Changes in the elevation and extent of two glaciers along the Yanglonghe river, Qilian Shan, China

AbstractWe use topographic maps, historical data, multispectral satellite data and real-time kinematic GPS data to analyze glacier area, length and ice-elevation changes of two glaciers in the central Qilian Shan, China, between 1956 and 2007. We find that the fronts of Yanglonghe glacier No. 1 (5Y432A1) and Yanglonghe glacier No. 5 (5Y432A5) have retreated by 266.5 ± 37.1 m (5.2 ± 0.73 m a−1) and 181.4 ± 37.1 m (3.6 ± 0.73 m a−1) respectively, and that this retreat accelerated after 1999. During the study period, the glacier areas decreased by ∼4.1% and 15.9% respectively. In addition, spatially non-uniform thinning, which averaged 20.2 ± 11 m (0.4 ± 0.22 m a−1) and 16.9 ± 11 m (0.33 ± 0.22 m a−1) in the ablation areas of 5Y432A1 and 5Y432A5 respectively, is observed using digital elevation models constructed using data from 1956, 1977 and 2007. The ice-volume depletion from 5Y432A1 (2.91 × 107 m3) was 2.7 times greater than from the smaller 5Y432A5 (1.08 × 107 m3). Based on records from nearby Tuole weather station, increasing annual temperatures are principally responsible for the observed glacier thinning and retreat.

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Glacier mass balance over the central Nyainqentanglha Range during recent decades derived from remote-sensing data

Journal of Glaciology ◽

10.1017/jog.2019.20 ◽

2019 ◽

Vol 65 (251) ◽

pp. 422-439 ◽

Cited By ~ 5

Author(s):

KUNPENG WU ◽

SHIYIN LIU ◽

ZONGLI JIANG ◽

JUNLI XU ◽

JUNFENG WEI

Keyword(s):

Mass Balance ◽

Remote Sensing Data ◽

Shuttle Radar Topography Mission ◽

Topographic Maps ◽

Glacier Mass Balance ◽

Glacier Area ◽

Ice Surface ◽

Digital Elevation ◽

Elevation Changes ◽

Elevation Model

ABSTRACTTo obtain information on changes in glacier mass balance in the central Nyainqentanglha Range, a comprehensive study was carried out based on digital-elevation models derived from the 1968 topographic maps, the Shuttle Radar Topography Mission DEM (2000) and TerraSAR-X/TanDEM-X (2013). Glacier area changes between 1968 and 2016 were derived from topographic maps and Landsat OLI images. This showed the area contained 715 glaciers, with an area of 1713.42 ± 51.82 km2, in 2016. Ice cover has been shrinking by 0.68 ± 0.05% a−1 since 1968. The glacier area covered by debris accounted for 11.9% of the total and decreased in the SE–NW directions. Using digital elevation model differencing and differential synthetic aperture radar interferometry, a significant mass loss of 0.46 ± 0.10 m w.e. a−1 has been recorded since 1968; mass losses accelerated from 0.42 ± 0.20 m w.e. a−1 to 0.60 ± 0.20 m w.e. a−1 between 1968–2000 and 2000–2013, with thinning noticeably greater on the debris-covered ice than the clean ice. Surface-elevation changes can be influenced by ice cliffs, as well as debris cover and land- or lake-terminating glaciers. Changes showed spatial and temporal heterogeneity and a substantial correlation with climate warming and decreased precipitation.

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2001–2009 elevation and mass losses in the Larsen A and B embayments, Antarctic Peninsula

Journal of Glaciology ◽

10.3189/002214311797409811 ◽

2011 ◽

Vol 57 (204) ◽

pp. 737-754 ◽

Cited By ~ 46

Author(s):

Christopher A. Shuman ◽

Etienne Berthier ◽

Ted A. Scambos

Keyword(s):

Antarctic Peninsula ◽

Loss Rate ◽

Ice Shelf ◽

Laser Altimetry ◽

Ice Shelves ◽

Ice Volume ◽

Mass Losses ◽

Digital Elevation ◽

Modis Imagery ◽

Elevation Changes

AbstractWe investigate the elevation and mass-balance response of tributary glaciers following the loss of the Larsen A and B ice shelves, Antarctic Peninsula (in 1995 and 2002 respectively). Our study uses MODIS imagery to track ice extent, and ASTER and SPOT5 digital elevation models (DEMs) plus ATM and ICESat laser altimetry to track elevation changes, spanning the period 2001–09. The measured Larsen B tributary glaciers (Hektoria, Green, Evans, Punchbowl, Jorum and Crane) lost up to 160 m in elevation during 2001–06, and thinning continued into 2009. Elevation changes were small for the more southerly Flask and Leppard Glaciers, which are still constrained by a Larsen B ice shelf remnant. In the northern embayment, continued thinning of >3 m a−1 on Drygalski Glacier, 14 years after the Larsen A ice shelf disintegrated, suggests that mass losses for the exposed Larsen B tributaries will continue for years into the future. Grounded ice volume losses exceed 13 km3 for Crane Glacier and 30 km3 for the Hektoria–Green–Evans glaciers. The combined mean loss rate for 2001–06 is at least 11.2 Gt a−1. Our values differ significantly from published mass-budget-based estimates for these embayments, but are a reasonable fraction of GRACE-derived rates for the region (∼40 Gt a−1).

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A first approximation of the volume of ground ice, Richards Island, Pleistocene Mackenzie delta, Northwest Territories, Canada

Canadian Geotechnical Journal ◽

10.1139/t80-059 ◽

1980 ◽

Vol 17 (4) ◽

pp. 509-516 ◽

Cited By ~ 76

Author(s):

W. H. Pollard ◽

H. M. French

Keyword(s):

Data Bank ◽

Topographic Maps ◽

Mackenzie Delta ◽

Ground Ice ◽

Geotechnical Data ◽

Ice Volume ◽

First Approximation ◽

Arctic Alaska ◽

Morphometric Analyses ◽

Using Data

Using data contained in the Mackenzie Valley Geotechnical Data Bank together with data derived from morphometric analyses of topographic maps and air photographs, the volume of ground ice present in the upper 10 m of Richards Island is calculated to be 10.27 km3. Pore and segregated ice constitute over 80% of the total ice volume. Wedge ice constitutes between 12 and 16% of total ice volume in the upper 4.5 m, and approximately 36% of all excess ice. In the upper 1–2 m, wedge ice may exceed 50% of earth materials. Pingo ice is insignificant in terms of its contribution to total ice volumes. Excess ice constitutes 14% of the upper 10 m of permafrost; it follows that thawing of this layer of permafrost may lead to an average subsidence of 1.4 m.The results of this study are probably typical of other areas of the Pleistocene Mackenzie delta. There is also general agreement with data obtained from arctic Alaska.

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Multi-temporal airborne LIDAR-DEMs for glacier and permafrost mapping and monitoring

The Cryosphere Discussions ◽

10.5194/tcd-3-383-2009 ◽

2009 ◽

Vol 3 (2) ◽

pp. 383-414 ◽

Cited By ~ 5

Author(s):

J. Abermann ◽

A. Fischer ◽

A. Lambrecht ◽

T. Geist

Keyword(s):

Airborne Lidar ◽

Aerial Photographs ◽

Good Representation ◽

Glacier Area ◽

Covered Area ◽

Digital Elevation ◽

Multi Temporal ◽

Elevation Changes ◽

Remote Sensing Techniques ◽

Permafrost Mapping

Abstract. The proposed method presents a simple and robust way to derive glacier extent by using multi-temporal high-resolution DEMs (digital elevation models) as a main data source. For glaciers that are not debris covered, we perform the glacier boundary delineation by analysing roughness differences between ice and its surroundings. A promising way to distinguish dead ice, debris-covered ice or permafrost from its rocky surroundings is shown by taking elevation changes from DEMs of different dates into consideration. In case data has a high spatial and temporal resolution a good representation of the extent of debris cover and thus the overall ice covered area can be given. We use examples to show how potentially ambiguous areas can be treated decisively by the additional qualitative analysis of aerial photographs. Problems and limitations are discussed in comparison with selected other remote sensing techniques and accuracies are quantified. For glaciers larger than 1 km2 an accuracy of ±1% of the glacier area could be assessed. The errors of smaller glaciers do not exceed ±5% of the glacier area.

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Remote-sensing estimate of glacier mass balance over the central Nyainqentanglha Range during 1968 – ∼ 2013

10.5194/tc-2018-90 ◽

2018 ◽

Author(s):

Kunpeng Wu ◽

Shiyin Liu ◽

Zongli Jiang ◽

Junli Xu ◽

Junfeng Wei

Keyword(s):

Mass Balance ◽

Recent Decade ◽

Shuttle Radar Topography Mission ◽

Quality Data ◽

Glacier Mass Balance ◽

Glacier Area ◽

Ice Surface ◽

Air Temperatures ◽

Digital Elevation ◽

Elevation Changes

Abstract. With high air temperatures and annual precipitation, maritime glaciers in southeastern Tibet are sensitive to climate change. Current glaciological knowledge of those in the central Nyainqentanglha Range is still limited because of their inaccessibility and low-quality data. To obtain information on changes in glacier area, length and mass balance, a comprehensive study was carried out based on topographic maps and Landsat TM/ETM+/OLI images (1968 and 2016), and on digital-elevation models (DEM) derived from the 1968 maps, from the Shuttle Radar Topography Mission (SRTM) DEM (2000), and from TerraSAR-X/TanDEM-X (∼ 2013). This showed the area contained 715 glaciers, with an area of 1713.42 ± 51.82 km2, in 2016. Ice cover has been shrinking by 0.68 % ± 0.05% a−1 since 1968, although in the most recent decade this rate has slowed. The glacier area covered by debris accounted for 11.9 % of the total and decreased in SE-NW directions. Using DEM differencing and Differential Synthetic Aperture Radar Interferometry (DInSAR), a significant mass deficit of 0.46 ± 0.04 m w.e. a−1 has been recorded since 1968; mass losses accelerating from 0.42 ± 0.05 m w.e. a−1 to 0.60 ± 0.20 m w.e. a−1 during 1968–2000 and 2000–∼ 2013, with thinning noticeably greater on the debris-covered ice than the clean ice. Surface-elevation changes can be influenced by ice cliffs, as well as debris cover, and land- or lake-terminating glaciers and supraglacial lakes. Changes showed spatial and temporal heterogeneity and a substantial correlation with climate warming.

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Brief communication: The Khurdopin glacier surge revisited – extreme flow velocities and formation of a dammed lake in 2017

The Cryosphere ◽

10.5194/tc-12-95-2018 ◽

2018 ◽

Vol 12 (1) ◽

pp. 95-101 ◽

Cited By ~ 23

Author(s):

Jakob F. Steiner ◽

Philip D. A. Kraaijenbrink ◽

Sergiu G. Jiduc ◽

Walter W. Immerzeel

Keyword(s):

Landsat Imagery ◽

Mountain Glacier ◽

Ice Volume ◽

Driving Mechanisms ◽

High Resolution Imagery ◽

Digital Elevation ◽

Elevation Changes ◽

Glacier Surges ◽

Planet Satellite ◽

Flow Velocities

Abstract. Glacier surges occur regularly in the Karakoram, but the driving mechanisms, their frequency and its relation to a changing climate remain unclear. In this study, we use digital elevation models and Landsat imagery in combination with high-resolution imagery from the Planet satellite constellation to quantify surface elevation changes and flow velocities during a glacier surge of the Khurdopin Glacier in 2017. Results reveal that an accumulation of ice volume above a clearly defined steep section of the glacier tongue since the last surge in 1999 eventually led to a rapid surge in May 2017 peaking with velocities above 5000 m a−1, which were among the fastest rates globally for a mountain glacier. Our data reveal that velocities on the lower tongue increase steadily during a 4-year build-up phase prior to the actual surge only to then rapidly peak and decrease again within a few months, which confirms earlier observations with a higher frequency of available velocity data. The surge return period between the reported surges remains relatively constant at ca. 20 years. We show the potential of a combination of repeat Planet and ASTER imagery to (a) capture peak surge velocities that are easily missed by less frequent Landsat imagery, (b) observe surface changes that indicate potential drivers of a surge and (c) monitor hazards associated with a surge. At Khurdopin specifically, we observe that the surging glacier blocks the river in the valley and causes a lake to form, which may grow in subsequent years and could pose threats to downstream settlements and infrastructure in the case of a sudden breach.

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Glacier changes in the Austrian Alps during the last three decades, derived from the new Austrian glacier inventory

Annals of Glaciology ◽

10.3189/172756407782871341 ◽

2007 ◽

Vol 46 ◽

pp. 177-184 ◽

Cited By ~ 106

Author(s):

A. Lambrecht ◽

M. Kuhn

Keyword(s):

State Of The Art ◽

Aerial Photographs ◽

Glacier Area ◽

Glacier Inventory ◽

Ice Volume ◽

Covered Area ◽

Digital Elevation ◽

Glacier Changes ◽

Wide Variability ◽

Almost All

AbstractBeginning in 1996, aerial photographs were taken for a new Austrian glacier inventory, resulting in digital elevation models (DEMs) and digital orthoimages. An earlier inventory of the Austrian glaciers containing the original aerial photographs and glacier maps and a manual evaluation of various glacier parameters as of 1969 has been re-evaluated at the present state of the art. The two inventories provide the basis for the comparison of glacier reactions over a period of 29 years. In general a reduction of glacier area is observed for almost all Austrian glaciers between 1969 and 1998. The overall reduction in ice-covered area is 17%. The glacier volume change calculated from the DEMs amounts to about 5 km3. This is almost 22% of the ice volume in Austria in 1969, estimated from a volume–area relation. Changes of individual glaciers, however, show a wide variability, depending on their size and physiographic setting.

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Glacier elevation and mass changes over the central Karakoram region estimated from TanDEM-X and SRTM/X-SAR digital elevation models

Annals of Glaciology ◽

10.3189/2016aog71a024 ◽

2016 ◽

Vol 57 (71) ◽

pp. 273-281 ◽

Cited By ~ 53

Author(s):

Melanie Rankl ◽

Matthias Braun

Keyword(s):

High Resolution ◽

Snow Cover ◽

Digital Elevation Models ◽

Mass Balances ◽

Freshwater Resources ◽

Digital Elevation ◽

Glacier Changes ◽

Kinematic Waves ◽

Elevation Changes ◽

River Communities

AbstractSnow cover and glaciers in the Karakoram region are important freshwater resources for many down-river communities as they provide water for irrigation and hydropower. A better understanding of current glacier changes is hence an important informational baseline. We present glacier elevation changes in the central Karakoram region using TanDEM-X and SRTM/X-SAR DEM differences between 2000 and 2012. We calculated elevation differences for glaciers with advancing and stable termini or surge-type glaciers separately using an inventory from a previous study. Glaciers with stable and advancing termini since the 1970s showed nearly balanced elevation changes of -0.09 ±0.12 m a-1 on average or mass budgets of -0.01 ±0.02Gt a-1 (using a density of 850 kg m-3). Our findings are in accordance with previous studies indicating stable or only slightly negative glacier mass balances during recent years in the Karakoram. The high-resolution elevation changes revealed distinct patterns of mass relocation at glacier surfaces during active surge cycles. The formation of kinematic waves at quiescent surge-type glaciers could be observed and points towards future active surge behaviour. Our study reveals the potential of the TanDEM-X mission to estimate geodetic glacier mass balances, but also points to still existing uncertainties induced by the geodetic method.

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A New Approach to the Quality Control of Slope and Aspect Classes Derived from Digital Elevation Models

Remote Sensing ◽

10.3390/rs13112069 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2069

Author(s):

M. V. Alba-Fernández ◽

F. J. Ariza-López ◽

M. D. Jiménez-Gamero

Keyword(s):

Quality Control ◽

Hypothesis Test ◽

Simulated Data ◽

Slope Aspect ◽

New Approach ◽

Reference Set ◽

Digital Elevation ◽

Using Data ◽

Elevation Model ◽

Degree Of Similarity

The usefulness of the parameters (e.g., slope, aspect) derived from a Digital Elevation Model (DEM) is limited by its accuracy. In this paper, a thematic-like quality control (class-based) of aspect and slope classes is proposed. A product can be compared against a reference dataset, which provides the quality requirements to be achieved, by comparing the product proportions of each class with those of the reference set. If a distance between the product proportions and the reference proportions is smaller than a small enough positive tolerance, which is fixed by the user, it will be considered that the degree of similarity between the product and the reference set is acceptable, and hence that its quality meets the requirements. A formal statistical procedure, based on a hypothesis test, is developed and its performance is analyzed using simulated data. It uses the Hellinger distance between the proportions. The application to the slope and aspect is illustrated using data derived from a 2×2 m DEM (reference) and 5×5 m DEM in Allo (province of Navarra, Spain).

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Aufeis of the Indigirka river basin (Russia): the database from historical data and recent Landsat images

10.5194/essd-2018-99 ◽

2018 ◽

Author(s):

Olga Makarieva ◽

Andrey Shikhov ◽

Nataliia Nesterova ◽

Andrey Ostashov

Keyword(s):

Interannual Variability ◽

20Th Century ◽

Historical Data ◽

Topographic Maps ◽

Landsat Images ◽

North East ◽

The North ◽

Digital Database ◽

Formation Conditions ◽

Basin Area

Abstract. Detailed spatial geodatabase of aufeis in the Indigirka River, the basin area 305 000 km2, Russia was compiled from the Cadaster of aufeis of the North-East of the USSR published in 1958, topographic maps and Landsat images for 2013–2017. The aufeis area share varies from 0.26 to 1.15 % in different river sub-basins within the studied area. Digitized Cadaster (1958) contains the coordinates and characteristics of 897 aufeises with total area of 2064 km2. The Landsat-based identification of aufeises for 2013–2017 allowed the description of 1213 aufeises on a total area of 128 km2. The combined digital database of the aufeis is available at https://doi.pangaea.de/10.1594/PANGAEA.891036. The satellite-derived total area of aufeis is 1.6 times less than in the Cadaster (1958). At the same time, more than 600 aufeis identified by Landsat images analyses are missing in the Cadaster (1958). It implies that the aufeis formation conditions may have been changed between the mid-20th century and the present. About 60 % of total area presents 10 % of the largest aufeis. Most aufeis are located in the elevation band of 1100–1300 m. The interannual variability of the aufeis area was estimated by the example of the Bolshaya Momskaya naled (aufeis) and the group of large aufeis in the basin of the Syuryuktyakh River for the period of 2001–2016. The results of analysis indicate a tendency towards a decrease in the area of the Bolshaya Momskaya naled in recent years, at the same time the reduction in the aufeis area in the basin of the Syuryuktyakh River has not occurred.

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