Glacier Parameters Research Articles

Updating glacier inventories on the periphery of Antarctica and Greenland using multi-source data

Abstract Melting and calving of glaciers and ice caps in Antarctica and Greenland could potentially contribute significantly to global sea level rise. Updates to existing outlines that provide critical glacier baseline information in both regions could help in the analysis of particular changes in glacier parameters such as area and volume from time-series inventories. Here we synthesize previously established techniques and apply new multi-source datasets to update glacier outlines in selected test areas of Antarctica and Greenland, as well as to reduce uncertainties and errors during the mapping process. The workflow includes mapping glacier boundaries, subdividing glaciers by watersheds and assigning glacier attributes. Complicated glacier scenarios and updating challenges in polar regions are discussed and demonstrated by representative case studies. For the first time in Antarctica, we analyze the effect of terminus types on mapped glacier areas, and in Greenland we compare the differences with glacier mapping results using Landsat OLI and ETM+. With new data sources, the methods described in this study might help to create glacier outlines on a larger scale in Antarctica and Greenland. Although data sources can be substituted, the enormous amount of manual labor required to update glacier inventories remains a significant challenge.

Assessing the state, parameter-interlinkages and dynamic shift of glaciers in the western Himalaya

The present study remotely investigates multiple parameters of 25 well-distributed glaciers in the western Himalaya (WH) for ~1990–2015 period to understand their state. Glacier changes for 1990–2000 (pre-2000) and 2000–2015 (post-2000) were analysed separately to assess the shift in glacier dynamics. Results reveal a clear glacier terminus retreat (13.4 ± 2.1 m/y), deglaciation (0.2 ± 0.1%/y), surface velocity slowdown (21%) and increase in number of glacial lakes (28 to 38) as well their area (5%/y) during 1990–2015. Notably, average terminus retreat and deglaciation rates were reduced post-2000 (retreat: 12.5 ± 3.2 m/y; deglaciation: 0.1 ± 0.1%/y) compared to pre-2000 (retreat: 15.3 ± 6.8 m/y; deglaciation: 0.2 ± 0.2%/y). Further, the average surface velocity was found to be increasing (0.9%/y) over 1990–2000. This can be linked with suggested less negative or slightly balanced condition of the WH glaciers over 1990s by previous studies. Present study also finds low downwasting during pre-2000 (−0.24 ± 0.14 m/y). Post-2000, studied glaciers downwasted (−0.50 ± 0.06 m/y) and slowed down (2%/y) significantly showing a decadal time lag in geometrical adjustment. Supraglacial debris, largely influenced by slope characteristics, increased with a uniform rate of 0.9%/y during pre- and post-2000 periods. Systematic analysis of interlinkages among various glacier parameters reveals a large interdependency. Further, presence of debris cover and pro- and supra-glacial lakes modify the glacier response to a great extent. Overall, the present study shows that (a) studied glaciers were in overall depleting phase over 1990–2015, (b) balanced conditions during 1990s prevailed over the studied glaciers, followed by accelerated mass wastage, (c) topography and local surface conditions introduce the intraregional heterogeneity in glacier response to climate.

A Wireless Real-Time Continuous Monitoring System for the Internal Movements of Mountain Glaciers Using Sensor Networks

With the escalation of global warming, the shrinkage of mountain glaciers has accelerated globally, the water volume from glaciers has changed, and relative disasters have increased in intensity and frequency (for example, ice avalanches, surging glaciers, and glacial lake outburst floods). However, the wireless monitoring of glacial movements cannot currently achieve omnidirectional, high-precision, real-time results, since there are some technical bottlenecks. Based on wireless networks and sensor application technologies, this study designed a wireless monitoring system for measuring the internal parameters of mountain glaciers, such as temperature, pressure, humidity, and power voltage, and for wirelessly transmitting real-time measurement data. The system consists of two parts, with a glacier internal monitoring unit as one part and a glacier surface base station as the second part. The former wirelessly transmits the monitoring data to the latter, and the latter processes the received data and then uploads the data to a cloud data platform via 4G or satellite signals. The wireless system can avoid cable constraints and transmission failures due to breaking cables. The system can provide more accurate field-monitoring data for simulating glacier movements and further offers an early warning system for glacial disasters.

Glacier mass balance estimation in Garhwal Himalaya using improved accumulation area ratio method.

Water requirements of the mountain communities living in the Himalaya are supported by snow and glacier melt. The availability of water from the source depends on numerous climatic and glacier parameters. One key parameter is mass balance, which helps to assess the glacier health and future water availability. We have used the improved accumulation area ratio (IAAR) method to estimate mass balance in Alaknanda and Bhagirathi basins, constituting 1055 glaciers covering ~1609 km2. The mean Equilibrium Line Altitude (ELA) of the Alaknanda and Bhagirathi basins are estimated as 6147 ± 130 and 5985 ± 130m.a.s.l, respectively. The mass balance is estimated using the accumulation area ratio (AAR)-mass balance relationship. The mean specific mass balance of the Alaknanda and Bhagirathi for 2001-2013 is estimated as -1.1 ± 0.03m.w.e.a-1 and -1.01 ± 0.07m.w.e.a-1, respectively. Total mass loss from the study area is calculated as ~21.4 ± 1.1Gt during this period. The loss of glaciers in the mountain area will increase the vulnerability of communities living in the region. It suggests a need for better adaptation strategies to improve the resilience of high mountain communities.

Effect of topography on the changes of Urumqi Glacier No. 1 in the Chinese Tianshan Mountains

Topography plays an important role in determining the glacier changes. However, topography has often been oversimplified in the studies of the glacier changes. No systematic studies have been conducted to evaluate the relationship between the glacier changes and topographic features. The present study provided a detailed insight into the changes in the two branches (east branch and west branch) of Urumqi Glacier No. 1 in the Chinese Tianshan Mountains since 1993 and systematically discussed the effect of topography on the glacier parameters. This study analyzed comprehensive recently observed data (from 1992/1993 to 2018/2019), including mass balance, ice thickness, surface elevation, ice velocity, terminus, and area, and then determined the differences in the changes of the two branches and explored the effect of topography on the glacier changes. We also applied a topographic solar radiation model to analyze the influence of topography on the incoming shortwave radiation (SWin) across the entire glacier, focusing on the difference in the SWin between the two branches. The glacier mass balance of the east branch was more negative than that of the west branch from 1992/1993 to 2018/2019, and this was mainly attributed to the lower average altitude of the east branch. Compared with the west branch, the decrease rate of the ice velocity was lower in the east branch owing to its relatively increased slope. The narrow shape of the west branch and its southeast aspect in the earlier period resulted in a larger glacier terminus retreat of the west branch. The spatial variability of the SWin across the glacier surface became much larger as altitude increased. The SWin received by the east branch was slightly larger than that received by the west branch, and the northern aspect could receive more SWin, leading to glacier melting. In the future, the difference of the glacier changes between the two branches will continue to exist due to their topographic differences. This work is fundamental to understanding how topographic features affect the glacier changes, and provides information for building different types of relationship between the glacier area and ice volume to promote further studies on the basin-scale glacier classification.

Stagnation of the Pensilungpa glacier, western Himalaya, India: causes and implications

AbstractThis study investigates stagnation conditions of the Pensilungpa glacier, western Himalaya. Multiple glacier parameters (length, area, debris extent and thickness, snowline altitude (SLA), velocity, downwasting and ice cliffs) were studied using field measurements (2016–18), high-resolution imagery from GoogleEarth (2013–17) and spaceborne Landsat, ASTER and SRTM data (1993–2017) to comprehend the glacier's current state. Results show a moderate decrease in length (6.62 ± 2.11 m a−1) and area (0.11 ± 0.03% a−1), a marked increase in SLA (~6 m a−1) and debris cover (2.86 ± 0.29% a−1) and a slowdown of ~50% during 1993–2016. Notable thinning of −0.88 ± 0.04 m a−1 was observed between 2000 and 2017 showing a similar trend as field measurements during 2016–17 (−0.88 m) and 2017–18 (−1.54 m). Further, results reveal a stagnation of the lower ablation zone (LAZ). Less mass supply and heterogeneous debris growth (6.67 ± 0.41% a−1) over the previous decade resulted in slowdown, margin insulation and slope-inversion, leading to stagnation. Stagnation of LAZ caused bulging in the dynamic upper ablation zone and favored the development of supraglacial ponds and ice cliffs. Ice cliffs have grown significantly (48% in number; 41% in area during 2013–17) and their back-wasting now dominates the ablation process.

Temporal fluctuations and frontal changes of Miyar, Takdung and Uldhampu glaciers, Miyar Valley, Himachal Pradesh, India

Glaciers are one of the key indicators of present and past climatic variations, which responses in the form of retreat or advancement. The frontal characteristics of glaciers constitute the important aspect of glaciological studies and the data obtained gives overall pictures about behaviour of glacier and effect of climate. Due to limitation of satellite data and difficulty in demarcation of actual glacier termini on satellite images, the ground-based monitoring of glaciers fronts and their comparative study with past satellite images were carried out on three glaciers viz. Miyar, Takdung and Uldhampu glaciers, situated in Miyar basin, Lahaul & Spiti district of Himachal Pradesh. This paper presents recessional parameters of glaciers based on field survey and historical satellite images. The studies indicate that the snout of Miyar, Takdung and Uldhampu glaciers have retreated by 1205 m (1962–2017), 270 m (1989–2017) and 130 m (1989–2017) by vacating an area of 0.76, 0.063 and 0.035 square kilometre respectively. Climatic data from 1989–2002 was utilized to correlate recessional trend of all studied glaciers, the precipitation and temperature data supports the given retreat trend by rise in average temperature and lowering precipitation values over data range.

Knud Rasmussen Glacier Status Analysis Based on Historical Data and Moving Detection Using RPAS

This article discusses partial results of an international scientific expedition to Greenland that researched the geography, geodesy, botany, and glaciology of the area. The results here focus on the photogrammetrical results obtained with the eBee drone in the eastern part of Greenland at the front of the Knud Rasmussen Glacier and the use of archive image data for monitoring the condition of this glacier. In these short-term visits to the site, the possibility of using a drone is discussed and the results show not only the flow speed of the glacier but also the shape and structure from a height of up to 200 m. From two overflights near the glacier front at different times, it was possible to obtain the speed of the glacier flow and the distribution of velocities in the glacier stream. The technology uses a comparison of two point clouds derived from a set of aerial photos taken with the eBee drone, and calculating the M3C2 (Multiscale Model-to-Model Cloud Comparison) distances with CloudCompare software. The results correlate with other measurement methods like accurate and long-term measurement with Global Navigation Satellite System (GNSS), satellite radar, or ground geodetical technology. The resulting speed from the drone data reached in the middle part of the glacier, was approximately 12–15m per day. The second part of the paper focuses on the analysis of modern satellite images of the Knud Rasmussen Glacier from Google Earth (Landsat series 1984–2016) and Sentinel 2a, and a comparison with historical aerial images from 1932 to 1933. Historical images were processed photogrammetrically into a three-dimensional (3D) model. Finally, orthogonalized image data from three systems (drone photos, historical aerial photos, and satellite data) were compared in the ArcGIS software. This allows us to analyze glacier changes over time in the time span from 1932 to 2020, with the caveat that from 1933 to 1983 we did not have data at our disposal. The result shows that more significant changes in the area of this glacier occurred after 2011. The main aim of this article is to research the use of photogrammetric methods for monitoring the condition and parameters of glaciers based on non-traditional technology, such as drones or new processing of historical photos.

Моніторинг зміни площі льодовиків, розташованих на островах Галіндез, Вінтер та Скуа (Аргентинські острови, Західна Антарктида)

Due to global warming, the glaciers and ice systems of Antarctica and the Antarctic Peninsula have been significantly changing in shape and size in recent decades. Therefore, to control, forecast and prevent such processes, it is necessary to constantly monitor and analyse changes in the basic parameters of glaciers and ice systems. This paper proposes a study of changes in the area of ice caps located on the Galindez, Winter and Skua islands (Argentine Islands, West Antarctica). The study is based on the integration of different spatio-temporal datasets into a single system for retrospective geographical monitoring of changes in the area of Galindez, Winter and Skua islands ice caps. The system for integrating space-time datasets is the UTM coordinate system (zone 20, South). Using transformed archival cartographic materials, as well as recently obtained orthophotos, the boundaries of the glaciers in different periods of research were digitized. Based on the identified boundaries, the significance of changes in the area of island glaciers, as well as the rate of their change during 1935–2019, were determined. Based on the integration of different spatio-temporal datasets into a single system, retrospective-geographical monitoring of changes in icecaps area during 1935–2019 was performed. The ice caps were found to be experiencing systematic decrease in area with average linear rate of decrease from –0.30%/year to –0.37%/year. A detailed analysis of all integrated spatio-temporal data sets including determination of the cause of changes in the area of the Galindez, Winter and Skua islands' ice caps is a promising topic for further research.

Temporal inventory of glaciers in the Suru sub-basin, western Himalaya: impacts of regional climate variability

Abstract. The importance of updated knowledge about the glacier extent and characteristics in the Himalaya cannot be overemphasized. Availability of precise glacier inventories in the latitudinally diverse western Himalayan region is particularly crucial. In this study we have created an inventory of the Suru sub-basin in the western Himalaya for the year 2017 using Landsat Operational Land Imager (OLI) data. Changes in glacier parameters have also been monitored from 1971 to 2017 using temporal satellite remote-sensing data and limited field observations. Inventory data show that the sub-basin has 252 glaciers covering 11 % of the basin, having an average slope of 25±6∘ (standard deviations have been italicized throughout the text) and dominantly north orientation. The average snow line altitude (SLA) of the basin is 5011±54 m a.s.l. with smaller (47 %) and cleaner (43 %) glaciers occupying the bulk area. Long-term climate data (1901–2017) show an increase in the mean annual temperature (Tmax⁡ and Tmin⁡) of 0.77 ∘C (0.25 and 1.3 ∘C) in the sub-basin, driving the overall glacier variability in the region. Temporal analysis reveals a glacier shrinkage of ∼6±0.02 %, an average retreat rate of 4.3±1.02 m a−1, debris increase of 62 % and a 22±60 m SLA increase in the past 46 years. This confirms their transitional response between the Karakoram and the Greater Himalayan Range (GHR) glaciers. Besides, glaciers in the sub-basin occupy two major ranges, the GHR and Ladakh Range (LR), and experience local climate variability, with the GHR glaciers exhibiting a warmer and wetter climate as compared to the LR glaciers. This variability manifests itself in the varied response of GHR and LR glaciers. While the GHR glaciers exhibit an overall rise in SLA (GHR: 49±69 m; LR: decrease of 18±50 m), the LR glaciers have deglaciated more (LR: 7 %; GHR: 6 %) with an enhanced accumulation of debris cover (LR: 73 %; GHR: 59 %). Inferences from this study reveal prevalence of glacier disintegration and overall degeneration, transition of clean ice to partially debris-covered glaciers, local climate variability and non-climatic (topographic and morphometric)-factor-induced heterogeneity in glacier response as the major processes operating in this region. The Shukla et al. (2019) dataset is accessible at https://doi.org/10.1594/PANGAEA.904131.

Formation of Isotope Parameters (δD, δ18O, and d) of Glaciers and Water Runoff from Severny Island of the Novaya Zemlya Archipelago

Isotope studies (δD and δ18O) were performed for the glaciers of Severny Island (Novaya Zemlya Archipelago). The studied glaciers were characterized by narrow range-of δD and δ18O values (from –15.4 to –17.6 ‰ and from –110.9 to –127.1‰, respectively). The samples of glacier ice form a linear trend within the δD–δ18O coordinates with low slope (s < 7). The isotope signature of water runoff from Severny Island point mainly to the glacial origin of the waters. The isotope parameters of glacial ice from the Novaya Zemlya Archipelago deviated from the values expected for western transfer of air masses under the latitudinal effect compared to glacial ice from other Arctic archipelagoes (Svalbard, Severnaya Zemlya, and Franz Josef Land). These parameters were similar to those for atmospheric precipitation over the continent near the town of Amderma. The slope of the trend, deuterium excess values, and narrow variation range of δD and δ18O values of ice might be caused by seasonal freezing of meltwater in firn layers within the closed system condition.

ПАЛЕОГЕОГРАФИЯ САРТАНСКОГО ОЛЕДЕНЕНИЯ ПАТОМСКОГО И СЕВЕРО-БАЙКАЛЬСКОГО НАГОРИЙ

The article presents the results of the reconstruction of the spatial boundaries and parameters of glaciers for the isolated mountain structures of the Patomsky and North Baikal uplands in the era of the Last Glaciation (MIS 2) with the construction of a paleogeographic map. The object of this study is the dynamics of exogenous processes during the development of the permafrost zone in Eastern Siberia. The subject of research is the glacial relief forms of the Late Neopleistocene of the Patomsky and North Baikal uplands. The comparative, descriptive, cartographic research methods, methods of observation and actualism have been used. Based on the interpretation of aerial and satellite images, the identification of typomorphic glaciers with the maximum number of preserved destructive and accumulative glaciogenic forms, a depression of the snow boundary was established, which at that time was at the level of 2000…2100 m. The features of the lower boundary deformations of the chionosphere were revealed. Its deepest minimum is noted on the northwestern edge of the considered territory. The greatest decrease in relation to the paleoclimatic snow boundary, which extended to an altitude of 1600…1700 m, was 600…700 m. The positive extremum was confined to the central part of the Patom upland and exceeded the paleoclimatic snow line by 50…100 m. Anomalous extremes at that time period are due to global climatic, regional orographic and local (slope exposure) causes. It has been determined that in terms of morphology, glaciation of the territories under consideration is mountain-valley and reticulate with several sections of mountain-cover, confined to the flattened surfaces of the summit belt of mountain structures. According to the difference between the ice surface isolines and the valley bottom in the cross section, the thickness of the glacier was specified, and could reach 400…600 m. When searching for alluvial occurrences and gold deposits, as well as when sampling placer flows and secondary geochemical halos, it is recommended to orient prospecting in the direction of movement of ice masses. The new paleogeographic data obtained will increase the possibilities of more efficient mapping of Quaternary sediments within the North Baikal and Patom uplands and the identification of specific sections of river valleys in this area, favourable for placer formation

Палеогеография Сартанского оледенения хребта Хамар-Дабан (Южное Прибайкалье)

Based on the methods of remote identification and spatial fixation of glacial relief forms with their subsequent geomorphological analysis, the lower boundary of the chionosphere, the glacier feeding areas, boundaries and glacier parameters of the maximum phase of the Last Glacial Maximum glaciers (MIS 2) of the mountainous regions of Southern Baikal region were established and a paleogeographic map was constructed. The object of this study was the dynamics of exogenous processes during the development of the permafrost zone in the Southern Baikal region. The subject of the study is the glacial landforms of the Late Neopleistocene of the Khamar-Daban ridge. Glaciers were reconstructed using absolute marks of destructive and accumulative traces using topographic maps, aerial photographs and satellite images. Paleogeographic constructions were carried out using computer programs Google Earth Pro and SAS. Planet release. The final generalization of the primary material was carried out on a topographic basis on a scale of 1:500,000. The results obtained made it possible to establish the depression of the snow boundary at the maximum of the last cooling at 1300…1400 m in relation to the current climatic and to reveal the features of deformation of the lower border of the chionosphere. The reconstruction of the paleogeographic situation showed the spread of simple and complex (dendritic) types of mountain-valley glaciers, as well as mesh and mountain-glaciation glaciers in some parts of the mountain top. It was established that in the region of the maximum depression of the snowy border, some glaciers reached the coast of Lake Baikal, which could contribute to dilution of secondary aureoles and the displacement of placer mineral deposits. On the southern slope of the Khamar-Daban ridge, the snow boundary passed at an altitude of 1800…2200 m, and glaciation was limited to the development of only circus and circus-valley glaciers of small sizes, contributing to the formation of placers far removed from indigenous sources

On the strongly imbalanced state of glaciers in the Sikkim, eastern Himalaya, India.

This study evaluates multiple glacier parameters (length, area, debris cover, snowline altitude (SLA), glacial lakes, velocity, and surface elevation change) to comprehend the response of poorly understood glaciers of the Sikkim Himalaya to climate change. For the proposed task, 23 representative glaciers were selected from the region, and remotely acquired data from Landsat-TM/ETM/OLI (1991-2017), and Terra-ASTER (2007-2017) along with the SRTM DEMs were used for extraction of the various parameters. Results show that during 1991-2015 the studied glaciers have significantly retreated (17.78 ± 2.06 m a-1), deglaciated (5.44 ± 0.87%), and experienced a considerable increase in SLA (~7 m a-1) and debris cover (16.49 ± 2.96%). Glaciers slowed-down (by 24.90%) with sizable growth in number (23.81%) and area (48.78 ± 2.23%) of glacial lakes. They also exhibit a notable downwasting (-0.77 ± 0.08 m a-1) during 2000-2007/17. The behavior of glaciers in the region is heterogeneous and found to be primarily determined by glacier size, debris cover and glacial lakes. Though a generalized mass loss is observed for both small- (<3 km2) and large-sized glaciers (>10 km2), they seem to adopt different mechanisms to cope with the ongoing climatic changes. While the first adjust mostly by retreat/deglaciation, the latter lose mass through downwasting. Comparing with other Himalayan regions, the magnitude of dimensional changes and debris growth are higher in the Sikkim. The SLA trends are comparable with the central and western Himalaya up to 2000, but a reverse trend is seen afterwards. Also, contrary to the western and central Himalaya, where glaciers are reported to have slowed-down in recent decade, the Sikkim glaciers have shown negligible deceleration after 2000. Climate analysis confirm almost double increase in summer temperature (24.47%) than winters (12.77%) during 1990-2016, which, given the 'summer-accumulation-type' nature of the Sikkim glaciers, seems to be the prime driver of the observed changes.

Evolution of a debris-covered glacier in the western Himalaya during the last four decades (1971–2016): A multiparametric assessment using remote sensing and field observations

This study assesses the response of the Panchi Nala glacier, Bhaga Basin, western Himalaya to climate change by monitoring multiple glacier parameters namely, length, area, debris cover, snowline altitude (SLA), surface ice velocity (SIV), and surface elevation change (Δh). These parameters were analysed using high-resolution satellite images (Corona KH-4B and Sentinel-2 MSI) and medium-resolution ones (Landsat TM/ETM+/OLI and Terra ASTER) acquired between 1971 and 2016, along with extensive field observations. Considering only dimensional changes, the glacier appears to have low rates of recession (4.54 ± 2.56 m y−1) and deglaciation (0.11 ± 0.04% y−1) over the study period (1971–2016). However, SIV and Δh values reveal a significant slowdown (33.87%; 1992/93–2015/16), and an extensive lowering (−1.62 ± 0.06 m y−1; 2000–2013) on the glacier. The debris cover area and SLA also increased by 23.50 ± 1.74% and 287.63 m, respectively, during 1971–2016. Increase in the mean winter minimum temperature, and decrease in the winter snowfall are probably the main drivers of glacier depletion. We conclude that the significant slowdown, extensive surface lowering, development of a proglacial lake and appearance of the supraglacial lakes collectively indicate a severe glacier degeneration. This forewarns that the glacier may experience an accelerated pace of wastage in the future.

Geometry and paleo-ice content of rock glaciers in the southeastern Alps (NE Italy – NW Slovenia)

ABSTRACT Rock glaciers in the southeastern Alps of Slovenia and Italy have been mapped in detail using high resolution digital elevation model and orthophotos, supported by field-based observations. A total of 52 rock glaciers with an area of 3.40 km2 have been delineated on a rock glacier map, divided in 18 sections at a scale of 1:15,000. Several geometrical parameters of rock glaciers have been calculated and their activity degree has been inferred. 90% of rock glaciers have been classified as relict, while the rest are assumed to be of uncertain activity and might still contain some ice. The volumetric ice content and water volume equivalent of the studied rock glaciers for the period of their activity has been calculated to 0.055 ± 0.011 km3 and 0.049 ± 0.010 km3, respectively, which is very close to the ice volume of glaciers reconstructed for this area during the little ice age to 0.069 km3.

Исследование культурного слоя города Челябинска на территории Заречья

In 2016 in the area across the river of the Chelyabinsk city the investigation was carried out of the territory of the Kaslinskaya street to south of the Ryabinin’s famous manor-house (first mentioned in 1885). According to the results of the excavations, it was established that the site under investigation was developed in the second half of the 19th and beginning of the 20th centuries, which confirms the fact that the outskirts of the Zarechye had not been developed at an earlier time.Comparative analysis of the materials with the data of other excavation sites of the cultural layer of Chelyabinsk allowed drawing some preliminary conclusions about the layout of the yard buildings, charting trends in the development of yard cellars in the of 18th – early 20th centuries.In the 18th – first half of the 19th centuries yard cellars were localized in the backyard, behind residential buildings, in close proximity to them. This period is characterized by larger parameters of cellars and glaciers, represented by depressions with logs lowered in them. Yard cellars of the second half of the 19th – the beginning of the 20th century are somewhat reduced in size, they can be found far from the house and be made of lining boards and bricks. Reduction of the size of cellars at the turn of the 19th – 20th centuries, can probably be attributed to the spread of homes on the foundation with an extensive underground, when the yard cellars become optional to store food.

Glacier recession in the Altai Mountains of Mongolia in 1990–2016

ABSTRACTRelatively little is known about glaciers in the continental climates of North Asia and even less is known about the glaciers of the Mongolian Altai. In an attempt to fill this knowledge gap, we present a new satellite-derived glacier inventory for the Altai Mountains of Mongolia, using the recently launched Landat-8 OLI and Sentinel-2A MSI sensors to monitor glacier change from 1990 to 2016. We examine changes in climatic trends and glacier topomorphological parameters in conjunction with glacier fluctuations to determine governing controls over glacier recession in the Altai Mountains. Our glacier mapping results produced 627 debris-free glaciers with an area of 334.0 ± 42.3 km2 as of 2016. These data were made available for download through the Global Land Ice Measurements from Space (GLIMS) initiative. A subsample of 206 glaciers that were mapped in 1990, 2000, 2010, and 2016 revealed that from 1990 to 2016, glacier area reduced by 43% at 6.4 ± 0.4 km2 yr−1. Glacier recession was greatest from 1990 to 2000 at a rate of 10.9 ± 0.8 km2 yr−1, followed by 2010–2016 at 4.4 ± 0.3 km2 yr−1. Rates of glacier recession were significantly correlated with intrinsic glacier parameters, including mean, minimum and range elevations, mean slope and aspect. Furthermore, climate records indicated the warmest summer temperatures occurred during periods of high glacier recession.

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.

Assessing linkages between spatial facies changes and dimensional variations of glaciers in the upper Indus Basin, western Himalaya

The present study provides an insight into the heterogeneous response of 45 glaciers in the Lidder and Sindh river basins, western Himalaya, and explores the linkages between glacier facies variability and changing glacier parameters. Results show that the region has undergone an overall deglaciation of ~12±1.5% (11.9±1.4km2) from 1996 to 2014. Fluctuations in the temperature and precipitation patterns seem to be the primary factor controlling the changes in glacier dimensions (R2>0.82 in all cases). Glacier facies changes suggest depletion in snow-ice cover (~18±2.3%) and an increase in ice-mixed debris (~4±1.4%), supraglacial debris (~6±1.5%), and periglacial debris (~17±1.2%). These glacier facies transitions are possibly the result of ice-melting; however, its relative rate and elevation decides the nature of facies conversion. An increase in the proportion of supraglacial debris has led to the conversion of 11 clean glaciers to sparsely debris-covered glaciers and 5 sparsely debris-covered glaciers to debris-covered glaciers. The size of the glaciers greatly influenced the rate of conversion of glaciers, and glaciers <2km2 dominated the others in this regard. The small glaciers also experienced maximum shrinkage. Further, the glaciers with varying supraglacial debris cover respond differently, as sparsely debris-covered glaciers exhibit the highest rates of retreat (25±7.3m/y), followed by clean (23.7±7.3m/y) and debris-covered glaciers (13.1±7.3m/y). Thus, the findings of this work clearly show that the climate change driven dimensional changes of glaciers and variations in the spatial distribution of glacier facies have strong mutual control on each other.