scholarly journals Glacier Changes and Their Linkage to the Climate-Topographic Context in the Borohoro Mountains, Tian Shan 1977–2018

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1502
Author(s):  
Yanan Li
Keyword(s):  
Climatic Factors ◽  
Warming Trend ◽  
Shuttle Radar Topography Mission ◽  
Surface Elevation ◽  
Glacier Area ◽  
Glacier Changes ◽  
Sentinel 2A ◽  
Essential Knowledge ◽  
Correlated Parameters ◽  
Tian Shan

Against the backdrop of climate change and socio-ecological sustainability, studying glacier changes provides essential knowledge to the basic water needs and security for regions and populations under such threats, such as Central Asia. Little attention has focused on glaciers in the northern periphery of the Chinese Tian Shan. This study aims to map a recent glacier inventory and examine the glacier area shrinkage and surface elevation change for the central massif of the Borohoro Mountains in the past 41 years. Using declassified Hexagon images (1977), Landsat 5 TM (1994 and 2007), Sentinel 2A (2018) and altimetry data from the Ice, Cloud and Land Elevation Satellite (ICESat) over 2003–2009 with the 30-m Shuttle Radar Topography Mission (SRTM) digital elevation model, multi-temporal glacier fluctuations and the influence of topographic and climatic factors were investigated. Results show that the glacier area decreased from 287.5 ± 8.2 km2 in 1977 to 215.8 ± 4.1 km2 in 2018, at a rate of 0.61 ± 0.01% year−1. Glacier disintegration has led to a gradual increase in the number of glaciers and reached 224 glaciers in 2018. The shrinkage was at the highest rate during the 1994–2007 period and the smallest during 1977–1994. Glacier size, hypsometry, and median, maximum, and range of elevation are the most significantly correlated parameters with the relative area change. The surface elevation changes from two of the largest glaciers revealed a stronger thinning on the southern slope compared to the northern slope. These observations of glacier loss are primarily driven by the marked warming trend since the 1970s and confirmed with the overall pattern of glacier retreat in the Tian Shan from previous studies.

scholarly journals Glacier changes between 1971 and 2016 in the Jankar Chhu Watershed, Lahaul Himalaya, India

2018 ◽  
Vol 65 (249) ◽  
pp. 13-28 ◽  
Author(s):  
SURESH DAS ◽  
MILAP CHAND SHARMA
Keyword(s):  
Cloud Cover ◽  
Thematic Mapper ◽  
Landsat Thematic Mapper ◽  
Field Observations ◽  
Glacier Area ◽  
Ablation Zone ◽  
Change Analysis ◽  
Recession Rate ◽  
Glacier Changes ◽  
Sentinel 2A

ABSTRACTGlacier changes in the Jankar Chhu Watershed (JCW) of Chandrabhaga (Chenab) basin, Lahaul Himalaya were worked out based on Corona and Sentinel 2A images between 1971 and 2016. The JCW consists of 153 glaciers (>0.02 km2) with a total area of 185.6 ± 3.8 km2that include 82 glaciers with debris-covered ablation zone, comprising 10.9% of the total glacierized area as in 2016. Change analysis based on Corona (1971), Landsat (2000) and Sentinel 2A (2016) was restricted to 127 glaciers owing to the presence of cloud cover on 26 glaciers in 1971. A subset of glaciers was also mapped using Landsat Thematic Mapper (TM; 1989) image. The total glacier area decreased by 14.7 ± 4.3 km2(0.3 ± 0.1 km2a−¹). The number of glaciers in the JCW increased by four between 1971 and 2016 due to fragmentation. More recently (2000–16), recession rate has increased. Clean-ice area decreased by 21.8 ± 3.8 km2(0.5 ± 0.1 km2a−¹) while debris-covered ice increased by 7.2 ± 0.4 km2(0.2 ± 0.01 km2a−¹). Field observations of select glaciers also support derived recession trend in the JCW. Retreat rates in the JCW have been observed to be much lower than previously reported.

scholarly journals Topographic and geometric controls on glacier changes in the central Tien Shan, China, since the Little Ice Age

2014 ◽  
Vol 55 (66) ◽  
pp. 177-186 ◽  
Author(s):  
Yanan Li ◽  
Yingkui Li
Keyword(s):  
Little Ice Age ◽  
Climatic Factors ◽  
Google Earth ◽  
Tien Shan ◽  
Ice Age ◽  
Slope Aspect ◽  
Glacier Area ◽  
Equilibrium Line Altitude ◽  
Local Factors ◽  
Glacier Changes

AbstractThis paper examines the topographic and geometric controls on glacier changes in area and equilibrium-line altitude (ELA) in the central Tien Shan, China, since the Little Ice Age (LIA). We delineate the extents of 487 modern glaciers and their corresponding maximum LIA glacial advances using satellite imagery in Google Earth, and analyze the relationships between the magnitude of glacier changes and a set of local topographic/geometric factors including glacier area, slope, aspect, shape, hypsometry and mean elevation. Our results show that: (1) glacier area decreased from 460.2 km2 during the LIA to 265.6 km2 in the 2000s (a loss of 42.3%), with an average ELA increase of ~100m; (2) relative area changes of glaciers are strongly affected by two of these local factors (glacier area and mean elevation); and (3) ELA change does not show a strong relationship with local factors, suggesting that it may be controlled mainly by climatic factors. This study provides important insights into the local controls on glacier changes at the centennial timescale, which are of critical importance to assess future glacier changes in this arid and semi-arid region.

scholarly journals Spatially Variable Glacier Changes in the Annapurna Conservation Area, Nepal, 2000 to 2016

2019 ◽  
Vol 11 (12) ◽  
pp. 1452 ◽  
Author(s):  
Arminel M. Lovell ◽  
J. Rachel Carr ◽  
Chris R. Stokes
Keyword(s):  
Surface Elevation ◽  
Glacier Area ◽  
Elevation Change ◽  
Conservation Area ◽  
Future Evolution ◽  
The North ◽  
Glacier Changes ◽  
Surface Elevation Change ◽  
Annapurna Conservation Area ◽  
The Mean

Himalayan glaciers have shrunk rapidly in recent decades, but the spatial pattern of ice loss is highly variable and appears to be modulated by factors relating to individual glacier characteristics. This hinders our ability to predict their future evolution, which is vital for water resource management. The aim of this study is to assess recent glacier changes in the little-studied Annapurna Conservation Area (ACA; area: 7629 km2) in Nepal, and to explore local controls influencing their behaviour. We map changes in glacier area, surface elevation, and ice flow velocity on a large sample of glaciers (n = 162) in the ACA between 2000 and 2016. We found that total glacier area decreased by 8.5% between 2000 and 2014/15. Ice surface velocity changes between 2002 and 2016 were variable, with no clear trend of acceleration or deceleration. The mean surface elevation change for a smaller sample of glaciers (n = 72) was −0.33 ± 0.22 m a−1 between 2000 and 2013/16, which equates to a mean mass balance of −0.28 ± 0.24 m w.e. a−1. There was a trend of increasingly less negative mass balance towards the north. Glaciers that lost the most mass in the north of the ACA tended to have lower maximum elevations, bottom-heavy hypsometries, and were more likely to be avalanche-fed. However, these patterns were not apparent in glaciers in central ACA. There was no significant difference in the mean surface elevation change rate on the ablation zones of debris-covered compared with debris-free glaciers. Our work shows that glaciers in the ACA are losing area and mass at variable rates, but that the influence of local controls is complex, which introduces large uncertainties when predicting their future evolution.

scholarly journals Elevation changes of Inylchek Glacier during 1974–2007, Central Tian Shan, Kyrgyzstan derived from remote sensing data

2014 ◽  
Vol 8 (3) ◽  
pp. 2573-2610 ◽  
Author(s):  
D. Shangguan ◽  
T. Bolch ◽  
Y. Ding ◽  
M. Kröhnert ◽  
T. Pieczonka ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Data ◽  
Main Flow ◽  
Surface Elevation ◽  
Glacier Area ◽  
Glacier Surface ◽  
Sensing Data ◽  
Multi Temporal ◽  
Southern Branch ◽  
Tian Shan

Abstract. Glacier melt is an important source of fresh water for the arid regions surrounding the Tian Shan. Inylchek Glacier (650 km2) is the largest glacier in Tian Shan consisting of two branches (northern Inylchek glacier and southern Inylchek glacier) separated by the regularly draining Lake Merzbacher. However, little is known about volume and mass changes of the last decades. In this study, we investigated the changes of glacier area and glacier surface elevation from 1974 until 2007 and the surface velocity between 2003 and 2011 using multi-temporal remote-sensing data. The main flow direction of Southern Inylchek Glacier tongue showed strong velocities of ∼100 m a−1 with a slight decreasing tendency between 2002/03 and 2010/11. The end of the tongue however, is likely stagnant as the main flow is directed towards Lake Merzbacher. The total glacier area increased by 1.3 ± 0.1 km2 (∼0.2%) within the studies period though southern Inylchek Glacier shrank consecutive since 1974. The overall area gain was caused by the strong increase of northern Inylchek Glacier of 3.7 ± 0.3 km2 between 1990–1999. A comparison of glacier surface elevation using multi-temporal digital elevation models derived from KH9-Hexagon (1974), SRTM (1999), ALOS (2006) and SPOT5-HRG (2007) revealed an overall elevation difference of Inylchek Glacier of −0.5 ± 0.1 m a−1 for the period of 1974–2007. The northern glacier branch showed on average no significant surface elevation change (0.1 ± 0.1 m a−1) during 1974 and 2007 while a significant lowering of 0.7 ± 0.1 m a−1 was observed for the southern branch. The overall negative values are mainly due to the period 1974–1999. A possible thickening of 0.5 ± 0.5 m a−1 occurred between 1999 and 2007 where a clear thickening was measured in the accumulation area of the southern branch. We also identified the thickening with a maximum of about ∼150 m close to the end of the northern Inylchek Glacier tongue for the period 1974–1999. This is possibly due to a surge event which happened between 1990 and 1999 according to the area change data. The ablation region of southern Inylchek Glacier showed considerable lowering rates especially in the distal part of the tongue with low velocity despite thick debris coverage.

scholarly journals Glacier changes over the past 144 years at Alexandra Fiord, Ellesmere Island, Canada

2021 ◽  
pp. 1-12
Author(s):  
Allison N. Curley ◽  
William H. Kochtitzky ◽  
Benjamin R. Edwards ◽  
Luke Copland
Keyword(s):  
Average Rate ◽  
Ellesmere Island ◽  
Surface Elevation ◽  
Aerial Photographs ◽  
Field Observations ◽  
Glacier Area ◽  
The Past ◽  
Rates Of Change ◽  
Glacier Changes ◽  
The Mean

Abstract In this study, we use aerial photographs, satellite imagery and field observations to quantify changes in the area, terminus length, snowline elevation and surface elevation of eight glaciers in the Alexandra Fiord region, eastern Ellesmere Island, between 1959 and 2019. Comparisons to written and pictorial descriptions from the British Arctic Expedition extend the record of change in terminus position and surface elevation to 1875 for Twin Glacier. Glacier area at Alexandra Fiord decreased by a total of 15.77 ± 0.65 km2 (11.77 ± 0.49%) between 1959 and 2019, the mean end of summer snowline increased in elevation by 360 ± 84 m (8 ± 2 m a−1) between 1974 and 2019, and the glaciers thinned at an average rate of 0.60 ± 0.06 m a−1 between 2001 and 2018. Annual rates of terminus retreat were ~3–5 times higher over the period 1974–2019 compared to 1875–1974, and rates of thinning were ~2–3 times higher over 2001–18 compared to 1875–2001. Our results are consistent with rates of change determined for other glaciers of similar size on Ellesmere Island, and with accelerated rates of ice loss coincident with regional increases in air temperature of ~1.5°C since the early 1980s.

scholarly journals Compiling a new glacier inventory for southeastern Qinghai–Tibet Plateau from Landsat and PALSAR data

2016 ◽  
Vol 62 (233) ◽  
pp. 579-592 ◽  
Author(s):  
LINGHONG KE ◽  
XIAOLI DING ◽  
LEI ZHANG ◽  
JUN HU ◽  
C. K. SHUM ◽  
...  
Keyword(s):  
Shuttle Radar Topography Mission ◽  
Tibet Plateau ◽  
Landsat 8 ◽  
Glacier Change ◽  
Glacier Area ◽  
Glacier Inventory ◽  
Radar Images ◽  
Water Classification ◽  
Multi Temporal ◽  
Classification Information

ABSTRACTGlacier change has been recognized as an important climate variable due to its sensitive response to climate change. Although there are a large number of glaciers distributed over the southeastern Qinghai–Tibetan Plateau, the region is poorly represented in glacier databases due to seasonal snow cover and frequent cloud cover. Here, we present an improved glacier inventory for this region by combining Landsat observations acquired over 2011–13 (Landsat 8/OLI and Landsat TM/ETM+), coherence images from Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar images and the Shuttle Radar Topography Mission (SRTM) DEM. We present a semi-automated scheme for integrating observations from multi-temporal Landsat scenes to mitigate cloud obscuration. Further, the clean-ice observations, together with coherence information, slope constraints, vegetation cover and water classification information extracted from the Landsat scenes, are integrated to determine the debris-covered glacier area. After manual editing, we derive a new glacier inventory containing 6892 glaciers >0.02 km2, covering a total area of 6566 ± 197 km2. This new glacier inventory indicates gross overestimation in glacier area (over 30%) in previously published glacier inventories, and reveals various spatial characteristics of glaciers in the region. Our inventory can be used as a baseline dataset for future studies including glacier change assessment.

scholarly journals Glacier Changes in the Chhombo Chhu Watershed of Tista basin between 1975 and 2018, Sikkim Himalaya, India

2021 ◽  
Author(s):  
Arindam Chowdhury ◽  
Milap Chand Sharma ◽  
Sunil Kumar De ◽  
Manasi Debnath
Keyword(s):  
Large Population ◽  
Eastern Himalaya ◽  
Glacier Area ◽  
Change Analysis ◽  
Sikkim Himalaya ◽  
Mountain Communities ◽  
Area Loss ◽  
Landsat 7 ◽  
Landsat 5 Tm ◽  
Sentinel 2A

Abstract. Glaciers of the Tista basin represent an important water resource for mountain communities and large population downstream. The present article attempts to assess the observable changes in the glacier area in the Chhombo Chhu Watershed (CCW) of Tista basin, Sikkim Himalaya. The CCW consists of 74 glaciers (>0.02 km2) with a mean glacier size of 0.61 km2. The change of such glacier outlines obtained from the declassified hexagon KH-9 (1975), Landsat 5 TM (1989), Landsat 7 ETM+ (2000), Landsat 5 TM (2010), and Sentinel 2A (2018). The total glacier area in 1975 was 62.6 ±0.7 km2; by 2018, the area had decreased to 44.8 ±1.5 km2, an area loss of 17.9 ± 1.7 km2 (0.42 ± 0.04 km2 a−1). Debris free glaciers exhibit more area loss by 11.8 ± 1.2 km2 (0.27 ± 0.03  km2 a−1) followed by partially debris-covered (5.0 ± 0.4 km2 or 0.12 ± 0.01 km2 a−1) and maximum debris-covered (1.0 ± 0.1 km2 or −0.02 ± 0.002 km2 a−1) glaciers. The quantum of glacier area loss in the CCW of Sikkim Himalaya took its pace during 2000–2010 (0.62 ± 0.5 km2 a−1) and 2010–2018 (0.77 ± 0.6 km2 a−1) timeframes. Field investigations of selected glaciers and climatic records also support the trend in glacier recession in the CCW due to a significant increase in temperature trend and more or less static precipitation since 1995. Glacier retreat rates in the CCW were almost similar to the Changme Khangpu basin and other selected glaciers in Sikkim Himalaya. This glacier inventory and area change analysis will provide valuable information to the glaciological and hydrological community to model and plan the water resources in the Sikkim state of Eastern Himalaya. The dataset is now available from the Zenodo web portal: http://doi.org/10.5281/zenodo.4457183 (Chowdhury et al., 2021).

An update on recent glacier changes in Mexico using Sentinel-2A data

2018 ◽  
Vol 100 (3) ◽  
pp. 307-318 ◽  
Author(s):  
Bijeesh Kozhikkodan Veettil ◽  
Shanshan Wang
Keyword(s):  
Glacier Changes ◽  
Sentinel 2A

scholarly journals Recent retreat of the Elbrus glacier system

2016 ◽  
Vol 62 (231) ◽  
pp. 94-102 ◽  
Author(s):  
IULIAN-HORIA HOLOBÂCĂ
Keyword(s):  
Summer Temperature ◽  
Glacier Area ◽  
Regression Analyses ◽  
Positive Relation ◽  
Glacier Surface ◽  
Glacier System ◽  
Digital Elevation ◽  
Glacier Changes ◽  
Global Land ◽  
Increasing Trend

The glacier system covering Europe's highest mountain, Elbrus, has exhibited an accelerated retreat since 1980. Some studies have related this retreat to a significant summer temperature increasing trend. Relief- and aspect-related parameters for the glacierized area have an important impact on glacier changes. In this paper, the changes in glacier area are identified, quantified and correlated with relief parameters for the period 1985–2007. Spatial analysis was performed using the GLAM-CD (Glacier Mapper – Change Detector) algorithm. The input data for this algorithm were Landsat 5 images, the Aster Global Digital Elevation and the glacier outlines from the GLIMS project (Global Land Ice Measurements from Space). Regression analyses between glacier area losses and relief-related parameters indicate a significant positive relation with the altitude and a significant negative relation with the glacier surface area. In this context, we used a correlated component regression to model these relations. The model explains >50% of the total variation.

scholarly journals Quantifying changes and trends in glacier area and volume in the Austrian Ötztal Alps (1969-1997-2006)

2009 ◽  
Vol 3 (2) ◽  
pp. 205-215 ◽  
Author(s):  
J. Abermann ◽  
A. Lambrecht ◽  
A. Fischer ◽  
M. Kuhn
Keyword(s):  
Length Change ◽  
High Temporal Resolution ◽  
Glacier Area ◽  
Thickness Change ◽  
Additional Information ◽  
Digital Elevation ◽  
Glacier Changes ◽  
The Individual ◽  
Individual Size ◽  
Area And Volume

Abstract. In this study we apply a simple and reliable method to derive recent changes in glacier area and volume by taking advantage of high resolution LIDAR (light detection and ranging) DEMs (digital elevation models) from the year 2006. Together with two existing glacier inventories (1969 and 1997) the new dataset enables us to quantify area and volume changes over the past 37 years at three dates. This has been done for 81 glaciers (116 km2) in the Ötztal Alps which accounts for almost one third of Austria's glacier extent. Glacier area and volume have reduced drastically with significant differences within the individual size classes. Between 1997 and 2006 an overall area loss of 10.5 km2 or 8.2% occurred. Volume has reduced by 1.0 km3 which accounts for a mean thickness change of −8.2 m. The availability of three comparable inventories allows a comprehensive size and altitude dependent analysis of glacier changes but lacks a high temporal resolution. For the comparison of rates of changes between the two different periods (1969 to 1997 with 1997 to 2006) we propose two approaches in this study: a) to estimate mean overall rates of changes (including a period of advance) and b) to extract periods of net-retreat by using additional information (length change and mass balance measurements). Analysis of the resulting acceleration factors reveals that the retreat of volume and mean thickness changes has accelerated significantly more than that of area changes.

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