scholarly journals Thickness and geodetic mass balance changes for the Triglav Glacier (southeastern Alps) from 1952 to 2016

2020 ◽  
Vol 60 (2) ◽  
pp. 155-173 ◽  
Author(s):  
Mihaela Triglav Čekada ◽  
Matija Zorn
Keyword(s):  
Mass Balance ◽  
Glacier Area ◽  
Volume Changes ◽  
Specific Mass ◽  
Maximum Thickness ◽  
Lidar Measurements ◽  
Julian Alps ◽  
The Mean ◽  
Geodetic Mass Balance

Various geodetic and lidar measurements performed on the Triglav Glacier (Julian Alps, Slovenia) make it possible to study not only the extent of the glacier but also changes in its thickness and volume. These measurements also make it possible to calculate the geodetic mass balance of the glacier. Thickness and volume changes were calculated using glacier area measurements from 1952, 1975, and 1992, and annually between 1999 and 2016. The mean thickness decreased from 39.2m in 1952 to 2.45m in 2012. The maximum thickness decreased from 48.3 m in 1952 to 5.2 m in 2007. The mean specific mass balance was calculated for the area of 1 hectare that the glacier covered in 2016. From 1952 to 2016, the annual specific mass balance was −0.45m w.e.a−1.

scholarly journals Strong ELA increase causes fast mass loss of glaciers in central Spitsbergen

2015 ◽  
Vol 9 (6) ◽  
pp. 6153-6185
Author(s):  
J. Małecki
Keyword(s):  
Mass Balance ◽  
Ice Age ◽  
The Arctic ◽  
Glacier Area ◽  
Equilibrium Line Altitude ◽  
Digital Elevation ◽  
Glacier Changes ◽  
Central Regions ◽  
The Mean ◽  
Geodetic Mass Balance

Abstract. Svalbard is a heavily glacier covered archipelago in the Arctic. Its central regions, including Dickson Land (DL), are occupied by small alpine glaciers, which post-Little Ice Age (LIA) changes remain only sporadically investigated. This study presents a comprehensive analysis of glacier changes in DL based on inventories compiled from topographic maps and digital elevation models (DEMs) for LIA, 1960's, 1990 and 2009/11. The 37.9 ± 12.1 % glacier area decrease in DL (i.e. from 334.1 ± 38.4 km2 during LIA to 207.4 ± 4.6 km2 in 2009/11) has been primarily caused by accelerating termini retreat. The mean 1990–2009/11 geodetic mass balance of glaciers was -0.70 ± 0.06 m a-1 (-0.63 ± 0.05 m w.e. a-1), being one of the most negative from Svalbard regional means known from the literature. If the same figure was to be applied for other similar regions of central Spitsbergen, that would result in a considerable contribution to total Svalbard mass balance despite negligible proportion to total glacier area. Glacier changes in Dickson Land were linked to dramatic equilibrium line altitude (ELA) shift, which in the period 1990–2009/11 has been located ca. 500 m higher than required for steady-state. The mass balance of central Spitsbergen glaciers seems to be therefore more sensitive to climate change than previously thought.

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

2015 ◽  
Vol 9 (2) ◽  
pp. 525-540 ◽  
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.

scholarly journals Reconstruction of the Historical (1750–2020) Mass Balance of Bordu, Kara-Batkak and Sary-Tor Glaciers in the Inner Tien Shan, Kyrgyzstan

2021 ◽  
Vol 9 ◽  
Author(s):  
Lander Van Tricht ◽  
Chloë Marie Paice ◽  
Oleg Rybak ◽  
Rysbek Satylkanov ◽  
Victor Popovnin ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Climatic Conditions ◽  
Tien Shan ◽  
Ice Age ◽  
Balance Model ◽  
Mass Balances ◽  
Specific Mass ◽  
The Future ◽  
The Mean

The mean specific mass balance of a glacier represents the direct link between a glacier and the local climate. Hence, it is intensively monitored throughout the world. In the Kyrgyz Tien Shan, glaciers are of crucial importance with regard to water supply for the surrounding areas. It is therefore essential to know how these glaciers behave due to climate change and how they will evolve in the future. In the Soviet era, multiple glaciological monitoring programs were initiated but these were abandoned in the nineties. Recently, they have been re-established on several glaciers. In this study, a reconstruction of the mean specific mass balance of Bordu, Kara-Batkak and Sary-Tor glaciers is obtained using a surface energy mass balance model. The model is driven by temperature and precipitation data acquired by combining multiple datasets from meteorological stations in the vicinity of the glaciers and tree rings in the Kyrgyz Tien Shan between 1750 and 2020. Multi-annual mass balance measurements integrated over elevation bands of 100 m between 2013 and 2020 are used for calibration. A comparison with WGMS data for the second half of the 20th century is performed for Kara-Batkak glacier. The cumulative mass balances are also compared with geodetic mass balances reconstructed for different time periods. Generally, we find a close agreement, indicating a high confidence in the created mass balance series. The last 20 years show a negative mean specific mass balance except for 2008–2009 when a slightly positive mass balance was found. This indicates that the glaciers are currently in imbalance with the present climatic conditions in the area. For the reconstruction back to 1750, this study specifically highlights that it is essential to adapt the glacier geometry since the end of the Little Ice Age in order to not over- or underestimate the mean specific mass balance. The datasets created can be used to get a better insight into how climate change affects glaciers in the Inner Tien Shan and to model the future evolution of these glaciers as well as other glaciers in the region.

scholarly journals Mass balances of Yala and Rikha Samba glaciers, Nepal, from 2000 to 2017

2021 ◽  
Vol 13 (8) ◽  
pp. 3791-3818
Author(s):  
Dorothea Stumm ◽  
Sharad Prasad Joshi ◽  
Tika Ram Gurung ◽  
Gunjan Silwal
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Water Resource Management ◽  
Important Variable ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Monitoring Strategies ◽  
Length Changes ◽  
The Mean ◽  
Geodetic Mass Balance

Abstract. The glacier mass balance is an important variable to describe the climate system and is used for various applications like water resource management or runoff modelling. The direct or glaciological method and the geodetic method are the standard methods to quantify glacier mass changes, and both methods are an integral part of international glacier monitoring strategies. In 2011, we established two glacier mass-balance programmes on Yala and Rikha Samba glaciers in the Nepal Himalaya. Here we present the methods and data of the directly measured annual mass balances for the first six mass-balance years for both glaciers from 2011/2012 to 2016/2017. For Yala Glacier we additionally present the directly measured seasonal mass balance from 2011 to 2017, as well as the mass balance from 2000 to 2012 obtained with the geodetic method. In addition, we analysed glacier length changes for both glaciers. The directly measured average annual mass-balance rates of Yala and Rikha Samba glaciers are −0.80 ± 0.28 and −0.39 ± 0.32 m w.e. a−1, respectively, from 2011 to 2017. The geodetically measured annual mass-balance rate of Yala Glacier based on digital elevation models from 2000 and 2012 is −0.74 ± 0.53 m w.e. The cumulative mass loss for the period 2011 to 2017 for Yala and Rikha Samba glaciers is −4.80 ± 0.69 and −2.34 ± 0.79 m w.e., respectively. The mass loss on Yala Glacier from 2000 to 2012 is −8.92 ± 6.33 m w.e. The winter balance of Yala Glacier is positive, and the summer balance is negative in every investigated year. The summer balance determines the annual balance. Compared to regional mean geodetic mass-balance rates in the Nepalese Himalaya, the mean mass-balance rate of Rikha Samba Glacier is in a similar range, and the mean mass-balance rate of Yala Glacier is more negative because of the small and low-lying accumulation area. During the study period, a change of Yala Glacier's surface topography has been observed with glacier thinning and downwasting. The retreat rates of Rikha Samba Glacier are higher than for Yala Glacier. From 1989 to 2013, Rikha Samba Glacier retreated 431 m (−18.0 m a−1), and from 1974 to 2016 Yala Glacier retreated 346 m (−8.2 m a−1). The data of the annual and seasonal mass balances, point mass balance, geodetic mass balance, and length changes are accessible from the World Glacier Monitoring Service (WGMS, 2021), https://doi.org/10.5904/wgms-fog-2021-05.

scholarly journals Comparison of glaciological and volumetric mass balance measurements at Storglaciären, Sweden

2010 ◽  
Vol 4 (1) ◽  
pp. 381-408 ◽  
Author(s):  
M. Zemp ◽  
P. Jansson ◽  
P. Homlund ◽  
I. Gärtner-Roer ◽  
T. Koblet ◽  
...  
Keyword(s):  
Mass Balance ◽  
Uncertainty Assessment ◽  
Aerial Photographs ◽  
Data Series ◽  
Mass Balances ◽  
Volume Changes ◽  
Systematic Uncertainties ◽  
In Situ Observations ◽  
The Mean

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 used the resulting aerial photographs to produce glaciological 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 1959–1969, 1969–1980, 1980–1990, and 1990–1999. We compare 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 0.9 m w.e. for the period of 1959–1969 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, hence, do not require an adjustment of the glaciological data series.

First geodetic mass balance estimate of the bulk of the South Shetland Islands ice caps

2021 ◽  
Author(s):  
Kaian Shahateet ◽  
Thorsten Seehaus ◽  
Francisco Navarro ◽  
Matthias Braun
Keyword(s):  
Mass Balance ◽  
Data Availability ◽  
South Shetland Islands ◽  
Close Monitoring ◽  
The South ◽  
Specific Mass ◽  
Shetland Islands ◽  
Ice Caps ◽  
Geodetic Mass Balance ◽  
Interferometric Sar

<p>The Antarctic Peninsula ice sheet is an important contributor to sea-level rise and the glaciers in its peripheral islands have a large potential to increase their contribution under a warming climate. This region has undergone a complex history of climate change during recent decades, which justifies a close monitoring of their glaciers. The South Shetland Islands (SSI) is one of the northernmost archipelagos in this region, but it is lacking a geodetic mass balance (GMB) calculation for the entire archipelago. We have estimated the GMB of the SSI over a 3-4 years period within 2013-2017 (depending on the data availability for each island). Our estimation is based on remotely-sensed multispectral and interferometric SAR data covering 96% of the glacierized areas of the islands considered in our study, and 73% of the total glacierized area of the SSI archipelago (Elephant, Clarence and Smith Islands were excluded due to overly large slopes for SAR or limited input data). Our Results show a close-to-balance overall status during the analyzed period, with specific mass balances ranging from -0.680±0.071 to 0.209±0.025 m w.e. a<sup>-1</sup> on Low and Livingston islands, respectively. The average specific mass balance for the whole area is -0.064±0.015 m w.e. a<sup>-1</sup>, representing an ice mass loss of 0.144±0.035 Gt a<sup>-1</sup>. This result is consistent with the cooling trend observed in the region between 1998 and 2017, and with the mass balance estimates by the glaciological method performed in various glaciers in the AP region (and the SSI in particular).</p>

scholarly journals Area, volume and mass changes of southeast Vatnajökull ice cap, Iceland, from the Little Ice Age maximum in the late 19th century to 2010

2014 ◽  
Vol 8 (5) ◽  
pp. 4681-4735 ◽  
Author(s):  
H. Hannesdóttir ◽  
H. Björnsson ◽  
F. Pálsson ◽  
G. Aðalgeirsdóttir ◽  
S. Guðmundsson
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Relative Volume ◽  
Aerial Images ◽  
Ice Age ◽  
Volume Changes ◽  
Data Set ◽  
Bedrock Topography ◽  
Ice Cap ◽  
Geodetic Mass Balance

Abstract. Area and volume changes and the average geodetic mass balance of the non-surging outlet glaciers of 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) have been compiled from glacial geomorphological features, historical photographs, maps, aerial images, DGPS measurements and a LiDAR survey. Given the mapped bedrock topography we estimate relative volume changes since the end of the Little Ice Age (LIA) ~1890. The variable dynamic response of the outlets, assumed to have experienced similar climate forcing, is related to their different hypsometry, bedrock topography, and the presence of proglacial lakes. In the post-LIA period the glacierized area decreased by 164 km2 and the glaciers had lost 10–30% of their ~1890 area by 2010. 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 0.154 ± 0.02 mm of sea level rise. The relative 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 rate of mass loss was most negative in the period 2002–2010, on average −1.34 ± 0.12 m w.e. a−1, which lists among the most negative mass balance values recorded worldwide in the early 21st century. From the data set of volume and area of the outlets, spanning the 120 years post-LIA period, we evaluate the parameters of a volume-area power law scaling relationship.

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

2011 ◽  
Vol 5 (1) ◽  
pp. 107-124 ◽  
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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