding climate–glacier interactions and projecting future water availability for glacierized catchments in the Tien Shan. Riegl VZ®-6000 long-range terrestrial laser scanner (TLS), typically using class 3B laser beams, is exceptionally well suited for repeated glacier mapping, and thus determination of annual and seasonal geodetic mass balance. This paper introduces the applied TLS for monitoring summer and annual surface elevation and geodetic mass changes of Urumqi Glacier No. 1 as well as delineating accurate glacier boundaries for 2 consecutive mass-balance years (2015–2017), and discusses the potential of such technology in glaciological applications. Three-dimensional changes of ice and firn–snow bodies and the corresponding densities were considered for the volume-to-mass conversion. The glacier showed pronounced thinning and mass loss for the four investigated periods; glacier-wide geodetic mass balance in the mass-balance year 2015–2016 was slightly more negative than in 2016–2017. Statistical comparison shows that agreement between the glaciological and geodetic mass balances can be considered satisfactory, indicating that the TLS system yields accurate results and has the potential to monitor remote and inaccessible glacier areas where no glaciological measurements are available as the vertical velocity component of the glacier is negligible. For wide applications of the TLS in glaciology, we should use stable scan positions and in-situ-measured densities of snow–firn to establish volume-to-mass conversion.

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

2018 ◽  
Vol 64 (248) ◽  
pp. 917-931 ◽  
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.

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

2010 ◽  
Vol 4 (3) ◽  
pp. 1151-1194
Author(s):  
A. Fischer
Keyword(s):  
Mass Balance ◽  
Direct Method ◽  
Mean Difference ◽  
Published Data ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Direct Data ◽  
The Mean ◽  
The Difference ◽  
Geodetic Mass Balance

Abstract. Glacier mass balance is measured with the direct or the geodetic method. In this study, the geodetic mass balances of six Austrian glaciers in 19 periods between 1953 and 2006 are compared to the direct mass balances in the same periods. The mean annual geodetic mass balance for all periods is −0.5 m w.e./year. The mean difference between the geodetic and the direct data is −0.7 m w.e., the minimum −7.3 m w.e. and the maximum 5.6 m w.e. The accuracy of geodetic mass balance resulting from the accuracy of the DEMs ranges from 2 m w.e. for photogrammetric data to 0.002 m w.e. for LIDAR data. Basal melt, seasonal snow cover and density changes of the surface layer contribute up to 0.7 m w.e. for the period of 10 years to the difference to the direct method. The characteristics of published data of Griesgletscher, Gulkana Glacier, Lemon Creek glacier, South Cascade, Storbreen, Storglaciären, and Zongo Glacier is similar to these Austrian glaciers. For 26 analyzed periods with an average length of 18 years the mean difference between the geodetic and the direct data is −0.4 m w.e., the minimum −7.2 m w.e. and the maximum 3.6 m w.e. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Specific glaciers show specific trends of the difference between the direct and the geodetic data according to their type and state. In conclusion, geodetic and direct mass balance data are complementary, but differ systematically.

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

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.

scholarly journals Closing the mass budget of a tidewater glacier: the example of Kronebreen, Svalbard

2019 ◽  
Vol 65 (249) ◽  
pp. 136-148 ◽  
Author(s):  
CESAR DESCHAMPS-BERGER ◽  
CHRISTOPHER NUTH ◽  
WARD VAN PELT ◽  
ETIENNE BERTHIER ◽  
JACK KOHLER ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mass Balance ◽  
Total Mass ◽  
Continuity Equation ◽  
Recent Period ◽  
Mass Budget ◽  
Tidewater Glacier ◽  
Geodetic Mass Balance ◽  
Frontal Ablation

ABSTRACTIn this study, we combine remote sensing, in situ and model-derived datasets from 1966 to 2014 to calculate the mass-balance components of Kronebreen, a fast-flowing tidewater glacier in Svalbard. For the well-surveyed period 2009–2014, we are able to close the glacier mass budget within the prescribed errors. During these 5 years, the glacier geodetic mass balance was −0.69 ± 0.12 m w.e. a−1, while the mass budget method led to a total mass balance of −0.92 ± 0.16 m w.e. a−1, as a consequence of a strong frontal ablation (−0.78 ± 0.11 m w.e. a−1), and a slightly negative climatic mass balance (−0.14 ± 0.11 m w.e. a−1). The trend towards more negative climatic mass balance between 1966–1990 (+0.20 ± 0.05 m w.e. a−1) and 2009–2014 is not reflected in the geodetic mass balance trend. Therefore, we suspect a reduction in ice-discharge in the most recent period. Yet, these multidecadal changes in ice-discharge cannot be measured from the available observations and thus are only estimated with relatively large errors as a residual of the mass continuity equation. Our study presents the multidecadal evolution of the dynamics and mass balance of a tidewater glacier and illustrates the errors introduced by inferring one unmeasured mass-balance component from the others.

Garabashi glacier (Caucasus) mass changes estimated from glaciological and geodetic mass balance measurements

2020 ◽  
Author(s):  
Stanislav Kutuzov ◽  
Andrey Smirnov ◽  
Gennady Nosenko ◽  
Ivan Lavrentiev ◽  
Aleksei Poliukhov ◽  
...  
Keyword(s):  
Mass Balance ◽  
Climate Changes ◽  
Snow Accumulation ◽  
Shortwave Radiation ◽  
North Caucasus ◽  
Pronounced Increase ◽  
Surface Mass ◽  
Mountain Glaciers ◽  
The North ◽  
Area Reduction

&lt;p&gt;The ice-covered Europe's largest volcanic massif Elbrus (5,642 m) is a unique object for studying the reaction of mountain glaciers to climate changes. Elbrus glacial system contains more than 10% of the total ice volume in the Greater Caucasus. Elbrus glaciers influence on the recreation development. The rivers runoff from the Elbrus glaciers irrigates agricultural lands on steppe plains of the North Caucasus.&lt;/p&gt;&lt;p&gt;The rate of glacier reduction in the late XX - early XXI centuries has increased significantly and in 1997-2017 Elbrus have lost 23% of its volume. Despite a number of glacier studies the mechanisms and quantitative characteristics surface mass exchange on Elbrus are still uncertain. Mass balance calculations were based on limited data. In particular, amount and distribution of snow accumulation, mass balance sensitivity to meteorological parameters under dramatic climate changes and other parameters remained unknown.&lt;/p&gt;&lt;p&gt;Here we present the results of the detailed analysis of Garabashi glacier mass changes in 1982-2019 using glaciological and geodetic methods. Based on the new data of snow and ablation distribution the mass balance measurement system of Garabashi glacier was improved in 2018-2019. The mass balance over the studied period was also modelled using both temperature-index and distributed energy mass balance models calibrated by in situ measurements and albedo estimates from the remote sensing.&lt;/p&gt;&lt;p&gt;The mass balance of the Garabashi glacier was close to zero or slightly positive in 1982-1997 and the cumulative mass balance was 1 m w.e. in this period. In 1997-2017 Garabashi glacier lost 12.58 m w.e. and 12.92 &amp;#177; 0.95 m w.e. (&amp;#8722;0.63 and &amp;#8722;0.65 &amp;#177; 0.05 m w.e. a&amp;#8722;1) estimated by glaciological and geodetic method, respectively. Additional -1.7 m w.e. were lost in 2018-2019. This resulted in an area reduction by 14% and a loss of 27% of glacier volume. The observed glacier recession is driven by the pronounced increase in summer temperatures, especially since 1995, which is accompanied by nearly consistent precipitation rates The increase in incoming shortwave radiation, also played a significant role in the accelerated mass loss of glaciers in Caucasus. This study was supported by the RFBR grant 18-05-00838 a&lt;/p&gt;

scholarly journals Glaciological and geodetic mass balance of ten long-term glaciers in Norway

2015 ◽  
Vol 9 (6) ◽  
pp. 6581-6626 ◽  
Author(s):  
L. M. Andreassen ◽  
H. Elvehøy ◽  
B. Kjøllmoen ◽  
R. V. Engeset
Keyword(s):  
Mass Balance ◽  
Uncertainty Assessment ◽  
Glacier Mass Balance ◽  
Surface Mass ◽  
Independent Observations ◽  
Observation Series ◽  
Field Notes ◽  
Geodetic Mass Balance ◽  
Year 2000

Abstract. The glaciological and geodetic methods provide independent observations of glacier mass balance. The glaciological method measures the surface mass balance, on a seasonal or annual basis, whereas the geodetic method measures surface, internal and basal mass balances, over a period of years or decades. In this paper, we reanalyse the 10 glaciers with long-term mass balance series in Norway. The reanalysis includes (i) homogenisation of both glaciological and geodetic observation series, (ii) uncertainty assessment, (iii) estimates of generic differences including estimates of internal and basal melt, (iv) validation, and (v) partly calibration of mass balance series. This study comprises an extensive set of data (454 mass balance years, 34 geodetic surveys and large volumes of supporting data, such as metadata and field notes). In total, 21 periods of data were compared and the results show discrepancies between the glaciological and geodetic methods for some glaciers, which in part are attributed to internal and basal ablation and in part to inhomogeneity in the data processing. Deviations were smaller than 0.2 m w.e. a−1 for 12 out of 21 periods. Calibration was applied to seven out of 21 periods, as the deviations were larger than the uncertainty. The reanalysed glaciological series shows a more consistent signal of glacier change over the period of observations than previously reported: six glaciers had a significant mass loss (14–22 m w.e.) and four glaciers were nearly in balance. All glaciers have lost mass after year 2000. More research is needed on the sources of uncertainty, to reduce uncertainties and adjust the observation programmes accordingly. The study confirms the value of carrying out independent high-quality geodetic surveys to check and correct field observations.

scholarly journals ICESat laser altimetry over small mountain glaciers

2016 ◽  
Author(s):  
D. Treichler ◽  
A. Kääb
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
Srtm Dem ◽  
Elevation Change ◽  
Laser Altimetry ◽  
Glacier Surface ◽  
Mountain Glaciers ◽  
Southern Norway ◽  
Spatially Varying

Abstract. Using sparsely glaciated southern Norway as a case study, we assess the potential and limitations of ICESat laser altimetry for analysing regional glacier elevation change in rough mountain terrain. Differences between ICESat GLAS elevations and reference elevation data are plotted over time to derive a glacier surface elevation trend for the ICESat acquisition period 2003–2008. We find spatially varying biases between ICESat and three tested digital elevation models (DEMs): the Norwegian national DEM, SRTM DEM and a high resolution LiDAR DEM. For regional glacier elevation change, the spatial inconsistency of reference DEMs – a result of spatio-temporal merging – has the potential to significantly affect or dilute trends. Elevation uncertainties of all three tested DEMs exceed ICESat elevation uncertainty by an order of magnitude, and are thus limiting the accuracy of the method, rather than ICESat uncertainty. After correction of reference elevation bias, we find that ICESat provides a robust and realistic estimate of a moderately negative glacier mass balance of around −0.30 m &amp;pm; 0.06 ice per year. This regional estimate agrees well with the heterogeneous but overall negative in-situ glacier mass balance observed in the area. ICESat matches glacier size distribution of the study area well and measures also small ice patches not commonly monitored in-situ. The sample is large enough for spatial and thematic subsetting. Vertical offsets to ICESat elevations vary for different glaciers in southern Norway due to spatially inconsistent reference DEM age. We introduce a per-glacier correction that removes these spatially varying offsets, and considerably increases trend significance. Only after application of this correction do individual campaigns also fit to observed in-situ glacier mass balance. Our correction has the potential to improve glacier trend significance also for other causes of spatially varying vertical offsets, for instance due to radar penetration into ice and snow for the SRTM DEM, or as a consequence from mosaicking and merging that is common for national or global DEMs.

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