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 Multi-decadal mass loss of glaciers in the Everest area (Nepal Himalaya) derived from stereo imagery

2011 ◽  
Vol 5 (2) ◽  
pp. 349-358 ◽  
Author(s):  
T. Bolch ◽  
T. Pieczonka ◽  
D. I. Benn
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Mass Balance ◽  
Aerial Images ◽  
Glacier Mass Balance ◽  
Ice Melt ◽  
Debris Cover ◽  
Stereo Imagery ◽  
Glacier Velocity ◽  
The Himalaya

Abstract. Mass loss of Himalayan glaciers has wide-ranging consequences such as changing runoff distribution, 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. Here, we present a time series of mass changes for ten glaciers covering an area of about 50 km2 south and west of Mt. Everest, Nepal, using stereo Corona spy imagery (years 1962 and 1970), aerial images and recent high resolution satellite data (Cartosat-1). This is the longest time series of mass changes in the Himalaya. We reveal that the glaciers have been significantly losing mass since at least 1970, despite thick debris cover. The specific mass loss for 1970–2007 is 0.32 ± 0.08 m w.e. a−1, however, not higher than the global average. Comparisons of the recent DTMs with earlier time periods indicate an accelerated mass loss. This is, however, hardly statistically significant due to high uncertainty, especially of the lower resolution ASTER DTM. The characteristics of surface lowering can be explained by spatial variations of glacier velocity, the thickness of the debris-cover, and ice melt due to exposed ice cliffs and ponds.

Estimation of multi-period glacier mass balance in southeast Tibet using high-resolution remote sensing observations

2020 ◽  
Author(s):  
Yushan Zhou ◽  
Zhiwei Li ◽  
Xin Li ◽  
Donghai Zheng
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Tibet Plateau ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Southeastern Part ◽  
Glacier Changes ◽  
Southeast Tibet ◽  
Proglacial Lake ◽  
Basal Melting

<p>Glaciers in the southeastern part of the Tibet Plateau (TP) have experienced the most rapid mass loss over the High Mountain Asia. Hence, a multi-period investigation on the mass balance with focus on how glaciers evolve is imperative for better understanding of the glacier dynamics responding to climate change. Taking the Yanong glacier connected with a proglacial lake in the southeast TP as an example, we estimate the glacier mass budget at multiple-year and interannual timescales via reproducing a multiple-period DEM datasets, including KH-9 (1975), SRTM (2000), TanDEM-X (2011<strong>−</strong>2014) and SPOT-7 (2015) DEMs. We also estimate the penetration depths of both X- and C-band radar using Pléiades stereo images and TanDEM-X data , which are found to be 3.2 m and 4.5 m on average in this area. The results show that the Yanong glacier has been subject to an accelerated mass loss over the past four decades (1975<strong>−</strong>2015), and the tendency of surface thinning spread from low altitudes to high altitudes. Specifically, the mass balance of the Yanong glacier changes from <strong>−</strong>0.50 ± 0.13 m w.e./a (1974<strong>−</strong>2000) to <strong>−</strong>0.95 ± 0.13 m w.e./a (2000<strong>−</strong>2012) and to <strong>−</strong>1.02 ± 0.31 m w.e./a (2012<strong>−</strong>2015) at the multi-year timescale. A serious surface subsidence event is noted in areas that are about 2 km away from the glacier fronts after 2012, which are possibly caused by the internal/basal melting or collapsing. After further analyzing the evolution process of the proglacial lake, we found that the continuous disintegration of the glacier fronts may be the main reason for the accelerated mass deficit.</p><p> </p>

scholarly journals Surface velocity fluctuations for Glaciar Universidad, central Chile, between 1967 and 2015

2016 ◽  
Vol 62 (235) ◽  
pp. 847-860 ◽  
Author(s):  
RYAN WILSON ◽  
SEBASTIAN H. MERNILD ◽  
JEPPE K. MALMROS ◽  
CLAUDIO BRAVO ◽  
DANIELA CARRIÓN
Keyword(s):  
Time Series ◽  
Mass Balance ◽  
General Pattern ◽  
Surface Velocity ◽  
Glacier Mass Balance ◽  
Velocity Fluctuations ◽  
The Andes ◽  
Cumulative Change ◽  
Glacier Velocity ◽  
Andes Cordillera

ABSTRACTFor the Andes Cordillera, where observed mass-balance records are sparse, long-term glacier velocity measurements potentially represent a useful tool for assessing glacier health. Utilising manual and automatic feature-tracking techniques applied to Corona, Landsat and ASTER satellite imagery, this paper presents surface velocity fluctuations for Glaciar Universidad between 1967 and 1969, and 1985 and 2015, the longest such time series available for the Andes Cordillera, outside Patagonia. This time series reveals an increase in the surface velocities of the main glacier trunk between 1967 and 1987 (~90%) followed by a deceleration between 1987 and 2015 (~80%), with ice velocities observed between 2014 and 2015 possibly representing a 48 a low. In response to the surface velocity fluctuations, the glacier front advanced between 1985 and 1992 (cumulative change of 137 ± 14 m), and again to a lesser magnitude during the 1996–98 and 2004–08 periods. Although having exhibited possible surge behaviour during the 1940s, the synchrony of the glacier changes presented for Glaciar Universidad with those reported for nearby glaciers, suggests that this glacier is responding to climatic trends. If the above scenario is true, the results indicate a general pattern of increasingly negative glacier mass-balance conditions since the late 1980s.

scholarly journals Debris Emergence Elevations and Glacier Change

2021 ◽  
Vol 9 ◽  
Author(s):  
Joseph M. Shea ◽  
Philip D. A. Kraaijenbrink ◽  
Walter W. Immerzeel ◽  
Fanny Brun
Keyword(s):  
Mass Balance ◽  
Relative Mass ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Optical Remote Sensing ◽  
Velocity Change ◽  
Regional Patterns ◽  
Average Value ◽  
Debris Cover ◽  
Glacier Velocity

Debris-covered glaciers represent potentially significant stores of freshwater in river basins throughout High Mountain Asia (HMA). Direct glacier mass balance measurements are extremely difficult to maintain on debris-covered glaciers, and optical remote sensing techniques to evaluate annual equilibrium line altitudes (ELAs) do not work in regions with summer-accumulation type glaciers. Surface elevation and glacier velocity change have been calculated previously for debris-covered glaciers across the region, but the response of debris cover itself to climate change remains an open question. In this research we propose a new metric, i.e. the debris emergence elevation (ZDE), which can be calculated from a combination of optical and thermal imagery and digital elevation data. We quantify ZDE for 975 debris-covered glaciers in HMA over three compositing periods (1985–1999, 2000–2010, and 2013–2017) and compare ZDE against median glacier elevations, modelled ELAs, and observed rates of both mass change and glacier velocity change. Calculated values of ZDE for individual glaciers are broadly similar to both median glacier elevations and modelled ELAs, but slightly lower than both. Across the HMA region, the average value of ZDE increased by 70 +/− 126 m over the study period, or 2.7 +/− 4.1 m/yr. Increases in ZDE correspond with negative mass balance rates and decreases in glacier velocity, while glaciers and regions that show mass gains and increases in glacier velocity experienced decreases in ZDE. Regional patterns of ZDE, glacier mass balance, and glacier velocities are strongly correlated, which indicates continued overall increases in ZDEE and expansion of debris-covered areas as glaciers continue to lose mass. Our results suggest that ZDE is a useful metric to examine regional debris-covered glacier changes over decadal time scales, and could potentially be used to reconstruct relative mass and ELA changes on debris-covered glaciers using historical imagery or reconstructed debris cover extents.

scholarly journals Geodetic Mass Balance of Haxilegen Glacier No. 51, Eastern Tien Shan, from 1964 to 2018

2022 ◽  
Vol 14 (2) ◽  
pp. 272
Author(s):  
Chunhai Xu ◽  
Zhongqin Li ◽  
Feiteng Wang ◽  
Jianxin Mu ◽  
Xin Zhang
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Laser Scanning ◽  
Mean Value ◽  
Tien Shan ◽  
Glacier Mass Balance ◽  
Topographic Map ◽  
Glacier Surface ◽  
Elevation Changes ◽  
Geodetic Mass Balance

The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive glaciological measurements were implemented from 1999 to 2011 and re-established in 2017. Mass balance of Haxilegen Glacier No. 51 (1999–2015) has recently been reported, but the mass balance record has not extended to the period before 1999. Here, we used a 1:50,000-scale topographic map and long-range terrestrial laser scanning (TLS) data to calculate the area, volume, and mass changes for Haxilegen Glacier No. 51 from 1964 to 2018. Haxilegen Glacier No. 51 lost 0.34 km2 (at a rate of 0.006 km2 a−1 or 0.42% a−1) of its area during the period 1964–2018. The glacier experienced clearly negative surface elevation changes and geodetic mass balance. Thinning occurred almost across the entire glacier surface, with a mean value of −0.43 ± 0.12 m a−1. The calculated average geodetic mass balance was −0.36 ± 0.12 m w.e. a−1. Without considering the error bounds of mass balance estimates, glacier mass loss over the past 50 years was in line with the observed and modeled mass balance (−0.37 ± 0.22 m w.e. a−1) that was published for short time intervals since 1999 but was slightly less negative than glacier mass loss in the entire eastern Tien Shan. Our results indicate that Riegl VZ®-6000 TLS can be widely used for mass balance measurements of unmonitored individual glaciers.

Reconstructing the runoff and mass changes of a maritime Tibetan glacier since 1975

2021 ◽  
Author(s):  
Achille Jouberton ◽  
Thomas E. Shaw ◽  
Evan Miles ◽  
Shaoting Ren ◽  
Wei Yang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Early Stage ◽  
Distributed Model ◽  
Glacier Mass Balance ◽  
The Tibetan Plateau ◽  
Weather Station ◽  
Runoff Simulation

<p>Glaciers are key components of the water towers of Asia and as such are relied upon by large downstream communities for domestic, agricultural and industrial uses. They have experienced considerable shrinking over the last decades, with some of the highest rates of mass loss observed in the south-eastern part of the Tibetan Plateau, where mass loss is also accelerating.  Despite these rapid changes, Tibetan glaciers’ changing role in catchment hydrology remains largely unknown. Parlung No.4 Glacier is considered as a benchmark glacier in this region, since its meteorology, surface energy fluxes and mass-balance have been examined since 2006. It is a maritime glacier with a spring (April-May) accumulation regime , which is followed by a period of ablation during the Indian Summer Monsoon (typically June-September). Here, we conduct a glacio-hydrological study over a period of five decades (1978-2018) using a fully distributed model for glacier mass balance and runoff simulation (TOPKAPI-ETH). We force the model with ERA5-Land and China Meteorological Forcing Dataset (CMFD) climate reanalysis downscaled to a local weather station to reconstruct meteorological time series at an hourly resolution. TOPKAPI-ETH is calibrated and validated with automatic weather station data, discharge measurements, geodetic mass balance, stake measurements and snow cover data from MODIS. We find a very clear acceleration in mass loss from 2000 onwards, which is mostly explained by an increase in temperature. This influence however was initially compensated by an increase in precipitation until the 2000’s, which attenuated the negative trend. Our results also indicate that the increase in the liquid-solid precipitation ratio has reduced the amount of seasonal accumulation, exacerbating annual mass loss. We demonstrate that the southern westerlies and the associated spring precipitation have as much influence on the glacier mass balance and catchment discharge as the Indian Summer Monsoon, by controlling seasonal snowpack development, which simultaneously provides mass to the glacier and protects it from melting in the early stage of the monsoon.</p>

scholarly journals Identifying Dynamically Induced Variability in Glacier Mass-Balance Records

2016 ◽  
Vol 29 (24) ◽  
pp. 8915-8929 ◽  
Author(s):  
John Erich Christian ◽  
Nicholas Siler ◽  
Michelle Koutnik ◽  
Gerard Roe
Keyword(s):  
Time Series ◽  
Mass Balance ◽  
North Pacific ◽  
Large Scale ◽  
Significant Degree ◽  
Temperature Fields ◽  
Dynamical Response ◽  
Glacier Mass Balance ◽  
Local Climate ◽  
Pacific Climate Variability

Abstract Glacier mass balance provides a direct indicator of a glacier’s relationship with local climate, but internally generated variability in atmospheric circulation adds a significant degree of noise to mass-balance time series, making it difficult to correctly identify and interpret trends. This study applies “dynamical adjustment” to seasonal mass-balance records to identify and remove the component of variance in these time series that is associated with large-scale circulation fluctuations (dynamical adjustment refers here to a statistical method and not a glacier’s dynamical response to climate). Mass-balance records are investigated for three glaciers: Wolverine and Gulkana in Alaska and South Cascade in Washington. North Pacific sea level pressure and sea surface temperature fields perform comparably as predictors, each explaining 50%–60% of variance in winter balance and 25%–35% in summer balance for South Cascade and Wolverine Glaciers. Gulkana Glacier, located farther inland, is less closely linked to North Pacific climate variability, with the predictors explaining roughly 30% of variance in winter and summer balance. To investigate the degree to which this variability affects trends, adjusted mass-balance time series are compared to those in the raw data, with common results for all three glaciers; winter balance trends are not significant initially and do not gain robust significance after adjustment despite the large amount of circulation-related variability. However, the raw summer balance data have statistically significant negative trends that remain after dynamical adjustment. This indicates that these trends of increasing ablation in recent decades are not due to circulation anomalies and are consistent with anthropogenic warming.

scholarly journals Region-wide glacier mass balances over the Pamir-Karakoram-Himalaya during 1999–2011

2013 ◽  
Vol 7 (4) ◽  
pp. 1263-1286 ◽  
Author(s):  
J. Gardelle ◽  
E. Berthier ◽  
Y. Arnaud ◽  
A. Kääb
Keyword(s):  
Mass Balance ◽  
Western Himalaya ◽  
Mass Gain ◽  
Shuttle Radar Topography Mission ◽  
Eastern Himalaya ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Grace Data ◽  
Stereo Imagery ◽  
Study Sites

Abstract. The recent evolution of Pamir-Karakoram-Himalaya (PKH) glaciers, widely acknowledged as valuable high-altitude as well as mid-latitude climatic indicators, remains poorly known. To estimate the region-wide glacier mass balance for 9 study sites spread from the Pamir to the Hengduan Shan (eastern Himalaya), we compared the 2000 Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) to recent (2008–2011) DEMs derived from SPOT5 stereo imagery. During the last decade, the region-wide glacier mass balances were contrasted with moderate mass losses in the eastern and central Himalaya (−0.22 ± 0.12 m w.e. yr−1 to −0.33 ± 0.14 m w.e. yr−1) and larger losses in the western Himalaya (−0.45 ± 0.13 m w.e. yr−1). Recently reported slight mass gain or balanced mass budget of glaciers in the central Karakoram is confirmed for a larger area (+0.10 ± 0.16 m w.e. yr−1) and also observed for glaciers in the western Pamir (+0.14 ± 0.13 m w.e. yr−1). Thus, the "Karakoram anomaly" should be renamed the "Pamir-Karakoram anomaly", at least for the last decade. The overall mass balance of PKH glaciers, −0.14 ± 0.08 m w.e. yr−1, is two to three times less negative than the global average for glaciers distinct from the Greenland and Antarctic ice sheets. Together with recent studies using ICESat and GRACE data, DEM differencing confirms a contrasted pattern of glacier mass change in the PKH during the first decade of the 21st century.

scholarly journals Influence of debris cover on terminus retreat and mass changes of Chorabari Glacier, Garhwal region, central Himalaya, India

2013 ◽  
Vol 59 (217) ◽  
pp. 961-971 ◽  
Author(s):  
D.P. Dobhal ◽  
Manish Mehta ◽  
Deepak Srivastava
Keyword(s):  
Mass Balance ◽  
Climate Change Impacts ◽  
Ablation Rate ◽  
Background Information ◽  
Glacier Mass Balance ◽  
Mountain Range ◽  
Central Himalaya ◽  
Himalayan Glaciers ◽  
Debris Cover ◽  
Wide Variability

AbstractRecent studies of Himalayan glacier recession indicate that there is wide variability in terminus retreat rate and mass balance in the different sectors of the mountain range, primarily linked to the topography and climate of the region. Variable retreat rates of glacier termini and inadequate supporting field data (e.g. mass balance, ice thickness, velocity, etc.) in the Himalayan glaciers make it difficult to develop a coherent picture of climate change impacts. In this study, the results of a detailed mapping campaign and ground-based measurements of ablation rate, terminus retreat and ice loss are reported for the period 2003–10. In addition, background information from an old glacier map (Survey of India, 1962) was compiled and terminus recession measurements were carried out from 1990 field photographs of Chorabari Glacier, central Himalaya. Our ablation stake network results suggest that the influence of debris cover is significant for Chorabari Glacier mass balance and terminus retreat. The terminus survey finds that the glacier is retreating, but at a lower rate than many other non-debriscovered glaciers in the region. The recession and ablation data (particularly in the upper ablation area at higher altitudes) suggest that the ice volume loss of the glaciers is of greater magnitude than the slow terminus retreat and, if the process continues, the lowermost part of the glacier may reduce to a quasi-stationary position while significant ice loss continues.

scholarly journals The response of glaciers to climatic persistence

2016 ◽  
Vol 62 (233) ◽  
pp. 440-450 ◽  
Author(s):  
GERARD H. ROE ◽  
MARCIA B. BAKER
Keyword(s):  
Mass Balance ◽  
Statistical Tests ◽  
Glacier Mass Balance ◽  
Climate Variables ◽  
Glacier Changes ◽  
Actual Degree ◽  
Glacier Length ◽  
Temporal Persistence ◽  
Random Fluctuations ◽  
The Impact

AbstractThe attribution of past glacier length fluctuations to changes in climate requires characterizing glacier mass-balance variability. Observational records, which are relatively short, are consistent with random fluctuations uncorrelated in time, plus an anthropogenic trend. However, longer records of other climate variables suggest that, in fact, there is a degree of temporal persistence associated with internal (i.e. unforced) climate variability, and that it varies with location and climate. Therefore, it is likely that persistence does exist for mass balance, but records are too short to confirm its presence, or establish its magnitude, with conventional statistical tests. Extending the previous work, we explore the impact of potential climatic persistence on glacier length fluctuations. We use a numerical model and a newly developed analytical model to establish that persistence, even of a degree so small as to be effectively undetectable in the longest mass-balance records, can significantly enhance the resulting glacier length fluctuations. This has a big impact on glacier-excursion probabilities: what was an extremely unlikely event (<1%) can become virtually certain (>99%), when persistence is incorporated. Since the actual degree of climatic persistence that applies to any given glacier is hard to establish, these results complicate the attribution of past glacier changes.

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