Total Glacier Area Research Articles

Influence of topography on glacier changes in the central Himalaya, India

Assessing the impact of topography on glacier changes is vital because, while climate is the driving force behind these changes, the topography may control their heterogeneity. Present study provides a detailed insight into varied responses of 18 glaciers (1994–2015), spread over the central Himalaya (CH), and systematically explores the influence of topographic factors on changing glacier parameters using satellite remote sensing data (Landsat TM/ETM+/OLI, Cartosat-1 PAN, Resoursesat-2 LISS-4, SRTM digital elevation model) and limited field observations. Results show that the total glaciated area decreased from 313.34±7.95km2 in 1994 to 306.36±8.04km2 in 2015 whereas retreat rates varied from 4.75±2.25 to 28.25±2.25ma−1 during this period. The total debris-covered area also increased from 86.56±1.29 to 97.99±1.75km2 and the average snowline altitude upshifted by 67m during 1994–2015. Various topographic factors analyzed here include: glacier area, length, compactness ratio, altitude, slope, aspect, hypsometry, area accumulation ratio and snout characteristics. Multivariate statistical analysis demonstrates that compactness ratio, glacier size, altitude range and mean slope strongly influence the area loss. Whereas glacier length, mean slope, compactness and altitude range influence the retreat rates. Cumulative influence of these factors was assessed using a novel approach which uses ordinal scale relative weighting-rating technique to compute a Topographic Influence Index (TII). Breaks in the frequency of TII values were used for categorizing the glaciers into three groups that experienced different degrees of topographic influence on area loss and retreat namely, modest, moderate and strong. It is observed that, out of 18 glaciers, 5 had modest, 8 had moderate and 5 glaciers had strong influence of topography on area loss. Whereas, 6, 8 and 4 glaciers experienced modest, moderate and strong influence of topography on retreat, respectively. Further, we found that ~78% and ~61% glaciers in case of area loss and retreat, respectively, are also the ones which exhibit higher glacier wastage. This indicates that the observed heterogeneity in the response of studied glaciers is probably topographically induced.

Changes of glaciers and glacial lakes implying corridor-barrier effects and climate change in the Hengduan Shan, southeastern Tibetan Plateau

ABSTRACTChanges of glaciers and glacial lakes and their causes were examined in the Hengduan Shan from 1990 to 2014, based on Landsat TM/ETM+/OLI images. A total glacier area of 1298.8 ± 62.1 km2 and glacial lake area of 255.8 ± 31.6 km were inventoried in 2014. The area of glaciers declined at an average rate of −0.40 ± 0.26% a−1, while glacial lakes expanded at average rate of +0.12 ± 0.03% a−1 over the past 24 years. These changes probably resulted from an observable temperature increase and slight precipitation increase. A ‘corridor-barrier’ effect formed by the longitudinal range–gorge terrain may have had major impacts on the distributions and changes of glaciers and glacial lakes. The Ningjing-Yunling Shan, where glaciers and glacial lakes are sparsely distributed, are an important geographic transition line in the Hengduan Shan because of the barrier effect of the mountain ranges against moisture from the southwest. In contrast, between the south and north, there were small differences with respect to the distributions and changes of glaciers and glacial lakes, owing to a north–south corridor effect for water and heat transport and diffusion through the longitudinal gorges in the Hengduan Shan.

‘Little Ice Age’ glacier extent and subsequent retreat in Svalbard archipelago

The influence of the ‘Little Ice Age’ (LIA) on the glaciers of Svalbard has been well documented for a long time. This paper presents new data on the LIA maximum glacier extent and retreat by aerial photo interpretation and Geographic Information Systems (GIS) tools. We also make cartography where all results are shown in greater detail. During the LIA maximum, we find that the glacier area of Svalbard was 38,871 km2, and since then, the total glacier area loss in the archipelago has been 5096 km2 (13.1%). The total current glaciated area from the late 2000s is 33,775 km2. Since the LIA, the glaciers in the main islands of the archipelago have retreated by 12.8% in Spitsbergen, 13.4% in Nordaustlandet, and 16.7% in Barentsøya and Edgeøya. The analysis of the LIA maximum glacier extent in the different major drainage basins shows important differences; about 100 years ago, some glacier basins were more than 19% larger in the western and central regions of Spitsbergen, or even more than 23% larger in southern Nordaustlandet, while other small basins found in the northeast of this island were barely 1% larger. The greatest retreats are found in the tidewater glaciers, more variable and responsive to the water temperature changes, water dynamics, and bathymetry. In addition, the advances at some of these glaciers may correspond with surges, which means that the rapid retreats are caused by the post-surging phases as well as climate. The conclusions of this research point out an important ice loss in all of Svalbard since the LIA and the high vulnerability of this Arctic archipelago to global warming.

Early 21st century glacier thickness changes in the Central Tien Shan

Although studies based on satellite gravimetry (2003−2010) and laser altimetry (2003–2009) measurements have achieved region-wide glacier mass change for the Tien Shan, the dynamic process of glacier yet to be closely monitored and understood so that its impact can be assessed accurately. In this study, we investigated region-wide glacier thickness change in the Central Tien Shan (CTS) during 2000–2012 by differencing the Shuttle Radar Topographic Mission (SRTM) digital elevation model (DEM) with a newly constructed DEM from 27 TanDEM-X images. For a total glacier area of 7239.8±527.2km2, an average glacier thickness change rate of −0.24±0.22m/a was derived. This result agrees well with the result based on satellite laser altimetry measurements reported earlier (−0.31±0.41m/a). With temporal synchronization, a fine spatial resolution and wide coverage, our measurements are able to reveal abundant glacier change features and dependencies in the CTS. Firstly, the lower mountains have seen a more severe glacier decline, and the glaciers facing the prevailing wind (westerlies) have experienced a greater decline because of the stronger evaporation. Furthermore, those glaciers lying along the extremely high Meridian mountain range have obviously gained mass in their upper reaches, because the air current from the west is blocked and lifted by the Meridian mountain range. Secondly, for the entire glacier body, the theoretical hyperbolic dependence between debris thickness and ice decline was very difficult to establish. Some huge glaciers covered by heavy debris have still experienced a severe decline. However, even though the heavy debris did not prevent the ablation, its attenuating effects were considerable. Thirdly, for the glaciers that surged before 2000, the mass gain in the restoring zones has not been enough to cover the mass loss in ablation zones. Some large glaciers surged again during 2000–2012; however, with much lower magnitudes than in previous surges. In general, the surge glaciers have experienced a greater decline than the non-surge glaciers. Fourthly, due to the ice front calving and subglacial thermal erosion, glaciers connected to proglacial lakes have receded and thinned much more rapidly than the land-terminated glaciers. Overall, the glaciers in the CTS are more stable than those in other parts of the Tien Shan. However, the glacier state there is still alarming. A moderate average thinning rate was derived because the drastic thinning in the ablation zones was balanced by the slight thinning in the broad accumulation zones.

Comparison of Glacier Mass Balance Data in the Tien Shan and Pamir, Central Asia

ABSTRACTGlacier coverage and behavior are heterogeneous across Tien Shan and Pamir due to a climate gradient from west to east. Regional glacier mass balance data have previously been calculated using GRACE and hydrological models with differing results. In this study, in situ mass balance data of glaciers in the Tien Shan and Pamir, measured by the glaciological method between 2004 and 2012, are spatially extrapolated to the total glacier area by arithmetic averaging using (1) unfiltered balance data, and (2) a smoothing filter to the data in a way similar to that done for GRACE data. GRACE and the in situ data are the only methods that measure mass variations directly. A comparison of the extrapolated unfiltered and filtered in situ data is made with the difference between GRACE and the total water storage of the hydrological model Water Global Assessment and Prognosis Global Hydrology Model that represents glacier mass balance. The annual comparison between the extrapolated in situ and GRACE-related data does not fit very well, but the comparison of mass change rates shows quite good agreement. In comparison with GRACE-related results from the literature, the extrapolation of the unfiltered in situ glacier mass data performs best, especially in the Tien Shan.

Glacial Geomorphology of Mt. Munkh Saridag in the Khuvsgul Mountain Range, Northern Mongolia

This study reconstructs palaeoglacial extent in the Khuvsgul Mountain Range in northern Mongolia based on the mapping of glacial landforms of Mt. Munkh Saridag. For the accurate reconstruction of palaeoglaciations in the Khuvsgul Mountain Range, glacial landforms including glacial valleys, glacial cirques, end moraines, medial moraines, marginal moraines and glacial lineations were mapped at a scale of 1:100.000 for Mt. Munkh Saridag. Mapping was conducted using Google Earth, 30 m resolution ASTER DEM data and 30 m resolution Landsat 5TM satellite imagery. This mapping revealed abundant glacial erosional and depositional landforms in the Khuvsgul Mountain Range, in particular, large end moraine complexes mark palaeoglacial advances in the mountain valleys of Mt. Munkh Saridag. Results indicate that Mt. Munkh Saridag, the center of Khuvsgul Mountain Range, had lost 42.6% of its total glacier area between 1970 (900 m²) and 2007 (384 m²) when the equilibrium-line altitudes (ELAs) of the glaciers were retreated by 47 m and 80 m on north and south aspects, respectively. The outer limits of these glacial landforms show development of small ice caps on peaks and ice fields in valleys of Mt. Munkh Saridag where their maximum glaciation was reconstructed to have covered 186 km². The spatial analyses show the dynamic change of the modern glaciers in Mt. Munkh Saridag, and how this depends on topographical elements of elevation and aspects, durations of solar radiation and vulnerability to the solar insolation. This study demonstrates that spatial analysis of the glacial landforms is crucial for reviewing the extent of palaeoglaciers that could be detailed with dates in further work.

Changes in the ablation zones of glaciers in the western Himalaya and the Karakoram between 1972 and 2015

Observed estimates of changes in the Himalayan and Karakoram glaciers remain ambiguous because of limited knowledge regarding complex glacier behaviour, low quality of remote sensing data, and sparse ground-based monitoring. Remote sensing has indicated anomalous behaviour of glaciers in the Karakoram during the past two decades, attracting scientists' attention to the region. In this context, this study has made detailed estimates of changes in thickness and area of two glaciers (the Sachen in the western Himalaya and the Burche in the Karakoram) to facilitate understanding of recent glacier changes and their potential impacts on water resources. This study used several datasets, including Landsat, the Shuttle Radar Topographic Mission (SRTM), the Ice, Cloud and Land Elevation Satellite (ICESat), and differential Global Positioning System (dGPS) in-situ measurements, from the period 1972 through 2015. The extent of debris cover increased significantly between 1972 and 2014, while the total glacierized area decreased slightly. Further, our study estimated thickness changes after removing recognizable biases and seasonal variations, computed through comparisons of ICESat data with dGPS. A thinning trend occurred between 2000 and 2015, suggesting that the glaciers in the western part of the Karakoram and Himalaya regions have not recently gained mass. This study also found non-uniform variations within different zones of the glaciers. Avalanches have fed most of the Karakoram glaciers, providing spatially heterogeneous thickness changes. The frequency of observations, data quality, acquisition time, and local weather affect our observations of temporal changes. Careful assessment of regularly acquired remote-sensing and ground-based observations should reduce uncertainty regarding estimates of glacier changes for management of water resources and associated hazards.

Stikine Icefield Mass Loss between 2000 and 2013/2014

We calculate thinning rates ($\frac{dh}{dt}$) at the 5,800 km\textsuperscript{2} Stikine Icefield of southeast Alaska from stacked digital elevation models (DEMs) acquired between 2000 and 2013/2014, and glacier velocities between 1985 and 2014 from feature tracking on optical image pairs. We find a mass change rate of -3.3 $\pm$ 1.1 Gt yr\textsuperscript{-1} between 2000 and 2014, equivalent to an area-averaged elevation change rate of -0.57 $\pm$ 0.18 m w.e. yr\textsuperscript{-1}. In 2014, land-terminating glaciers are 50\% of the Stikine Icefield's glaciated area and contribute -0.9 $\pm$ 0.4 Gt yr\textsuperscript{-1} of mass change (27\% of the total), while marine-terminating glaciers are only 30\% of the total glaciated area, but contribute -1.5 $\pm$ 0.3 Gt yr\textsuperscript{-1} (or 45\% of total mass change, with the remaining mass loss from lacustrine-terminating glaciers). We estimate the frontal ablation flux between 2000 and 2014 at the four largest marine-terminating glaciers on the Stikine Icefield (covering 90 to 95\% of the marine-terminating glaciated area) using our glacier velocities and maps of fjord bathymetry to estimate terminus cross sections and glacier thicknesses. The combined 2014 frontal ablation flux of these four glaciers is 1.18 $\pm$ 0.14 Gt yr\textsuperscript{-1}, which may account for the difference in average mass loss between marine- and land-terminating glaciers on the Stikine Icefield. The Stikine and adjacent Juneau Icefields have very different mass loss contributions from marine-terminating glaciers (45\% vs. effectively 0\%), but both have area-averaged elevation change rates that are less negative than Alaska-wide estimates, which is surprising for these southernmost icefields in Alaska.

Little Ice Age glacier extension and retreat in Spitsbergen Island (High Arctic, Svalbard Archipelago)

The influence of the Little Ice Age on the glaciers of Spitsbergen has been well documented by many investigations since long time. This paper studies, measures and presents new data on the Little Ice Age maximum glacier extension and retreat by aerial photo interpretation and Geographic Information Systems (GIS) tools use. It also elaborates cartography where all the results are expressed in greater detail. During the LIA maximum the Island of Spitsbergen was covered with a 7.34% more of ice than today. After the Little Ice Age, the total glacier area loss was 13.84%, which means a total of 2769.8 Km2 over the 20,008.7 Km2 of the total glaciated in the current context. The analysis of the maximum Little Ice Age glacier extension in the major drainage basins brings important differences among them; hardly 100 years ago some basin drainage increased the glacier area more than 24% (in the western and central region of Spitsbergen), while others less than 5% (in the northeast region of the Island). The greatest retreats are found in the tidewater glaciers that extend into the sea, which we explain due to different factors: their glacier front beds are found below the sea level, the intense ablation of the calving process, the fact that their tidewater fronts are thin and temperate (which make them more dynamic and very sensitive to climate fluctuations), and that the advances of these glaciers may correspond with surges, which means that the rapid retreats are motivated by the post-surging phases as well. The conclusions of the present research point out a very important ice loss in the whole Island since the Little Ice Age, and the high vulnerability of this Arctic Archipelago to global warming.

Accelerating retreat and high-elevation thinning of glaciers in central Spitsbergen

Abstract. Svalbard is a heavily glacier-covered archipelago in the Arctic. Dickson Land (DL), in the central part of the largest island, Spitsbergen, is relatively arid and, as a result, glaciers there are relatively small and restricted mostly to valleys and cirques. This study presents a comprehensive analysis of glacier changes in DL based on inventories compiled from topographic maps and digital elevation models for the Little Ice Age (LIA) maximum, the 1960s, 1990, and 2009/2011. Total glacier area has decreased by ∼ 38 % since the LIA maximum, and front retreat increased over the study period. Recently, most of the local glaciers have been consistently thinning in all elevation bands, in contrast to larger Svalbard ice masses which remain closer to balance. The mean 1990–2009/2011 geodetic mass balance of glaciers in DL is among the most negative from the Svalbard regional means known from the literature.

Modeling debris-covered glaciers: response to steady debris deposition

Abstract. Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedbacks in the debris–glacier–climate system, we developed a 2-D long-valley numerical glacier model that includes englacial and supraglacial debris advection. We ran 120 simulations on a linear bed profile in which a hypothetical steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier terminus. Our model and parameter selections can produce 2-fold increases in glacier length. Debris flux onto the glacier and the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibrium-line altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Debris deposited near the equilibrium-line altitude re-emerges high in the ablation zone and therefore impacts melt rate over a greater fraction of the glacier surface. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to initial debris-free glaciers. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). Our simulations reproduce the "general trends" between debris cover, AARs, and glacier surface velocity patterns from modern debris-covered glaciers. We provide a quantitative, theoretical foundation to interpret the effect of debris cover on the moraine record, and to assess the effects of climate change on debris-covered glaciers.

Accelerated glacier shrinkage in the Ak-Shyirak massif, Inner Tien Shan, during 2003–2013

The observed increase in summer temperatures and the related glacier downwasting has led to a noticeable decrease of frozen water resources in Central Asia, with possible future impacts on the economy of all downstream countries in the region. Glaciers in the Ak-Shyirak massif, located in the Inner Tien Shan, are not only affected by climate change, but also impacted by the open pit gold mining of the Kumtor Gold Company. In this study, glacier inventories referring to the years 2003 and 2013 were created for the Ak-Shyirak massif based on satellite imagery. The 193 glaciers had a total area of 351.2±5.6km2 in 2013. Compared to 2003, the total glacier area decreased by 5.9±3.4%. During 2003–2013, the shrinkage rate of Ak-Shyirak glaciers was twice than that in 1977–2003 and similar to shrinkage rates in Tien Shan frontier ranges. We assessed glacier volume in 2013 using volume–area (VA) scaling and GlabTop modelling approaches. Resulting values for the whole massif differ strongly, the VA scaling derived volume is 30.0–26.4km3 whereas the GlabTop derived volume accounts for 18.8–13.2km3. Ice losses obtained from both approaches were compared to geodetically-derived volume change. VA scaling underestimates ice losses between 1943 and 2003 whereas GlabTop reveals a good match for eight glaciers for the period 2003–2012. In comparison to radio-echo soundings from three glaciers, the GlabTop model reveals a systematic underestimation of glacier thickness with a mean deviation of 16%. GlabTop tends to significantly underestimate ice thickness in accumulation areas, but tends to overestimate ice thickness in the lowermost parts of glacier snouts. Direct technogenic impact is responsible for about 7% of area and 5% of mass loss for glaciers in the Ak-Shyirak massif during 2003–2013. Therefore the increase of summer temperature seems to be the main driver of accelerated glacier shrinkage in the area.

Glacier changes in the eastern Nyainqêntanglha Range of Tibetan Plateau from 1975 to 2013

Maritime-type glaciers in the eastern Nyainqentanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold (TM3/TM5 for the Landsat TM /ETM+ and TM4/TM6 for Landsat OLI) to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data (1975) and Landsat TM, ETM+ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change (APAC) was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10a and 15.4 mm/10a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.

Glacier change over the last century, Caucasus Mountains, Georgia, observed from old topographical maps, Landsat and ASTER satellite imagery

Abstract. Changes in the area and number of glaciers in the Georgian Caucasus Mountains were examined over the last century, by comparing recent Landsat and ASTER images (2014) with older topographical maps (1911, 1960) along with middle and high mountain meteorological stations data. Total glacier area decreased by 8.1 ± 1.8 % (0.2 ± 0.04 % yr−1) or by 49.9 ± 10.6 km2 from 613.6 ± 9.8 km2 to 563.7 ± 11.3 km2 during 1911–1960, while the number of glaciers increased from 515 to 786. During 1960–2014, the total ice area decreased by 36.9 ± 2.2 % (0.7 ± 0.04 % yr−1) or by 207.9 ± 9.8 km2 from 563.7 ± 11.3 km2 to 355.8 ± 8.3 km2, while glacier numbers decreased from 786 to 637. In total, the area of Georgia glaciers reduced by 42.0 ± 2.0 % (0.4 ± 0.02 % yr−1) between 1911 and 2014. The eastern Caucasus section had the highest retreat rate of 67.3 ± 2.0 % (0.7 ± 0.02 % yr−1) over this period, while the central part of Georgian Caucasus had the lowest, 34.6 ± 1.8 % (0.3 ± 0.01 % yr−1), with the western Caucasus intermediate at 42.8 ± 2.7 % (0.4 ± 0.03 % yr−1).

A satellite-derived glacier inventory for North Asia

AbstractThis study outlines a consistent methodology for identifying glacier surfaces from Landsat 5, 7 and 8 imagery that is applied to map all mainland North Asian glaciers, providing the first methodologically consistent and complete glacier inventory for the region ~2010. We identify 5065 glaciers covering a planimetric area of 2326 ± 186 km2, most of which is located in the Altai mountain subregion. The total glacier count is 15% higher, but the total glacier area is 32 ±11.6% lower, than the estimated glacier coverage provided in version 4.0 of the Randolph Glacier Inventory. We investigate the distribution of glacier size within North Asia and find that the majority of glaciers (82%) are smaller than 0.5 km2 but only account for a third of the total glacier area, with the largest 1 % (60 glaciers ≥ 5 km2 ) accounting for 28% of the total area. We present hypsometric characterizations of North Asian glaciers, largely substantiating existing findings that glaciers in this region are dominated by cold, relatively dry conditions. We provide a detailed assessment of errors and determine the uncertainty in our area estimate to be ±8.0%, with snow-cover uncertainty the largest contributing factor. Based on this assessment, the new glacier inventory presented here is more complete and of higher quality than other currently available data sources.

Glacial evolution in the Ayilariju region, Western Himalaya, China: 1980–2011

Changes in glacial geometries (extent and surface elevations) in the Ayilariju region of Western Himalaya, China, were investigated using topographical maps and data from the Landsat Thematic Mapper/Enhanced Thematic Mapper Plus, the Satellite Pour l’Observation de la Terre (SPOT4), the Shuttle Radar Topography Mission 4.1 digital elevation model, and geographical information system techniques. The results showed that the total glaciated area decreased from 190.37 to 162.52 km2 (14.6 % of the 1980 glaciated area) from 1980 to 2011. Furthermore, total glacial mass loss of studied region was estimated to be 2.570 ± 0.327 km3 between 1980 and 2000. Further investigation on meteorological data indicated that increases of temperature and total radiation were the primary causes of accelerated glacial melting. Reduced wind speed and slight decreases in precipitation triggered by weakening of the South Asian summer monsoon due to warming, may also have contributed to glacial shrinkage. The rate of glacial retreat in the studied region is lower than that in the southern Himalayan region, but larger than that in the Karakoram, primarily because Ayilariju glaciers were located on the margin of the Indian monsoon dominated region.

Changing regimes of gangotri and surrounding glaciers: A case study of Garhwal Himalaya, India

In the present study, 16 selected glaciers including Gangotri and surrounding covering an area of 2982.14sqkm, Garhwal Himalaya (Uttrakhand) India were mapped and their boundaries were delineated using the Landsat MSS (3rd November, 1976), TM (16th October, 1990), ETM+(18th October, 1999 and) and OLI-TIRS (29th Oct., 2013) ) and ASTER images. In this study a total of 101 glacial lakes are identified in 2013 while the number of identified glacial lakes was 69 and 128 in 1990 and 1999. The valley of Gangotri glacier and Satopanth glacier show huge increase in number and area of glacial lakes especially supraglacial lakes. Several morphometric parameters like length, width, total area, perimeter, accumulation area, ablation area, area accumulation ratio (AAR), thickness etc. were estimated for detailed morphometric analysis among the mapped glaciers. The mapping of selected 16 glaciers during the period 1972–2013 reveals that the glacier covered area reduced from 409.08 to 377.83sqkm observing approx. 7.63% deglaciation in the Gangotri and surrounding area. Gangotri glacier shown a net loss of 4.68% area during 1972–2013 while it shows a net gain of 1.32% area during 1999–2013. Advancement in the total glacier area was also recorded during 1979–1999. A higher rate of retreat of the some of the glaciers was observed during 1989–2006 as compared to the retreat during 1972–1989. The average elevation of the ablation zone of Gangotri glacier showed an upward shift from 3944m (1972) to 4033m (2013) which may be a consequence of a shift in Equilibrium Line Altitude (ELA) reflecting imbalance. In this study it is estimated that the Gangotri glacier was retreated 1.60km between 1972–2013. During the period of 1972–2013, it was observed that maximum retreat among selected 16 glacier were mainly Arwa, Raktavaran, Panpatia, Chaturangi, Satopant glaciers (9.47km, 6.43km, 3.87 and 3.04km respectively).

Glacier changes since the early 1960s, eastern Pamir, China

Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region. In the last 50 years, these glaciers have shrunk and lost ice mass due to climate change. In order to understand recent glacier dynamics in the region, a new inventory was compiled from Landsat TM/ETM+ images acquired in 2009, free of clouds and with minimal snow cover on the glacierized mountains. The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs. Total glacier area decreased by 10.8%±1.1%, mainly attributed to an increase in air temperature, although precipitation, glacier size and topographic features also combined to affect the general shrinkage of the glaciers. The 19.3–21.4 km3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.

Glaciers of Avacha group of volcanoes in Neoholocene

The study of moraines at the Avacha volcano group revealed that glaciers changes at all volcanoes within the group happened almost synchronously. Glacial deposits could be grouped into three generations, corresponding to three periods of glacier fluctuations in Neoholocene. The largest glaciation within the group occurred ~2000 years ago. Fragments of moraine, corresponding to that period were found only in the moraine complex of the Ditmar Glacier which was 15% larger then today at that time. The most of moraines at the Avacha volcano group were formed during the Little Ice Age, which in the studied region continued up to the first decades of XX centuries. The maximal advance of glaciers probably happened in XVII century. The moraine corresponding to that period was found at the Kozelsky Glacier valley. At present time the total area of glaciers which moraines were described and dated approaches 21.46 km2. The area of reconstructed moraines corresponding to the Little Ice Age is estimated to be 2.79 km2, therefore at that period the total glaciation area reaches 24,25 км2 exceeding the present area by 13%. It could be claimed that in general during the time past the Little Ice Age the glaciation nature and glacier types did not change sufficiently. The rate of glacier degradation at various parts of the group is different and depends mainly on exposition. At the valleys of four glaciers we found moraines formed in the middle of XX century. They may appear in 1941–1952 when the unfavorable weather conditions leaded to stable negative anomalies in accumulation have happened.

Inventory of glaciers in mongolia, derived from landsat imagery from 1989 to 2011

Glaciers in the Altai Mountains of Mongolia provide an estimated 11% of the total water resources within the country. Yet, their number and area in inconsistent. Using satellite imagery acquired from Landsat 4, 5, and 7, and SRTM digital elevation model (DEM) data, we present here an intuitive, robust, and inexpensive methodology to map the exposed ice of glaciers in the Altai Mountains for the period 1989 to 2011. The total glacierized area was 515 km2 in 1989/1991, 428 km2 in 1998/2001, and 372 km2 in 2010/2011; it decreased by 17% from 1989/1991 to 1998/2001, 13% from 1998/2001 to 2010/2011, and 28% for the entire period 1989/1991 to 2010/2011. In analyzing a sub‐sample of 260 glaciers, 6% advanced, 11% were stable, and 83% receded from 1989 to 2011. The glacier dataset is available to the public free of charge at the Global Land Ice Measurements from Space (GLIMS) website.