Glacier variations in the Himalaya from 1990 to 2015 based on remote sensing

Abstract. The Himalaya is located in the southwest margin of the Tibetan Plateau. The region is of special interest for glacio-climatological research as it is influenced by both the continental climate of Central Asia and The Indian Monsoon system. Despite its large area covered by glaciers, detail glacier inventory data are not yet available for the entire Himalaya. The study presents spatial patterns in glacier area in the entire Himalaya are multiple spatial scales. We combined Landsat TM/ETM+/OLI from 1990 to 2015 and ASTER GEDM (30 m). In the years around 1990 the whole mountain range contained about 12211 glaciers covering an area of 23229.27 km2, while the ice on south slope covered 14451.25 km2. Glaciers are mainly distributed in the western of the Himalaya with an area of 11551.69 km2 and the minimum is the eastern. The elevation of glacier mainly distributed at 4,800∼6,200 m a.s.l. with an area percent of approximately 84 % in 1990. The largest number and ice cover of glaciers is hanging glacier and valley glacier, respectively. The number of debris-covered glaciers is relatively small, whereas covers an area of about 44.21 % in 1990. The glacier decreased by 10.99 % and this recession has accelerated from 1990 to 2015. The average annual shrinkage rate of the glaciers on the north slope (0.54 % a−1) is greater than that on the south slope (0.38 % a−1). Glacier decreased in the debris-covered glaciers and debris-free glaciers, and the area loss for the first is about 15.56 % and 5.22 % for the latter during 1990–2015, which showed that the moraine in the Himalaya can inhibit the ablation of glaciers to some extent.

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Orogenic Segmentation and Its Role in Himalayan Mountain Building

Frontiers in Earth Science ◽

10.3389/feart.2021.641666 ◽

2021 ◽

Vol 9 ◽

Author(s):

Mary Hubbard ◽

Malay Mukul ◽

Ananta Prasad Gajurel ◽

Abhijit Ghosh ◽

Vinee Srivastava ◽

...

Keyword(s):

Continental Collision ◽

Large Contribution ◽

The Tibetan Plateau ◽

Thrust Belt ◽

The North ◽

Mountain Front ◽

Mountain Belts ◽

Basement Structures ◽

Lateral Variations ◽

The Himalaya

The continental collision process has made a large contribution to continental growth and reconfiguration of cratons throughout Earth history. Many of the mountain belts present today are the product of continental collision such as the Appalachians, the Alps, the Cordillera, the Himalaya, the Zagros, and the Papuan Fold and Thrust Belt. Though collisional mountain belts are generally elongate and laterally continuous, close inspection reveals disruptions and variations in thrust geometry and kinematics along the strike of the range. These lateral variations typically coincide with cross structures and have been documented in thrust fault systems with a variety of geometries and kinematic interpretations. In the Himalaya, cross faults provide segment boundaries that, in some cases separate zones of differing thrust geometry and may even localize microseismicity or limit areas of active seismicity on adjacent thrust systems. By compiling data on structural segmentation along the length of the Himalayan range, we find lateral variations at all levels within the Himalaya. Along the Gish fault of the eastern Indian Himalaya, there is evidence in the foreland for changes in thrust-belt geometry across the fault. The Gish, the Ganga, and the Yamuna faults all mark boundaries of salients and recesses at the mountain front. The Benkar fault in the Greater Himalayan sequence of eastern Nepal exhibits a brittle-ductile style of deformation with fabric that crosscuts the older thrust-sense foliation. Microseismicity data from several regions in Nepal shows linear, northeast-striking clusters of epicenters sub-parallel to cross faults. The map pattern of aftershock data from the 2015 Nepal earthquakes has an abrupt northeast-trending termination on its eastern side suggesting the presence of a structure of that orientation that limited slip. The orientations of the recognized cross faults and seismic patterns also align with the extensional zones to the north on the Tibetan Plateau and the Indian basement structures to the south. Results from multiple studies are consistent with a link between cross faults and either of these structural trends to the north or south and suggest that cross faults may play a role in segmenting deformation style and seismic activity along the length of the Himalaya.

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Colliding Continents

10.1093/oso/9780199653003.001.0001 ◽

2013 ◽

Cited By ~ 4

Author(s):

Mike Searle

Keyword(s):

Indian Plate ◽

Mountain Range ◽

Polar Regions ◽

Geological Evidence ◽

North West ◽

Ice Cap ◽

The North ◽

West Himalaya ◽

Tectonically Active ◽

The Himalaya

The Himalaya is the greatest mountain range on Earth: the highest, longest, youngest, the most tectonically active, and the most spectacular of all. Unimaginable geological forces created these spectacular peaks. Indeed, the crash of the Indian plate into Asia is the biggest known collision in geological history, giving birth to the Himalaya and Karakoram, one of the most remote and savage places on Earth. In this beautifully illustrated book, featuring spectacular color photographs throughout, one of the most experienced field geologists of our time presents a rich account of the geological forces that were involved in creating these monumental ranges. Over three decades, Mike Searle has transformed our understanding of this vast region. To gather his vital geological evidence, he has had to deploy his superb skills as a mountaineer, spending weeks at time in remote and dangerous locations. Searle weaves his own first-hand tales of discovery with an engaging explanation of the processes that formed these impressive peaks. His narrative roughly follows his career, from his early studies in the north west Himalaya of Ladakh, Zanskar and Kashmir, through several expeditions to the Karakoram ranges (including climbs on K2, Masherbrum, and the Trango Towers, and the crossing of Snow Lake, the world's largest ice cap outside polar regions), to his later explorations around Everest, Makalu, Sikkim and in Tibet and South East Asia. The book offers a fascinating first-hand account of a major geologist at work-the arduous labor, the eureka moments, and the days of sheer beauty, such as his trek to Kathmandu, over seven days through magnificent rhododendron forests ablaze in pinks, reds and white and through patches of bamboo jungle with hanging mosses. Filled with satellite images, aerial views, and the author's own photographs of expeditions, Colliding Continents offers a vivid account of the origins and present state of the greatest mountain range on Earth.

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What is driving India-Asia convergence?

10.5194/egusphere-egu21-3615 ◽

2021 ◽

Author(s):

Santanu Bose ◽

Wouter P Schellart ◽

Vincent Strak ◽

João C. Duarte ◽

Zhihao Chen

Keyword(s):

Subduction Zones ◽

Boundary Migration ◽

Physical Models ◽

Plate Motion ◽

Indian Plate ◽

Mountain Range ◽

Complete Disappearance ◽

The Tibetan Plateau ◽

Main Driver ◽

The Himalaya

The Himalaya and the Tibetan plateau, the highest mountain range on Earth, have been growing continuously for the last 55 Myrs since India collided with Eurasia. The forces driving this protracted mountain building process are still not fully understood, and continue to puzzle Earth Scientists. Although it is now well accepted that subduction zones are the main driver for plate motion, plate boundary migration, and mantle flow in the asthenosphere, their role in driving Indian indentation into the Asian landmass has never been tested with geodynamic models. This study uses four-dimensional geodynamic physical models to test the role of lateral subduction zones in driving the India-Asia collision. The objective of our study is to investigate if the slab pull force of the Sunda and Makran slabs have any role to play in the dynamics of the ongoing India-Asia convergence, particularly after the complete disappearance of the Tethyan slab, which was primarily steering the northward travel of the Indian plate since late Jurassic. To address this issue, we performed three experiments by varying the size and configuration of the subducting plate in the initial model setup. &#160;Our experimental results show that active subduction of the Indo-Australian plate along the Sunda subduction zone is the main driver of the India-Asia convergence, Indian indentation, the growth of the Himalaya-Tibet mountains, and the eastward extrusion of southeast Asia. Our work further suggests that the protracted growth of collisional mountains on Earth requires nearby active subduction zones and, therefore, Himalayan-type orogens may have been rare in the Earth&#8217;s history.

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Frozen Rivers and Fault Lines

Colliding Continents ◽

10.1093/oso/9780199653003.003.0010 ◽

2013 ◽

Author(s):

Mike Searle

Keyword(s):

Western Himalaya ◽

Mountain Range ◽

The Road ◽

North East ◽

The North ◽

Golden Eagles ◽

Trade Route ◽

Winter Time ◽

The Himalaya ◽

North Western

After seven summer field seasons working in the north-western Himalaya in India, I had heard of a winter trade route that must rank as one of the most outlandish journeys in the Himalaya. The largely Buddhist Kingdoms of Ladakh and Zanskar are high, arid, mountainous lands to the north of the Greater Himalayan Range and in the rain shadow of the summer monsoon. Whereas the southern slopes of the Himalaya range from dense sub-tropical jungles and bamboo forests to rhododendron woods and magnificent alpine pastures carpeted in spring flowers, the barren icy lands to the north are the realm of the snow leopard, the yak, and the golden eagles and lammergeier vultures that soar overhead. The Zanskar Valley lies immediately north-east of the 6–7,000-metre-high peaks of the Himalayan crest and has about thirty permanent settlements, including about ten Buddhist monasteries. I had seen the Zanskar Ranges from the summit of White Sail in Kulu and later spent four summer seasons mapping the geology along the main trekking routes. In summer, trekking routes cross the Himalaya westwards to Kashmir, southwards to Himachal Pradesh, and northwards to Leh, the ancient capital of Ladakh. Winter snows close the Zanskar Valley from the outside world for up to six months a year when temperatures plummet to minus 38oC. Central Zanskar is a large blank on the map, virtually inaccessible, with steepsided jagged limestone mountains and deep canyons. The Zanskar River carves a fantastic gorge through this mountain range and for only a few weeks in the middle of winter the river freezes. The Chaddur, the walk along the frozen Zanskar River, takes about ten to twelve days from Zanskar to the Indus Valley and, in winter time, was the only way in or out before the road to Kargil was constructed. I mentioned this winter trek to Ben Stephenson during our summer fieldwork in Kishtwar and he stopped suddenly, turned around, and said ‘Mike we just have to do this trek!’ So the idea of a winter journey into Zanskar was born, and four of us set off from Oxford in January 1995.

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Quantifying the contribution of Tibetan Plateau (TP) uplift and CO2 decrease for late Eocene and present day climate with emphasis on Meridional Ocean Circulation.

10.5194/egusphere-egu2020-14895 ◽

2020 ◽

Author(s):

Gilles Ramstein ◽

Baohuang Su ◽

Dabang Jiang ◽

Ran Zhang ◽

Pierre Sepulchre

Keyword(s):

Tibetan Plateau ◽

Ocean Circulation ◽

Late Eocene ◽

Ocean Dynamics ◽

Mountain Range ◽

The Tibetan Plateau ◽

Mountain Ranges ◽

The North ◽

Low Co2 ◽

Realistic Description

Since late Eocene (40 Ma), atmospheric CO2 drastically decreased from 4 to 1 PAL. &#160;During this period, two major geological events occurred over Asia: the India/Asia collision producing the uplift of large mountain ranges and the shrinkage of the Paratethys (G. Ramstein et al., Nature, 1997; F. Fluteau et la., JGR, 1999). Most modeling studies focused first on the sensitivity of AGCMs to the Tibetan plateau elevation through simple experiments; then new simulations accounting for more realistic description of paleogeographic reconstructions have been published. Indeed, progress has been done concerning both: paratethys evolution (Z. Zhang et al., PAL PAL PAL, 2007), chronology of uplifts of different mountain ranges (R. Zhang et al., JGR, 2017) and large TP northern shift (R. Zhang et al., EPSL, 2018), but again these experiments focused mostly on atmosphere circulation and hydrologic pattern (monsoon evolution) not specifically on their impacts on ocean dynamics.Therefore, this study aims to investigate the role of TP uplift on Northern hemisphere ocean circulation through long runs of coupled ocean atmosphere model to analyze its impact not only on atmosphere but also on ocean dynamics. We provided a series of sensitivity simulations disentangling the two different factors, pCO2 decrease and TP uplift. These simulations allow analyzing the response to TP uplift in a warm high CO2 world as Eocene and in a cold low CO2 world as Quaternary (B. Su et al., CP, 2018).We describe how the TP uplift through changes of atmosphere (surface winds and planetary waves) and hydrology (runoff and precipitation/evaporation patterns) modified the meridional circulation in the North Atlantic and Pacific basins with emphasize on the causes of the two different basins sensitivity to this major mountain range uplift in both contexts.

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Surface composition of debris-covered glaciers across the Himalaya using spectral unmixing and multi-sensor imagery

10.5194/tc-2020-372 ◽

2021 ◽

Author(s):

Adina E. Racoviteanu ◽

Lindsey Nicholson ◽

Neil F. Glasser

Keyword(s):

Surface Composition ◽

Spatial Scales ◽

Spectral Unmixing ◽

Eastern Himalaya ◽

Mountain Range ◽

Dynamic Topography ◽

Glacier Surface ◽

Proper Understanding ◽

Debris Cover ◽

The Himalaya

Abstract. The Hindu-Kush Himalaya mountain range is characterized by highly glacierized, complex, dynamic topography. The ablation area of these glaciers is often covered a highly heterogeneous debris cover mantle comprising ponds, steep and shallow slopes of various aspects, variable debris thickness and exposed ice cliffs. These surface elements are associated with differing ice ablation rates, and understanding the composition of the glacier surface is essential for a proper understanding of glacier hydrology and glacier-related hazards. Here we use high-resolution Pleiades (2 m) and RapidEye imagery (5 m) combined with Landsat Operational Land Imager (OLI) imagery (30 m) to estimate the composition of debris-covered glacier tongues across the Himalaya around the year 2015. We use linear spectral unmixing to map various types of debris, clean ice, supraglacial ponds and vegetation on debris-covered glaciers across the mountain range. We develop the spectral unmixing methods in the Khumbu region of eastern Nepal, and then apply them over the entire Himalaya (a glacier area of 2,254 km2). This allowed us to convert 30 m fractional maps into finer classification maps and to estimate the composition of debris-covered glaciers at various spatial scales. Debris-covered glaciers across the mountain range comprised 2.1 % supraglacial ponds, 12.8 % dark debris, 60.9 % light debris and 4.5 % supra glacial vegetation, with negligible amounts of clean ice and clouds and unclassified areas. Supraglacial ponds were more prevalent in the monsoon-influenced central-eastern Himalaya (up to 4 % of the debris cover area) compared to the monsoon-dry transition zone (only 0.3 %). The automated fractional supraglacial pond maps developed here serve to complement and improve the accuracy of existing regional lake datasets. They also provide a basis for exploring the turbidity of lakes and ponds as indicators of glacier change processes, and to monitor the evolution of ponds in the context of glacial hazards.

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Present and future states of Himalaya and Karakoram glaciers

Annals of Glaciology ◽

10.3189/172756411799096277 ◽

2011 ◽

Vol 52 (59) ◽

pp. 69-73 ◽

Cited By ~ 84

Author(s):

J. Graham Cogley

Keyword(s):

Mass Loss ◽

Total Mass ◽

Average Rate ◽

Public Perceptions ◽

Mountain Range ◽

Scaling Relation ◽

Glacier Inventory ◽

Constant Rate ◽

Mountain Development ◽

The Himalaya

AbstractA complete glacier inventory of the Himalaya and Karakoram (H-K) has been created by merging records from the Chinese Glacier Inventory, several regional inventories produced by the International Centre for Integrated Mountain Development, Kathmandu, Nepal, and partial inventories from the Geological Survey of India. The only remaining gap, the Indian part of Kashmir, has been filled by a reconnaissance inventory based on Soviet military maps at 1 : 200 000 scale representing the late 1970s. It contains records for 3526 glaciers covering 9584 km2. The new H-K inventory contains records and outlines for 20 812 glaciers covering 43 178 km2. The extent of ice in the Karakoram is slightly less than in the Himalaya, but the Karakoram glaciers are on average twice as thick (~160m as against ~80 m). A glacier-by-glacier analysis, relying on estimates of mass balance for the entire mountain range and on an extension of the often-used volume–area scaling relation, suggests that up to about one-fifth of the glaciers present in 1985 may have disappeared already. If mass loss were to remain constant at the average rate for 1975–2008, from 3000 to 13 000 more glaciers might disappear by 2035. If mass loss were to continue to accelerate as inferred for 1985–2008, only a few thousand to a few hundred glaciers might remain in 2035. Total area and total mass would each decrease by about one-half (constant-rate assumption) or three-quarters (constant-trend assumption). These projections, which are uncertain and neglect some possibly important mitigating controls, such as variable extents of debris cover and the feedback due to retreat to higher elevations, demonstrate the need for more complete analyses to inform public perceptions of, and policy decisions relating to, the health of H-K glaciers.

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A glacier inventory for the western Nyainqentanglha Range and the Nam Co Basin, Tibet, and glacier changes 1976–2009

The Cryosphere ◽

10.5194/tc-4-419-2010 ◽

2010 ◽

Vol 4 (3) ◽

pp. 419-433 ◽

Cited By ~ 163

Author(s):

T. Bolch ◽

T. Yao ◽

S. Kang ◽

M. F. Buchroithner ◽

D. Scherer ◽

...

Keyword(s):

Drainage Basin ◽

Mountain Range ◽

The Tibetan Plateau ◽

Nam Co ◽

Change Analysis ◽

Glacier Inventory ◽

Manual Adjustment ◽

Main Driver ◽

Climate Interactions ◽

Lake Nam Co

Abstract. The western Nyainqentanglha Range is located in the south-eastern centre of the Tibetan Plateau. Its north-western slopes drain into Lake Nam Co. The region is of special interest for glacio-climatological research as it is influenced by both the continental climate of Central Asia and the Indian Monsoon system, and situated at the transition zone between temperate and subcontinental glaciers. A glacier inventory for the whole mountain range was generated for the year around 2001 using automated remote sensing and GIS techniques based on Landsat ETM+ and SRTM3 DEM data. Glacier change analysis was based on data from Hexagon KH-9 and Landsat MSS (both 1976), Metric Camera (1984), and Landsat TM/ETM+ (1991, 2001, 2005, 2009). Manual adjustment was especially necessary for delineating the debris-covered glaciers and the glaciers on the panchromatic Hexagon data. In the years around 2001 the whole mountain range contained about 960 glaciers covering an area of 795.6 ± 22.3 km2 while the ice in the drainage basin of Nam Co covered 198.1 ± 5.6 km2. The median elevation of the glaciers was about 5800 m with the majority terminating around 5600 m. Five glaciers with debris-covered tongues terminated lower than 5200 m. The glacier area decreased by −6.1 ± 3% between 1976 and 2001. This is less than reported in previous studies based on the 1970s topographic maps and Landsat data from 2000. Glaciers continued to shrink during the period 2001–2009. No advancing glaciers were detected. Detailed length measurements for five glaciers indicated a retreat of around 10 m per year (1976–2009). Ice cover is higher south-east of the mountain ridge which reflects the windward direction to the monsoon. The temperature increase during the ablation period was probably the main driver of glacier wastage, but the complex glacier-climate interactions need further investigation.

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A glacier inventory for the western Nyainqentanglha Range and Nam Co Basin, Tibet, and glacier changes 1976–2009

The Cryosphere Discussions ◽

10.5194/tcd-4-429-2010 ◽

2010 ◽

Vol 4 (2) ◽

pp. 429-467 ◽

Cited By ~ 13

Author(s):

T. Bolch ◽

T. Yao ◽

S. Kang ◽

M. F. Buchroithner ◽

D. Scherer ◽

...

Keyword(s):

Drainage Basin ◽

Western Slope ◽

Mountain Range ◽

The Tibetan Plateau ◽

Nam Co ◽

Change Analysis ◽

Glacier Inventory ◽

Manual Adjustment ◽

Lake Nam Co ◽

Year 2000

Abstract. The western Nyainqentanglha Mountain Range is located in the south-eastern centre of the Tibetan Plateau. Its north-western slope drains into Lake Nam Co. The area is of special interest for glacio-climatological research as this region is influenced by both the continental climate of Central Asia and the Indian Monsoon system, and it is situated at the transition zone between temperate and subcontinental glaciers. A glacier inventory for the whole mountain range was generated for the year ~2000 using automated remote sensing and GIS techniques based on Landsat ETM+ and SRTM3 DEM data. The change analysis is based on data from Hexagon KH-9 and Landsat MSS (year 1976), Metric Camera (year 1984), and Landsat TM/ETM+ (1991, 2001, 2005, 2009). Manual adjustment was especially necessary for the panchromatic Hexagon data and for debris-covered glaciers. The whole mountain range contains about 960 glaciers covering an area of 795.6 ± 22.3 km2 while the ice in the drainage basin of Nam Co covers 198.1 ± 5.6 km2. The median elevation of the glaciers is ~5800 m a with the majority terminating around 5600 m. Five glaciers with debris-covered tongues terminate lower than 5200 m. The glacier area decreased between 1976 and 2001 by about 6 ± 3%, which is less than presented in previous studies based on topographic maps from the 1970s and Landsat data from 2000. Glaciers continued to shrink during the period 2001–2009. No advancing glaciers were detected. Detailed length measurements for five glaciers indicate a retreat of the tongues of around 10 m per year (1976–2009) with higher absolute but lower relative values for the larger glaciers.

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Study of water storage variations at the Pantanal wetlands area from GRACE monthly mass grids

Journal of Geodetic Science ◽

10.1515/jogs-2019-0013 ◽

2019 ◽

Vol 9 (1) ◽

pp. 133-143

Author(s):

Ayelen Pereira ◽

Cecilia Cornero ◽

Ana C. O. C. Matos ◽

M. Cristina Pacino ◽

Denizar Blitzkow

Keyword(s):

Water Mass ◽

Spatial Scales ◽

Water Storage ◽

Transport Processes ◽

Satellite Gravity ◽

The North ◽

Paraguay River ◽

Gravity Recovery ◽

Grace Mission ◽

Phase Differences

Abstract The continental water storage is significantly in-fluenced by wetlands, which are highly affected by climate change and anthropogenic influences. The Pantanal, located in the Paraguay river basin, is one of the world’s largest and most important wetlands because of the environmental biodiversity that represents. The satellite gravity mission GRACE (Gravity Recovery And Climate Experiment) provided until 2017 time-variable Earth’s gravity field models that reflected the variations due to mass transport processes-like continental water storage changes-which allowed to study environments such as wetlands, at large spatial scales. The water storage variations for the period 2002-2016, by using monthly land water mass grids of Total Water Storage (TWS) derived from GRACE solutions, were evaluated in the Pantanal area. The capability of the GRACE mission for monitoring this particular environment is analyzed, and the comparison of the water mass changes with rainfall and hydrometric heights data at different stations distributed over the Pantanal region was carried out. Additionally, the correlation between the TWS and river gauge measurements, and the phase differences for these variables, were also evaluated. Results show two distinct zones: high correlations and low phase shifts at the north, and smaller correlation values and consequently significant phase differences towards the south. This situation is mainly related to the hydrogeological domains of the area.

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