scholarly journals Longbasaba Glacier recession and contribution to its proglacial lake volume between 1988 and 2018

2021 ◽  
pp. 1-12
Author(s):  
Junfeng Wei ◽  
Shiyin Liu ◽  
Xin Wang ◽  
Yong Zhang ◽  
Zongli Jiang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Total Mass ◽  
Water Volume ◽  
Total Mass Loss ◽  
Lake Volume ◽  
Glacier Recession ◽  
Proglacial Lakes ◽  
Proglacial Lake ◽  
Near Future ◽  
The Himalaya

Abstract During the last few decades, the lake-terminating glaciers in the Himalaya have receded faster than the land-terminating glaciers as proglacial lakes have exacerbated the mass loss of their host glaciers. Monitoring the impacts of glacier recession and dynamics on lake extent and water volume provides an approach to assess the mass interplay between glaciers and proglacial lakes. We describe the recession of Longbasaba Glacier and estimate the mass wastage and its contribution to the water volume of its proglacial lake. The results show that the glacier area has decreased by 3% during 1988–2018, with a more variable recession prior to 2008 than in the last decade. Longbasaba Lake has expanded by 164% in area and 237% in water volume, primarily as a result of meltwater inflow produced from surface lowering of the glacier. Over the periods 1988–2000 and 2000–18, the mass loss contributed by glacier thinning has decreased from 81 to 61% of the total mass loss, accompanied by a nearly doubled contribution from terminus retreat. With the current rate of retreat, Longbasaba glacier is expected to terminate in its proglacial lake for another four decades. The hazard risk of this lake is expected to continue to increase in the near future because of the projected continued glacier mass loss and related lake expansion.

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.

Dose-Rate Dependence of Radiation Damage in Polymers

1998 ◽  
Vol 4 (S2) ◽  
pp. 800-801
Author(s):  
R.F. Egerton ◽  
I. Rauf
Keyword(s):  
Energy Loss ◽  
Mass Loss ◽  
Dose Rate ◽  
Radiation Damage ◽  
Total Mass ◽  
Room Temperature ◽  
Low Loss ◽  
Total Mass Loss ◽  
Diffraction Patterns ◽  
Accumulated Dose

Three aspects of radiation damage are of concern to electron microscopists: changes in crystallographic or molecular structure, mass loss and change in chemical composition. Structural change can be monitored from the fading of diffraction patterns or from loss of fine structure in an energy-loss spectrum. Total mass loss, in the form of a reduction in inelastic-scattering power, can be observed from the low-loss spectrum. Mass loss can also be monitored from energy-loss ionization edges, with the advantage that the loss of particular elements can be studied separately. It is possible to assign a characteristic dose De for the disappearance of a particular element.At room temperature, the amount of damage usually depends on the accumulated dose (exposure) but not on the dose rate (current density). However, cooling the specimen tends to reduce mass loss, probably because of the reduced diffusion coefficients.

scholarly journals Wintertime storage of water in buried supraglacial lakes across the Greenland Ice Sheet

2014 ◽  
Vol 8 (4) ◽  
pp. 3999-4031 ◽  
Author(s):  
L. S. Koenig ◽  
D. J. Lampkin ◽  
L. N. Montgomery ◽  
S. L. Hamilton ◽  
J. B. Turrin ◽  
...  
Keyword(s):  
Mass Loss ◽  
Total Mass ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Subsurface Water ◽  
Blue Color ◽  
Total Mass Loss ◽  
Supraglacial Lakes ◽  
Hydrologic System ◽  
Surface Melt

Abstract. Surface melt over the Greenland Ice Sheet (GrIS) is increasing and estimated to account for half or more of the total mass loss. Little, however, is known about the hydrologic pathways that route surface melt within the ice sheet. In this study, we present over-winter storage of water in buried supraglacial lakes as one hydrologic pathway for surface melt, referred to as buried lakes. Airborne radar echograms are used to detect the buried lakes that are distributed extensively around the margin of the GrIS. The subsurface water can persist through multiple winters and is, on average, ~4.2 + 0.4 m below the surface. The few buried lakes that are visible at the surface of the GrIS have a~unique visible signature associated with a darker blue color where subsurface water is located. The volume of retained water in the buried lakes is likely insignificant compared to the total mass loss from the GrIS but the water will have important implications locally for the development of the englacial hydrologic network, ice temperature profiles and glacial dynamics. The buried lakes represent a small but year-round source of meltwater in the GrIS hydrologic system.

scholarly journals Glacial lakes exacerbate Himalayan glacier mass loss

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Owen King ◽  
Atanu Bhattacharya ◽  
Rakesh Bhambri ◽  
Tobias Bolch
Keyword(s):  
Mass Loss ◽  
Regional Scale ◽  
High Mountain ◽  
Mass Balances ◽  
Glacial Lakes ◽  
Regional Variability ◽  
Glacier Recession ◽  
Minor Portion ◽  
A Minor ◽  
The Himalaya

AbstractHeterogeneous glacier mass loss has occurred across High Mountain Asia on a multi-decadal timescale. Contrasting climatic settings influence glacier behaviour at the regional scale, but high intra-regional variability in mass loss rates points to factors capable of amplifying glacier recession in addition to climatic change along the Himalaya. Here we examine the influence of surface debris cover and glacial lakes on glacier mass loss across the Himalaya since the 1970s. We find no substantial difference in the mass loss of debris-covered and clean-ice glaciers over our study period, but substantially more negative (−0.13 to −0.29 m w.e.a−1) mass balances for lake-terminating glaciers, in comparison to land-terminating glaciers, with the largest differences occurring after 2000. Despite representing a minor portion of the total glacier population (~10%), the recession of lake-terminating glaciers accounted for up to 32% of mass loss in different sub-regions. The continued expansion of established glacial lakes, and the preconditioning of land-terminating glaciers for new lake development increases the likelihood of enhanced ice mass loss from the region in coming decades; a scenario not currently considered in regional ice mass loss projections.

scholarly journals Wintertime storage of water in buried supraglacial lakes across the Greenland Ice Sheet

2015 ◽  
Vol 9 (4) ◽  
pp. 1333-1342 ◽  
Author(s):  
L. S. Koenig ◽  
D. J. Lampkin ◽  
L. N. Montgomery ◽  
S. L. Hamilton ◽  
J. B. Turrin ◽  
...  
Keyword(s):  
Mass Loss ◽  
Total Mass ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Surface Expression ◽  
Subsurface Water ◽  
Blue Color ◽  
Total Mass Loss ◽  
Supraglacial Lakes ◽  
Hydrologic System

Abstract. Increased surface melt over the Greenland Ice Sheet (GrIS) is now estimated to account for half or more of the ice sheet's total mass loss. Here, we show that some meltwater is stored, over winter, in buried supraglacial lakes. We use airborne radar from Operation IceBridge between 2009 and 2012 to detect buried supraglacial lakes, and we find that they were distributed extensively around the GrIS margin through that period. Buried supraglacial lakes can persist through multiple winters and are, on average, ~ 1.9 + 0.2 m below the surface. Most buried supraglacial lakes exist with no surface expression of their occurrence in visible imagery. The few buried supraglacial lakes that do exhibit surface expression have a unique visible signature associated with a darker blue color where subsurface water is located. The volume of retained water in the buried supraglacial lakes is likely insignificant compared to the total mass loss from the GrIS, but the water may have important implications locally for the development of the englacial hydrologic system and ice temperatures. Buried supraglacial lakes represent a small but year-round source of meltwater in the GrIS hydrologic system.

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