scholarly journals Glacier variations at Aru Co in western Tibet from 1971 to 2016 derived from remote-sensing data

2018 ◽  
Vol 64 (245) ◽  
pp. 397-406 ◽  
Author(s):  
ZHEN ZHANG ◽  
SHIYIN LIU ◽  
YONG ZHANG ◽  
JUNFENG WEI ◽  
ZONGLI JIANG ◽  
...  
Keyword(s):  
Mass Balance ◽  
Remote Sensing Data ◽  
Topographic Maps ◽  
Glacier Area ◽  
Human Beings ◽  
Positive Mass ◽  
Landsat Images ◽  
Pressure Melting ◽  
Geodetic Mass Balance ◽  
Sustained Increase

ABSTRACTTwin glaciers collapsed in 2016 near Aru Co, western Tibet and caused extreme loss to human beings. In this study, we attempted to track the dynamics of glaciers in the region, for example the glacier area and mass changes in Aru Co for the period 1971–2016, which were determined using topographic maps and Landsat images and ASTER-derived DEMs (2011–16), the Shuttle Radar Terrain Mission DEM (2000) and topographic maps (1971). Our results showed that the glacier area of Aru Co decreased by −0.4 ± 4.1% during 1971–2016. The geodetic mass-balance results showed that the glaciers in Aru Co lost mass at a rate of −0.15 ± 0.30 m w.e. a−1 during 1971–99, while they gained mass at a rate of 0.33 ± 0.61 m w.e. a−1 for the period 1999–2016. The twin glaciers experienced a larger negative mass budget than the others in the region before 1999. This process produced large amounts of meltwater, followed by a sustained increase in the meltwater on the pressure melting point, possibly in response to a period of positive mass balance (1999–2016) and then, transferred to the glacier bed until the glaciers collapsed.

scholarly journals Glacier mass balance over the central Nyainqentanglha Range during recent decades derived from remote-sensing data

2019 ◽  
Vol 65 (251) ◽  
pp. 422-439 ◽  
Author(s):  
KUNPENG WU ◽  
SHIYIN LIU ◽  
ZONGLI JIANG ◽  
JUNLI XU ◽  
JUNFENG WEI
Keyword(s):  
Mass Balance ◽  
Remote Sensing Data ◽  
Shuttle Radar Topography Mission ◽  
Topographic Maps ◽  
Glacier Mass Balance ◽  
Glacier Area ◽  
Ice Surface ◽  
Digital Elevation ◽  
Elevation Changes ◽  
Elevation Model

ABSTRACTTo obtain information on changes in glacier mass balance in the central Nyainqentanglha Range, a comprehensive study was carried out based on digital-elevation models derived from the 1968 topographic maps, the Shuttle Radar Topography Mission DEM (2000) and TerraSAR-X/TanDEM-X (2013). Glacier area changes between 1968 and 2016 were derived from topographic maps and Landsat OLI images. This showed the area contained 715 glaciers, with an area of 1713.42 ± 51.82 km2, in 2016. Ice cover has been shrinking by 0.68 ± 0.05% a−1 since 1968. The glacier area covered by debris accounted for 11.9% of the total and decreased in the SE–NW directions. Using digital elevation model differencing and differential synthetic aperture radar interferometry, a significant mass loss of 0.46 ± 0.10 m w.e. a−1 has been recorded since 1968; mass losses accelerated from 0.42 ± 0.20 m w.e. a−1 to 0.60 ± 0.20 m w.e. a−1 between 1968–2000 and 2000–2013, with thinning noticeably greater on the debris-covered ice than the clean ice. Surface-elevation changes can be influenced by ice cliffs, as well as debris cover and land- or lake-terminating glaciers. Changes showed spatial and temporal heterogeneity and a substantial correlation with climate warming and decreased precipitation.

scholarly journals Estimating the Changes in Glaciers and Glacial Lakes in the Xixabangma Massif, Central Himalayas, between 1974 and 2018 from Multisource Remote Sensing Data

2021 ◽  
Vol 13 (19) ◽  
pp. 3903
Author(s):  
Yingzheng Wang ◽  
Jia Li ◽  
Lixin Wu ◽  
Lei Guo ◽  
Jun Hu ◽  
...  
Keyword(s):  
Mass Balance ◽  
Remote Sensing Data ◽  
Water Levels ◽  
Glacial Lake ◽  
Glacier Mass Balance ◽  
Lake Area ◽  
Glacier Area ◽  
Glacial Lakes ◽  
Landsat Images ◽  
Massif Central

The continuous melting of valley glaciers can impact the water levels of glacial lakes and create glacial lake outburst floods (GLOFs). The Xixabangma massif is one of the most populated areas in the Himalayas and has suffered from multiple GLOFs. To estimate the glacier melting rate in the past four decades and analyze the outburst risk of glacial lakes in the Xixabangma massif, we determined changes in glacier mass balance, glacier area and glacial lake area based on KH-9 images, TanDEM-X images, Landsat images, SRTM DEM and ICESat-2 elevations. Our results show that, from 1974 to 2018, the total glacier area shrank from 954.01 km2 to 752.46 km2, whereas the total glacial lake area grew from 20.90 km2 to 38.71 km2. From 1974 to 2000, 2000 to 2013 and 2013 to 2018, the region-wide glacier mass balance values were −0.16 m w.e./a, −0.31 m w.e./a and −0.29 m w.e./a, respectively. Three glacial lakes, named Gangxico, Galongco and Jialongco, respectively, expanded by 127.14%, 373.45% and 436.36% from 1974 to 2018, and the mass loss rates of their parent glaciers from 2000 to 2013 increased by 81.72%, 122.22% and 160.00% relative to those during 1974 to 2000. The dams of these three lakes are unstable, and their drainage valleys directly connect to a major town and its infrastructure. Due to current high-water levels, possible external events such as ice collapse, landslide, heavy rainfall and earthquakes can easily trigger GLOFs. Hence, we deemed that the Gangxico, Galongco and Jialongco glacial lakes are dangerous and require special attention.

scholarly journals Mass balance of Himalayan glaciers using AAR and ELA methods

1992 ◽  
Vol 38 (128) ◽  
pp. 101-104 ◽  
Author(s):  
Anil V. Kulkarni
Keyword(s):  
Mass Balance ◽  
Correlation Coefficients ◽  
Western Himalaya ◽  
Positive Mass ◽  
Landsat Images ◽  
Equilibrium Line Altitude ◽  
Zero Mass ◽  
Himalayan Glaciers ◽  
Landsat Satellite ◽  
Accumulation Area Ratio

AbstractThe accumulation area ratio (AAR) for Himalayan glaciers representing zero mass balance is substantially lower than for North America and Europe. Regression analysis suggests 0.44 for the AAR representing zero mass balance in the western Himalaya. A good correlation was observed when this method was applied to individual glaciers such as Gara and Gor-Garang in Himachal Pradesh, India. The correlation coefficients (r), using 6 and 7 years of data, respectively, were 0.88 and 0.96 for Gara and Gor-Garang Glaciers, respectively. However, when data from six western Himalayan glaciers were correlated, the correlation was 0.74. The AAR was also estimated by using Landsat images which can be useful in obtaining a trend in mass balance for a large number of Himalayan glaciers for which very little information exists.A higher correlation was observed between equilibrium-line altitude (ELA) and mass balance. The field data from Gara and Gor-Garang Glaciers shows a high correlation coefficient, i.e. −0.92 and −0.94, respectively. The ELA values obtained from the Landsat satellite images combined with topographic maps suggest positive mass balance for the year 1986–87 and negative for 1987–88.

scholarly journals Investigating the Recent Surge in the Monomah Glacier, Central Kunlun Mountain Range with Multiple Sources of Remote Sensing Data

2020 ◽  
Vol 12 (6) ◽  
pp. 966 ◽  
Author(s):  
Lei Guo ◽  
Jia Li ◽  
Lixin Wu ◽  
Zhiwei Li ◽  
Yanyang Liu ◽  
...  
Keyword(s):  
Remote Sensing Data ◽  
Mountain Range ◽  
Multiple Sources ◽  
Landsat Images ◽  
Kunlun Mountain ◽  
Slow Expansion ◽  
Length Changes ◽  
Pressure Melting ◽  
Mass Accumulation ◽  
Alos Prism

Several glaciers in the Bukatage Massif are surge-type. However, previous studies in this region focused on glacier area and length changes, and more information is needed to support the deep analysis of glacier surge. We determined changes in glacier thickness, motion, and surface features in this region based on TanDEM-X, ALOS/PRISM, Sentinel-1A, and Landsat images. Our results indicated that the recent surge of the Monomah Glacier, the largest glacier in the Bukatage Massif, started in early 2009 and ceased in late 2016. From 2009 to 2016, its area and length respectively increased by 6.27 km2 and 1.45 km, and its ice tongue experienced three periods of changes: side broadening (2009–2010), rapid advancing (2010–2013), and slow expansion (2013–2016). During 2000–2012, its accumulation zone was thinned by 50 m, while its ice tongue was thickened by 90 m. During 2015–2017, its flow velocity reduced from 1.2 to 0.25 m/d, and the summer velocities were much higher than winter velocities. We conclude that the recent Monomah Glacier surge is thermal-controlled. The subglacial temperature rose to the pressure-melting point because of substantial mass accumulation, and then the increased basal meltwater caused the surge.

scholarly journals Mass balance of Himalayan glaciers using AAR and ELA methods

1992 ◽  
Vol 38 (128) ◽  
pp. 101-104 ◽  
Author(s):  
Anil V. Kulkarni
Keyword(s):  
Mass Balance ◽  
Correlation Coefficients ◽  
Western Himalaya ◽  
Positive Mass ◽  
Landsat Images ◽  
Equilibrium Line Altitude ◽  
Zero Mass ◽  
Himalayan Glaciers ◽  
Landsat Satellite ◽  
Accumulation Area Ratio

AbstractThe accumulation area ratio (AAR) for Himalayan glaciers representing zero mass balance is substantially lower than for North America and Europe. Regression analysis suggests 0.44 for the AAR representing zero mass balance in the western Himalaya. A good correlation was observed when this method was applied to individual glaciers such as Gara and Gor-Garang in Himachal Pradesh, India. The correlation coefficients (r), using 6 and 7 years of data, respectively, were 0.88 and 0.96 for Gara and Gor-Garang Glaciers, respectively. However, when data from six western Himalayan glaciers were correlated, the correlation was 0.74. The AAR was also estimated by using Landsat images which can be useful in obtaining a trend in mass balance for a large number of Himalayan glaciers for which very little information exists.A higher correlation was observed between equilibrium-line altitude (ELA) and mass balance. The field data from Gara and Gor-Garang Glaciers shows a high correlation coefficient, i.e. −0.92 and −0.94, respectively. The ELA values obtained from the Landsat satellite images combined with topographic maps suggest positive mass balance for the year 1986–87 and negative for 1987–88.

scholarly journals Glacier change in Norway since the 1960s – an overview of mass balance, area, length and surface elevation changes

2020 ◽  
Vol 66 (256) ◽  
pp. 313-328 ◽  
Author(s):  
Liss M. Andreassen ◽  
Hallgeir Elvehøy ◽  
Bjarne Kjøllmoen ◽  
Joaquín M. C. Belart
Keyword(s):  
Mass Balance ◽  
Large Scale ◽  
Surface Elevation ◽  
Positive Mass ◽  
Area Reduction ◽  
Surface Elevation Change ◽  
Elevation Changes ◽  
Geodetic Mass Balance ◽  
The 1960S ◽  
Large Scale Atmospheric Circulation

AbstractIn this paper, we give an overview of changes in area, length, surface elevation and mass balance of glaciers in mainland Norway since the 1960s. Frontal advances have been recorded in all regions except the northernmost glaciers in Troms and Finnmark (Storsteinsfjellbreen, Lyngen and Langfjordjøkelen). More than half of the observed glaciers, 27 of 49, had marked advances in the 1990s. The glaciological mass-balance values for the period 1962–2018, where 43 glaciers have been measured, show great inter-annual variability. The results reveal accelerated deficit since 2000, the most negative decade being 2001–2010. Some years with a positive mass balance (or less negative) after 2010s can be attributed to variations in large-scale atmospheric circulation. A surface elevation change and geodetic mass balance were calculated for a sample of 131 glaciers covering 817 km2 in the ‘1960s’ and 734 km2 in the ‘2010s’, giving an area reduction of 84 km2, or 10%. The sample covers many of the largest glaciers in Norway, and they had an overall change in surface elevation of −15.5 m for the ~50 year period. Converted to a geodetic mass balance this gives a mean mass balance of −0.27 ± 0.05 m w.e. a−1.

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.

Can the mass balance of the entire glacier area of the Tien Shan be estimated?

1992 ◽  
Vol 16 ◽  
pp. 173-179
Author(s):  
M.B. Dyurgerov ◽  
M.G. Kunakhovitch ◽  
V.N. Mikhalenko ◽  
A. M. Sokalskaya ◽  
V. A. Kuzmichenok
Keyword(s):  
Mass Balance ◽  
Vertical Profile ◽  
River Basins ◽  
Annual Runoff ◽  
Snow Accumulation ◽  
Tien Shan ◽  
Exponential Dependence ◽  
Glacier Area ◽  
Equilibrium Line Altitude ◽  
Boundary Area

The total area of glacierization of the Tien Shan in the boundary area of the USSR is about 8000 km2. The computation of mass balance was determined for this area in 12 river basins.In computation procedure, the vertical profile of snow accumulation in these regions and exponential dependence of variation of ablation with altitude are used. Thus the mass balance in each basin, bn, was calculated on the basis of these curves and represented in its relation with the equilibrium line altitude (ELA). It is shown that the relation ELA = f(bn) is linear when the range of bn values is close to zero, and in all altitude intervals this relation can be described by hypsographic curves, in all basins bn positive up to an ELA elevation of 3450 to 3500 m a.s.l. For average annual altitude of ELA, bn is negative for all regions. So the glaciers of these mountains add about 4 km3 of water to the total annual runoff.

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.

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