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 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.

scholarly journals Distributed Melt on a Debris-Covered Glacier: Field Observations and Melt Modeling on the Lirung Glacier in the Himalaya

2021 ◽  
Vol 9 ◽  
Author(s):  
Jakob F. Steiner ◽  
Phillip D. A. Kraaijenbrink ◽  
Walter W. Immerzeel
Keyword(s):  
Thermal Conductivity ◽  
Energy Balance ◽  
Mass Loss ◽  
Promising Result ◽  
Monsoon Season ◽  
Energy Balance Model ◽  
Balance Model ◽  
High Temporal Resolution ◽  
High Mountain ◽  
The Himalaya

Debris-covered glaciers, especially in high-mountain Asia, have received increased attention in recent years. So far, few field-based observations of distributed mass loss exist and both the properties of the debris layer as well as the atmospheric drivers of melt below debris remain poorly understood. Using multi-year observations of on-glacier atmospheric data, debris properties and spatial surface elevation changes from repeat flights with an unmanned aerial vehicle (UAV), we quantify the necessary variables to compute melt for the Lirung Glacier in the Himalaya. By applying an energy balance model we reproduce observed mass loss during one monsoon season in 2013. We show that melt is especially sensitive to thermal conductivity and thickness of debris. Our observations show that previously used values in literature for the thermal conductivity through debris are valid but variability in space on a single glacier remains high. We also present a simple melt model, which is calibrated based on the results of energy balance model, that is only dependent on air temperature and debris thickness and is therefore applicable for larger scale studies. This simple melt model reproduces melt under thin debris (<0.5 m) well at an hourly resolution, but fails to represent melt under thicker debris accurately at this high temporal resolution. On the glacier scale and using only off-glacier forcing data we however are able to reproduce the total melt volume of a debris-covered tongue. This is a promising result for catchment scale studies, where quantifying melt from debris covered glaciers remains a challenge.

scholarly journals Mass balance and area changes of glaciers in the Cordillera Real and Tres Cruces, Bolivia, between 2000 and 2016

2019 ◽  
Vol 66 (255) ◽  
pp. 124-136 ◽  
Author(s):  
Thorsten Seehaus ◽  
Philipp Malz ◽  
Christian Sommer ◽  
Alvaro Soruco ◽  
Antoine Rabatel ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Average Rate ◽  
Regional Scale ◽  
Resource Planning ◽  
Mountain Range ◽  
Tropical Andes ◽  
Mass Budget ◽  
Glacier Recession ◽  
Cordillera Real

AbstractClimate change has led to a significant shrinkage of glaciers in the Tropical Andes during the last decades. Recent multi-temporal quantifications of ice mass loss at mountain range to regional scale are missing. However, this is fundamental information for future water resource planning and glacier change projections. In this study, we measure temporally consistent glacier area changes and geodetic mass balances throughout the Bolivian Cordillera Real and Tres Cruces based on multi-sensor remote-sensing data. By analyzing multi-spectral satellite images and interferometric SAR data, a glacier recession of 81 ± 18 km2 (29%; 5.1 ± 1.1 km2 a−1), a geodetic mass balance of −403 ± 78 kg m−2 a−1 and a total ice mass loss of 1.8 ± 0.5 Gt is derived for 2000–2016. In the period 2013–2016, ice mass loss was 21% above the average rate. A retreat rate of 15 ± 5 km2 a−1 and a mass budget of −487 ± 349 kg m−2 a−1 are found in this more recent period. These higher change rates can be attributed to the strong El Niño event in 2015/16. The analyses of individual glacier changes and topographic variables confirmed the dependency of the mass budget and glacier recession on glacier aspect and median elevation.

scholarly journals Glacial lake inventory of Bhutan using ALOS data: methods and preliminary results

2011 ◽  
Vol 52 (58) ◽  
pp. 65-71 ◽  
Author(s):  
Jinro Ukita ◽  
Chiyuki Narama ◽  
Takeo Tadono ◽  
Tsutomu Yamanokuchi ◽  
Nobuhiro Tomiyama ◽  
...  
Keyword(s):  
High Resolution ◽  
Optical Sensors ◽  
Regional Scale ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Surface Models ◽  
Mountain Development ◽  
First Time ◽  
The Himalaya ◽  
Data Processing Methods

AbstarctThe Advanced Land Observing Satellite (ALOS) is relatively new. Its optical sensors are capable of making high-resolution digital surface models (DSMs). For the first time, the task of constructing a regional-scale inventory of glacial lakes based on ALOS data has been undertaken. This study presents the data-processing methods and the results of validation and analysis on the ALOS-based glacial lake inventory of Bhutan in the Himalaya. The analysis based on GPS measurements taken at Metatshota lake in the Mangde Chu sub-basin, one of the glacial lakes assessed as presenting a potential flood danger, shows a validation estimate of 9.5 m for the location of the ALOS-based polygon, with a root mean square of 11.7 m. A comparison with digitized data from the International Centre for Integrated Mountain Development (ICIMOD) shows that positioning and evaluation of terrain changes can be significantly improved using ALOS data. Preliminary analysis of the glacial lakes in four sub-basins, Mo Chu, Pho Chu, Mangde Chu and Dangme Chu, reveals that the frequency distribution of lake sizes biases towards smaller lakes. Glacial lakes 0.01–0.05km2 in area account for ~55% of the total number and occupy 13% of the total area. Together our results demonstrate the usefulness of high-resolution ALOS data with accurate DSMs for studying glacial lakes. High priority must be given to continuously improving and updating the glacial lake inventory with high-resolution satellite data.

scholarly journals Spatial variability in mass change of glaciers in the Everest region, central Himalaya, between 2000 and 2015

2016 ◽  
Author(s):  
Owen King ◽  
Duncan J. Quincey ◽  
Jonathan L. Carrivick ◽  
Ann V. Rowan
Keyword(s):  
Tibetan Plateau ◽  
Mass Loss ◽  
Mass Change ◽  
The Tibetan Plateau ◽  
Glacial Lakes ◽  
Equilibrium Line Altitude ◽  
Glacier Recession ◽  
Himalayan Glaciers ◽  
Distinct Process

Abstract. The mass balance of the majority of Himalayan glaciers is currently negative, and has been for several decades. Region wide averaging of mass change estimates has masked any catchment or glacier scale variability in glacier recession, thus the role of a number of glaciological processes in glacier wastage remains poorly understood. In this study, we quantify surface lowering and mass loss rates for the ablation areas of 32 glaciers in different catchments across the Everest region, and specifically examine the role of glacial lakes in glacier mass change. We then assess how future ice loss is likely to differ depending on glacier hypsometry. Spatially variable ice loss is observed within and between the Dudh Koshi and Tama Koshi catchments and glaciers that flow onto the Tibetan Plateau. Surface lowering rates on glaciers flowing onto the Tibetan Plateau are 54 and 19 % greater than those flowing southward into the Dudh Koshi and Tama Koshi catchments, respectively. Surface lowering rates of up to −3.78 ± 0.26 m a-1 occurred on some lacustrine terminating glaciers, although glaciers with small lakes showed rates of lowering comparable with those that terminate on land. We suggest that such a range reflects glacial lakes at different stages of development, and that rates of mass loss are likely to increase as glacial lakes expand and deep water calving begins to occur. Hypsometric data reveal a coincidence of the altitude of maximum surface lowering and the main glacier hypsometry in the Dudh Koshi catchment, thus a large volume of ice is readily available for melt. Should predicted CMIP5 RCP 4.5 scenario warming (0.9–2.3 °C by 2100) occur in the study area, 19–30, 17–50 and 14–37 % increases in the total glacierised area below the Equilibrium Line Altitude will occur in the Dudh Koshi and Tama Koshi catchments, and on the Tibetan Plateau. Comparison of our data with a conceptual model of Himalayan glacier shrinkage confirms the presence of three distinct process regimes, with all glaciers in our sample now in a state of accelerating mass loss and meltwater storage.

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.

scholarly journals Simulation and Assessment of Future Glacial Lake Outburst Floods in the Poiqu River Basin, Central Himalayas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1376
Author(s):  
Taigang Zhang ◽  
Weicai Wang ◽  
Tanguang Gao ◽  
Baosheng An
Keyword(s):  
River Basin ◽  
Hazard Assessment ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Central Himalayas ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Social And Economic Development ◽  
Glacial Lake Outburst Flood

A glacial lake outburst flood (GLOF) is a typical glacier-related hazard in high mountain regions. In recent decades, glacial lakes in the Himalayas have expanded rapidly due to climate warming and glacial retreat. Some of these lakes are unstable, and may suddenly burst under different triggering factors, thus draining large amounts of water and impacting downstream social and economic development. Glacial lakes in the Poiqu River basin, Central Himalayas, have attracted great attention since GLOFs originating there could have a transboundary impact on both China and Nepal, as occurred during the Cirenmaco GLOF in 1981 and the Gongbatongshaco GLOF in 2016. Based on previous studies of this basin, we selected seven very high-risk moraine-dammed lakes (Gangxico, Galongco, Jialongco, Cirenmaco, Taraco, Beihu, and Cawuqudenco) to simulate GLOF propagation at different drainage percentage scenarios (i.e., 25%, 50%, 75%, and 100%), and to conduct hazard assessment. The results show that, when any glacial lake is drained completely or partly, most of the floods will enter Nepal after raging in China, and will continue to cause damage. In summary, 57.5 km of roads, 754 buildings, 3.3 km2 of farmland, and 25 bridges are at risk of damage due to GLOFs. The potentially inundated area within the Chinese part of the Poiqu River basin exceeds 45 km2. Due to the destructive impacts of GLOFs on downstream areas, appropriate and effective measures should be implemented to adapt to GLOF risk. We finally present a paradigm for conducting hazard assessment and risk management. It uses only freely available data and thus is easy to apply.

scholarly journals Studying the present-day dynamics of Lena delta by space images

2019 ◽  
Vol 46 (6) ◽  
pp. 567-574
Author(s):  
V. I. Kravtsova ◽  
A. N. Inyushin
Keyword(s):  
Marine Terrace ◽  
Southwestern Part ◽  
Space Images ◽  
Delta Coastline ◽  
Local Erosion ◽  
Minor Portion ◽  
Landsat Satellite ◽  
A Minor ◽  
Erosion Material ◽  
Lena Delta

The dynamics of Lena delta coastline since the late XX century up to the present time have been studied using Landsat satellite data. The comparison of different-time images of morphologically different segments of the delta coastline has shown the major portion of the delta to be stable. Minimal changes have been recorded near the mouths of the branches carrying a minor portion of the Lena runoffthe Olenekskaya and Tumatskie. In the eastern part of the delta, near the mouths of copious branches Trofimovskaya and Bykovskaya, no changes have taken place, as well as in its western part, which is represented by a part of abrasion marine terrace embraced by the delta. In the southwestern part, in the Olenek delta, the delta coastline has been eroded with the erosion material transported eastward by along-shore current. Near the mouths of the Tumatskaya branch, the forms of marine accumulation are unstable, and the marine terrace in the northeastern part of the delta shows a minor local erosion. The periods of erosion in different delta areas are not synchronous and the eroded zones are not large in size. No increment in the land, nor shore progradation have been seen.

scholarly journals Longest time series of glacier mass changes in the Himalaya based on stereo imagery

2010 ◽  
Vol 4 (4) ◽  
pp. 2593-2613 ◽  
Author(s):  
T. Bolch ◽  
T. Pieczonka ◽  
D. I. Benn
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Mass Balance ◽  
Aerial Images ◽  
Glacier Mass Balance ◽  
Glacier Changes ◽  
Debris Cover ◽  
Stereo Imagery ◽  
Glacier Velocity ◽  
The Himalaya

Abstract. Mass loss of Himalayan glaciers has wide-ranging consequences such as declining water resources, sea level rise and an increasing risk of glacial lake outburst floods (GLOFs). The assessment of the regional and global impact of glacier changes in the Himalaya is, however, hampered by a lack of mass balance data for most of the range. Multi-temporal digital terrain models (DTMs) allow glacier mass balance to be calculated since the availability of stereo imagery. Here we present the longest time series of mass changes in the Himalaya and show the high value of early stereo spy imagery such as Corona (years 1962 and 1970) aerial images and recent high resolution satellite data (Cartosat-1) to calculate a time series of glacier changes south of Mt. Everest, Nepal. We reveal that the glaciers are significantly losing mass with an increasing rate since at least ~1970, despite thick debris cover. The specific mass loss is 0.32 ± 0.08 m w.e. a−1, however, not higher than the global average. The spatial patterns of surface lowering can be explained by variations in debris-cover thickness, glacier velocity, and ice melt due to exposed ice cliffs and ponds.

scholarly journals Monitoring changes of the Antarctic Ice sheet by GRACE, ICESat and GNSS

2019 ◽  
Vol 49 (4) ◽  
pp. 403-424
Author(s):  
Fang Zou ◽  
Robert Tenzer ◽  
Samurdhika Rathnayake
Keyword(s):  
Mass Loss ◽  
Ice Sheet ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
Ice Volume ◽  
West Antarctic ◽  
Elevation Changes ◽  
A Minor ◽  
The Antarctic

Abstract In this study, we estimate the ice mass changes, the ice elevation changes and the vertical displacements in Antarctica based on analysis of multi-geodetic datasets that involve the satellite gravimetry (GRACE), the satellite altimetry (ICESat) and the global navigation satellite systems (GNSS). According to our estimates, the total mass change of the Antarctic ice sheet from GRACE data is −162.91 Gt/yr over the investigated period between April 2002 and June 2017. This value was obtained after applying the GIA correction of −98.12 Gt/yr derived from the ICE-5G model of the glacial iso-static adjustment. A more detailed analysis of mass balance changes for three individual drainage regions in Antarctica reveal that the mass loss of the West Antarctic ice sheet was at a rate of −143.11 Gt/yr. The mass loss of the Antarctic Peninsula ice sheet was at a rate of −24.31 Gt/yr. The mass of the East Antarctic ice sheet increased at a rate of 5.29 Gt/yr during the investigated period. When integrated over the entire Antarctic ice sheet, average rates of ice elevation changes over the period from March 2003 to October 2009 derived from ICESat data represent the loss of total ice volume of −155.6 km3.The most prominent features in ice volume changes in Antarctica are characterized by a strong dynamic thinning and ice mass loss in the Amundsen Sea Embayment that is part of the West Antarctic ice sheet. In contrast, coastal regions between Dronning Maud Land and Enderby Land exhibit a minor ice increase, while a minor ice mass loss is observed in Wilkes Land. The vertical load displacement rates estimated from GRACE and GPS data relatively closely agree with the GIA model derived based on the ice-load history and the viscosity profile. For most sites, the GRACE signal appears to be in phase and has the same amplitude as that obtained from the GPS vertical motions while other sites exhibit some substantial differences possibly attributed to thermo-elastic deformations associated with surface temperature.

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