Changes in glacier extent and surface elevations in the Depuchangdake region of northwestern Tibet, China

2016 ◽  
Vol 85 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Zhiguo Li ◽  
Lide Tian ◽  
Hongbo Wu ◽  
Weicai Wang ◽  
Shuhong Zhang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Remote Sensing Data ◽  
Shuttle Radar Topography Mission ◽  
Thematic Mapper ◽  
Glacier Retreat ◽  
Maximum Temperature ◽  
Glacier Mass Balance ◽  
Laser Altimeter ◽  
Total Mass Loss ◽  
Elevation Model

Remote sensing data, including those from Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM +), the Shuttle Radar Topography Mission Digital Elevation Model (SRTM4.1 DEM), and the Geoscience Laser Altimeter System Ice, Cloud, and Land Elevation Satellite (Glas/ICESat), show that from 1991 to 2013 the glacier area in the Depuchangdake region of northwestern Tibet decreased from 409 to 393 km2, an overall loss of 16 km2, or 3.9% of the entire 1991 glacial area. The mean glacier-thinning rate was − 0.40 ± 0.16 m equivalent height of water per year (w.e./yr), equating to a glacier mass balance of − 0.16 ± 0.07 km3 w.e./yr. Total mass loss from 2003 to 2009 was − 1.13 ± 0.46 km3. Glacier retreat likely reflects increases in annual total radiation, annual positive degree days, and maximum temperature, with concurrent increases in precipitation insufficient to replenish glacial mass loss. The rate of glacier retreat in Depuchangdake is less than that for Himalayan glaciers in Indian monsoon-dominated areas, but greater than that for Karakoram glaciers in mid-latitude westerly-dominated areas. Glacier type, climate zone, and climate change all impact on the differing degrees of long-term regional glacial change rate; however, special glacier distribution forms can sometimes lead to exceptional circumstances.

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 Recent glacier mass balance and area changes in the Kangri Karpo Mountain derived from multi-sources of DEMs and glacier inventories

2017 ◽  
Author(s):  
Wu Kunpeng ◽  
Liu Shiyin ◽  
Jiang Zongli ◽  
Xu Junli ◽  
Wei Junfeng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Loss ◽  
Shuttle Radar Topography Mission ◽  
Glacier Mass Balance ◽  
Labor Costs ◽  
Digital Elevation ◽  
Increase Risk ◽  
Elevation Changes ◽  
Length Changes ◽  
Global Mean Sea Level

Abstract. Due to the effect of Indian monsoon, the Kangri Karpo Mountain, located in southeast Tibetan Plateau, is the most humid region of Tibetan Plateau, and become one of the most important and concentrated regions with maritime (temperate) glaciers development. Glacier mass loss in Kangri Karpo Mountain is important contributor to global mean sea level rise, and it change runoff distribution, increase risk of glacial lake outburst floods (GLOFs). Because of their difficult accessibility and high labor costs, the knowledge of glaciological parameters of glaciers in the Kangri Karpo Mountain is still limited. This study presents glacier elevation changes in the Kangri Karpo Mountain, by utilizing geodetic methods based on digital elevation models (DEM) derived from Topographic Maps (1980), the Shuttle Radar Topography Mission (SRTM) DEM (2000), and TerraSAR-X/TanDEM-X (2014). Glacier area and length changes were derived from Topographical Maps and Landsat TM/ETM+/OLI images between 1980 and 2015. Our results show that the Kangri Karpo Mountain contains 1166 glaciers, with an area of 2048.50 ± 48.65 km2 in 2015. Ice cover in the Kangri Karpo Mountain diminished by 679.51 ± 59.49 km2 (24.9 % ± 2.2 %) or 0.71 % ± 0.06 % a-1 from 1980–2015, however, with nine glaciers in advance from 1980–2015. Glaciers with area of 788.28 km2 in the region, as derived from DEM differencing, have experienced a mean mass deficit of 0.46 ± 0.08 m w.e. a-1 from 1980–2014. These glaciers showed slight accelerated shrinkage and significant accelerated mass loss during 2000–2015 compared to that during 1980–2000, which is consistent with the tendency of climate warming.

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 Recent glacier mass balance and area changes in the Kangri Karpo Mountains from DEMs and glacier inventories

2018 ◽  
Vol 12 (1) ◽  
pp. 103-121 ◽  
Author(s):  
Kunpeng Wu ◽  
Shiyin Liu ◽  
Zongli Jiang ◽  
Junli Xu ◽  
Junfeng Wei ◽  
...  
Keyword(s):  
Mass Loss ◽  
Shuttle Radar Topography Mission ◽  
Glacier Mass Balance ◽  
The Tibetan Plateau ◽  
Run Off ◽  
Outburst Floods ◽  
Digital Elevation ◽  
Elevation Changes ◽  
Length Changes ◽  
Global Mean Sea Level

Abstract. Due to the influence of the Indian monsoon, the Kangri Karpo Mountains in the south-east of the Tibetan Plateau is in the most humid and one of the most important and concentrated regions containing maritime (temperate) glaciers. Glacier mass loss in the Kangri Karpo is an important contributor to global mean sea level rise, and changes run-off distribution, increasing the risk of glacial-lake outburst floods (GLOFs). Because of its inaccessibility and high labour costs, information about the Kangri Karpo glaciers is still limited. Using geodetic methods based on digital elevation models (DEMs) derived from 1980 topographic maps from the Shuttle Radar Topography Mission (SRTM) (2000) and from TerraSAR-X/TanDEM-X (2014), this study has determined glacier elevation changes. Glacier area and length changes between 1980 and 2015 were derived from topographical maps and Landsat TM/ETM+/OLI images. Results show that the Kangri Karpo contained 1166 glaciers with an area of 2048.50 ± 48.65 km2 in 2015. Ice cover diminished by 679.51 ± 59.49 km2 (24.9 ± 2.2 %) or 0.71 ± 0.06 % a−1 from 1980 to 2015, although nine glaciers advanced. A glacierized area of 788.28 km2, derived from DEM differencing, experienced a mean mass loss of 0.46 ± 0.08 m w.e. a−1 from 1980 to 2014. Shrinkage and mass loss accelerated significantly from 2000 to 2015 compared to 1980–2000, consistent with a warming climate.

scholarly journals Glacier changes and surges over Xinqingfeng and Malan Ice Caps in the inner Tibetan Plateau since 1970 derived from Remote Sensing Data

2019 ◽  
Author(s):  
Zhen Zhang ◽  
Shiyin Liu ◽  
Zongli Jiang ◽  
Donghui Shangguan ◽  
Junfeng Wei ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Loss ◽  
Accumulation Rate ◽  
Remote Sensing Data ◽  
Landsat 8 ◽  
Glacier Area ◽  
Mean Velocity ◽  
Ice Caps ◽  
Total Mass Loss ◽  
Year 2000

Abstract. The inner Tibetan Plateau region is a glacierised area with heterogeneous variations. However, the detailed glacier area and mass changes in this region prior to the year 2000 are scarce, and there are limited processes available to understand this heterogeneity. In this paper, we present an integrated view of the glacier area and its mass changes for Mt. Xinqingfeng and Mt. Malan of the inner Tibetan Plateau as derived from topographic maps, Landsat, ASTER, SRTM DEM, and TerraSAR-X/TanDEM-X for the period of 1970–2012 and 1970–2018, respectively. Our results show that the glaciers experienced weak shrinkage in area by 0.09 ± 0.03 % from 1970 to 2018, but there was a median mass loss at a rate of 0.22 ± 0.17 m w.e. a−1 and 0.29 ± 0.17 m w.e. a−1 during 1999–2012 in Mt. Xinqingfeng and Mt. Malan respectively. The glaciers of Mt. Malan have had a lower total mass loss of 0.19 ± 0.14 m w.e. a−1 during 1970–1999. The mean velocity of the glaciers during 2013–2018 was 0.16 m d−1, as demonstrated from the Global Land Ice Velocity Extraction from Landsat 8 (GoLIVE). The Monuomaha Glacier and Zu Glacier together with another 5 glaciers displayed the surging or advancing characteristics during the observation period. These glaciers showed have a long active period of time and comparatively low velocities, which suggests that thermal controls are important for the surge initiation and recession. The ablation area or accumulation area exhibited small slopes with velocities that were too slow to remain in balance with the accumulation rate; thus, they required surging to transport mass from the reservoir area down the glacier tongue.

Fullerene-like Nanoparticles of WS2 as a Promising Protection from Erosive Wear of Gun Bore Nozzles

2020 ◽  
Vol 16 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Narimane Rezgui ◽  
Danica Simić ◽  
Choayb Boulahbal ◽  
Dejan Micković
Keyword(s):  
Mass Loss ◽  
Solid Lubricant ◽  
Erosive Wear ◽  
Mechanical Resistance ◽  
Protective Function ◽  
Protective Layers ◽  
Total Mass Loss ◽  
Mass Losses ◽  
Before And After ◽  
Tube Life

Background: Erosive wear causes increase in the bore diameter of firearms barrels and nozzles. Most responsible factors for this erosion are friction and heat generated during the shot. Protection from erosive wear is very important for gun tube life cycle, and various protection methods are used: adding phlegmatizers in gunpowder composition or applying protective layers on the gun bore inner surface. Objective: In this research, a possibility is examined to protect the surface of a nozzle exposed to gunpowder erosion applying a layer of tungsten disulfide fullerene-like nanoparticles, IF-WS2, known as outstanding solid lubricant of a great mechanical resistance. Methods: Nanoparticles on the nozzle surface before and after the gunfire tests were observed using scanning electron microscopy/energy dispersive X-ray spectroscopy. Gunfire tests were performed on designed erosion device. Temperatures in the defined position near the affected surface were measured with thermocouples and compared for the nozzles with and without nanoprotection, as well as the nozzle mass loss after each round. Results: For the sample with IF-WS2 lower temperatures after firing and lower mass losses were observed. Mass loss after first round was 25.6% lower for the sample with protective nanoparticles layer, and the total mass loss was about 5% lower after five rounds. After the first round the nozzle without IF-WS2 was heated up to a temperature which was for 150.8°C higher than the nozzle with IF-WS2. Conclusion: Protective function of IF-WS2 is the most pronounced for the first round. The observed results encourage its further application in firearms gun bores protection.

New methodical approaches to mapping of geosystems (by the example of Baikalian Siberia’s geosystems)

2018 ◽  
Vol 937 (7) ◽  
pp. 23-34 ◽  
Author(s):  
I.N. Vladimirov
Keyword(s):  
Global Climate ◽  
Remote Sensing Data ◽  
Field Research ◽  
Scientific Basis ◽  
Nature Management ◽  
Climate Data ◽  
Structural Dynamic ◽  
Digital Elevation ◽  
North Asia ◽  
Elevation Model

The article considers a new approach to landscape mapping based on the synthesis of remote sensing data of high and medium spatial resolution, a digital elevation model, maps of various thematic contents, a set of global climate data, and materials of field research. The map of the Baikalian’s Siberia geosystems is based on the principles of the multistage regional-typological and structural-dynamic classification of geosystems proposed by Academician V.B. Sochava. The structure of the geosystems of the Baikalian Siberia is characterized by great complexity, both in the set of natural complexes and in the degree of their contrast. The regional classification range covers the geosystems inherent in different subcontinents of Asia and reflects their interpenetration, being a unique landscape-situational example of Siberian nature within North Asia. The map of the geosystems of the Baikalian Siberia reflects the main structural and dynamic diversity of geosystems in the region in the systems of their geographic and genetic spatial structures. These landscape cartographic studies fit into a single system of geographic forecasting and create a new fundamental scientific basis for developing recommendations for optimizing nature management in the Baikal region within the framework of implementing state environmental policy.

scholarly journals High Mountain Asian glacier response to climate revealed by multi-temporal satellite observations since the 1960s

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Atanu Bhattacharya ◽  
Tobias Bolch ◽  
Kriti Mukherjee ◽  
Owen King ◽  
Brian Menounos ◽  
...  
Keyword(s):  
Mass Loss ◽  
River Flow ◽  
Tien Shan ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Temperature And Precipitation ◽  
Multi Temporal ◽  
The 1960S ◽  
Northern Tien Shan

AbstractKnowledge about the long-term response of High Mountain Asian glaciers to climatic variations is paramount because of their important role in sustaining Asian river flow. Here, a satellite-based time series of glacier mass balance for seven climatically different regions across High Mountain Asia since the 1960s shows that glacier mass loss rates have persistently increased at most sites. Regional glacier mass budgets ranged from −0.40 ± 0.07 m w.e.a−1 in Central and Northern Tien Shan to −0.06 ± 0.07 m w.e.a−1 in Eastern Pamir, with considerable temporal and spatial variability. Highest rates of mass loss occurred in Central Himalaya and Northern Tien Shan after 2015 and even in regions where glaciers were previously in balance with climate, such as Eastern Pamir, mass losses prevailed in recent years. An increase in summer temperature explains the long-term trend in mass loss and now appears to drive mass loss even in regions formerly sensitive to both temperature and precipitation.

Leaching of Am-241 from a Radioactive Waste Glass Corroded in the Presence of Stainless Steel Corrosion Products and/or Bentonite

1987 ◽  
Vol 112 ◽  
Author(s):  
Masaki Tsukamoto ◽  
Inga-Kari Björner ◽  
Hilbert Christensen ◽  
Hans-Peter Hermansson ◽  
Lars Werme
Keyword(s):  
Stainless Steel ◽  
Radioactive Waste ◽  
Mass Loss ◽  
Total Mass ◽  
Corrosion Behaviour ◽  
Steel Corrosion ◽  
Waste Glass ◽  
Corrosion Products ◽  
Total Mass Loss ◽  
Elemental Mass

AbstractThe release of Am-241 during corrosion of the radioactive waste glass, JSS-A, has been studied in the presence of corrosion products and/or uncom-pacted bentonite. The corrosion behaviour of Am-241 has been analyzed using gamma spectrometry. Adsorption of Am-241 on bentonite is observed in all cases. The contents of Am-241 in centrifuged leachates are in most cases less than 1/100 of total values. The normalized elemental mass loss of Am increases initially with corrosion time, and the values in the presence of bentonite and corrosion products are larger than those in the presence of bentonite alone. This tendency is in agreement with results previously found for other elements. The release of Am is low, only about 10–20 % of the corresponding total mass loss.

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