scholarly journals Glacier shrinkage across High Mountain Asia

2016 ◽  
Vol 57 (71) ◽  
pp. 41-49 ◽  
Author(s):  
J. Graham Cogley
Keyword(s):  
Size Dependence ◽  
Time Span ◽  
High Mountain ◽  
Glacier Area ◽  
Glacier Inventory ◽  
Glacier Shrinkage ◽  
Rates Of Change ◽  
Spatial Coverage ◽  
Reduction Of Area ◽  
Geographical Grid

AbstractAn assessment of glacier shrinkage (reduction of area) for all of High Mountain Asia requires a complete compilation of measured rates of change and also a methodology for objective comparison of rates. I present a compilation from 155 publications reporting glacier area changes, and also a methodology that overcomes the main obstacles hindering comparison. Glacier areas are not always assigned uncertainties, and this problem is addressed with an error model derived from published estimates. The problem of discordant survey dates is addressed by interpolating measured areas to fixed dates at pentadal intervals. Interpolation error depends only incoherently on the time span between measurements, but strongly on glacier size: smaller glaciers, in addition to changing more rapidly on average, exhibit more variable rates of change. The overlapping boundaries of study regions are reconciled by mapping all of the information to a 0.5° geographical grid. When coupled with glacier area information from the Randolph Glacier Inventory, the widely observed inverse dependence of shrinkage rates on glacier size shows promise as a tool for treating incomplete spatial coverage. Over High Mountain Asia as a whole from 1960 to 2010, the unweighted average shrinkage rate is –0.57% a–1, but corrections for variable glacier size raise the average to –0.34% a–1, and filling unmeasured gridcells with rates based on size dependence alters the latter estimate to –0.40% a–1. The uncertainties in these rates are large. The Karakoram anomaly is found to be a zonal feature extending well to the east of the Karakoram proper.

scholarly journals Brief Communication: Updated GAMDAM Glacier Inventory over the High Mountain Asia

2018 ◽  
Author(s):  
Akiko Sakai
Keyword(s):  
Snow Cover ◽  
Cloud Cover ◽  
High Mountain ◽  
Glacier Area ◽  
Landsat Images ◽  
Glacier Inventory ◽  
Final Version ◽  
Seasonal Snow ◽  
Steep Slopes ◽  
Seasonal Snow Cover

Abstract. The first version of the Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM) glacier inventory was the first methodologically consistent glacier inventory covering High Mountain Asia, and it underestimated glacier area because it did not include steep slopes covered with ice or snow and shadowed areas. During the process of revising the GAMDAM glacier inventory, source Landsat images were carefully selected to find images free of shadows, cloud cover, and seasonal snow cover taken from 1990 to 2010. Then, more than 90 % of the glacier area in the final version of the GAMDAM glacier inventory was delineated based on summer Landsat images. The total glacier area was 100,693±15,103 km2 and included 134,770 glaciers using 453 Landsat image scenes.

scholarly journals Brief communication: Updated GAMDAM glacier inventory over high-mountain Asia

2019 ◽  
Vol 13 (7) ◽  
pp. 2043-2049 ◽  
Author(s):  
Akiko Sakai
Keyword(s):  
Snow Cover ◽  
Landsat Imagery ◽  
High Mountain ◽  
Glacier Area ◽  
Landsat Images ◽  
Glacier Inventory ◽  
Seasonal Snow ◽  
Seasonal Snow Cover

Abstract. The original Glacier Area Mapping for Discharge from the Asian Mountains (GAMDAM) glacier inventory was the first methodologically consistent dataset for high-mountain Asia. Nonetheless, the GAMDAM inventory underestimated glacier area, as it did not include steep ice- and snow-covered slopes or shaded components. During revision of the inventory, Landsat imagery free of shadow, cloud, and seasonal snow cover was selected for the period 1990–2010, after which >90 % of the glacier area was delineated. The updated GAMDAM inventory, comprised of 453 Landsat images, includes 134 770 glaciers with a total area of 100 693±11 790 km2.

scholarly journals LO STATO ATTUALE DEI GHIACCIAI ITALIANI E LA LORO RECENTE EVOLUZIONE

2020 ◽  
Author(s):  
Claudio Smiraglia ◽  
Guglielmina Adele Diolaiuti
Keyword(s):  
High Mountain ◽  
Glacier Area ◽  
Glacier Surface ◽  
Mountain Glacier ◽  
Glacier Inventory ◽  
Mountain Glaciers ◽  
Proglacial Lakes ◽  
The World ◽  
Mountain Landscapes ◽  
Recent Project

Mountain glaciers represent an important hydrological and touristic resource, and their recent evolution provides a dramatic evidence of climate change for the general public. Glacier inventories, quantifying glacier characteristics and evolution, are an important tool to describe and manage high mountain glacier environments and Italy has developed a long tradition in this sector. Our country was the first to provide itself with a glacier inventory, compiled by Comitato Glaciologico Italiano and CNR, showing a glacier surface of 530 km2. A recent project, coordinated by Università Statale di Milano with the support of private bodies and the cooperation of Comitato EvK2CNR and Comitato Glaciologico Italiano, led to the development of the new Italian Glacier Inventory, a national atlas produced from the analysis of color orthophotos at high resolution acquired between 2005 and 2011. The New Italian Glacier Inventory lists 903 glaciers, covering an area of 370 km2. The largest part of glacier area is located in Val d’Aosta (36.15% of the total), followed by Lombardia and South Tyrol. 84% of glaciers (considering the number of glaciers) have an area lower than 0.5 km2 and jointly account for 21% of the total glacier surface. Glaciers larger than 1 Km2 make up 9.4% of the total number, but cover 67.8% of the total glacier area. The comparison between data from the New Italian Glacier Inventory and the CGI-CNR inventory (1959-1962) shows a 30% reduction in glacier area in Italy; considering instead the World Glacier Inventory or WGI, published at the end of the ‘80s, which reported 1381 glaciers and an area of 609 km2, glacier loss sums up to 478 glaciers and an area of 239 km2 (-39%). This shrinkage has led to rapid and significant changes to high mountain landscapes, notably glacier fragmentation, an increase in deglaciated areas, the formation of proglacial lakes and the development of pioneer vegetation.

scholarly journals The GAMDAM glacier inventory: a quality-controlled inventory of Asian glaciers

2015 ◽  
Vol 9 (3) ◽  
pp. 849-864 ◽  
Author(s):  
T. Nuimura ◽  
A. Sakai ◽  
K. Taniguchi ◽  
H. Nagai ◽  
D. Lamsal ◽  
...  
Keyword(s):  
Peer Review ◽  
Landsat Imagery ◽  
The United States ◽  
United States Geological Survey ◽  
High Mountain ◽  
Data Sets ◽  
Glacier Area ◽  
Glacier Inventory ◽  
Elevation Model

Abstract. We present a new glacier inventory for high-mountain Asia named "Glacier Area Mapping for Discharge from the Asian Mountains" (GAMDAM). Glacier outlines were delineated manually using 356 Landsat ETM+ scenes in 226 path-row sets from the period 1999–2003, in conjunction with a digital elevation model (DEM) and high-resolution Google EarthTM imagery. Geolocations are largely consistent between the Landsat imagery and DEM due to systematic radiometric and geometric corrections made by the United States Geological Survey. We performed repeated delineation tests and peer review of glacier outlines in order to maintain the consistency and quality of the inventory. Our GAMDAM glacier inventory (GGI) includes 87 084 glaciers covering a total area of 91 263 ± 13 689 km2 throughout high-mountain Asia. In the Hindu Kush–Himalaya range, the total glacier area in our inventory is 93% that of the ICIMOD (International Centre for Integrated Mountain Development) inventory. Discrepancies between the two regional data sets are due mainly to the effects of glacier shading. In contrast, our inventory represents significantly less surface area (−24%) than the recent global Randolph Glacier Inventory, version 4.0 (RGI), which includes 119 863 ± 9201 km2 for the entirety of high Asian mountains. Likely causes of this disparity include headwall definition, effects of exclusion of shaded glacier areas, glacier recession since the 1970s, and inclusion of seasonal snow cover in the source data of the RGI, although it is difficult to evaluate such effects quantitatively. Further rigorous peer review of GGI will both improve the quality of glacier inventory in high-mountain Asia and provide new opportunities to study Asian glaciers.

scholarly journals First Glacier Inventory and Recent Changes in Glacier Area in the Monte San Lorenzo Region (47°S), Southern Patagonian Andes, South America

2013 ◽  
Vol 45 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Daniel Falaschi ◽  
Claudio Bravo ◽  
Mariano Masiokas ◽  
Ricardo Villalba ◽  
Andrés Rivera
Keyword(s):  
South America ◽  
Glacier Area ◽  
Glacier Inventory ◽  
San Lorenzo ◽  
Patagonian Andes

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 Inventory of glaciers in isla Riesco, Patagonia, Chile, based on aerial photography and satellite imagery

2002 ◽  
Vol 34 ◽  
pp. 373-378 ◽  
Author(s):  
Gino Casassa ◽  
Katrine Smith ◽  
Andrés Rivera ◽  
José Araos ◽  
Michael Schnirch ◽  
...  
Keyword(s):  
Supervised Classification ◽  
Satellite Image ◽  
Aerial Photographs ◽  
Glacier Area ◽  
Regional Warming ◽  
Glacier Inventory ◽  
Tm Image ◽  
Chilean Patagonia ◽  
Precipitation Decrease ◽  
Area Data

AbstractA glacier inventory for península Córdova, isla Riesco, Chilean Patagonia (53°14’ S, 73°00’W), has been compiled based on stereoscopic interpretation of aerial photographs of March and December 1984 and 1:100 000 topographic maps. Three small icefields comprising 33 glacier outlets, in addition to 12 small separate glaciers, have been identified, with a total area of 57 km2. Glaciers are located on mountain peaks with a maximum altitude of 1183 mand a lowermost elevation of 100 m. All glaciers terminate on land, except for three glaciers calving into small fresh-water lakes. A Landsat Thematic Mapper (TM) image of 6 October 1986 has been rectified and analyzed using a supervised classification to estimate snow- and glacier-covered surfaces. Glacier-area data derived from satellite-image analyses have been adjusted at península Córdova using photo-interpreted data, and extrapolated to estimate a glacier area of 215 ±40km2 for all of isla Riesco. The presence of trimlines and moraines beyond the present position of the glaciers indicates a generalized retreat from a maximum neoglacial position at península Córdova, most probably as a result of regional warming and precipitation decrease observed during the last century.

scholarly journals Mountain glaciers of southeast Siberia: current state and changes since the Little Ice Age

2014 ◽  
Vol 55 (66) ◽  
pp. 167-176 ◽  
Author(s):  
E.Yu. Osipov ◽  
O.P. Osipova
Keyword(s):  
Little Ice Age ◽  
Snow Accumulation ◽  
Ice Age ◽  
High Mountain ◽  
Late 20Th Century ◽  
Glacier Inventory ◽  
Mountain Glaciers ◽  
Current State ◽  
Field Investigations ◽  
Glacier Changes

AbstractContemporary glaciers of southeast Siberia are located on three high-mountain ridges (east Sayan, Baikalsky and Kodar). In this study, we present an updated glacier inventory based on high- to middle-resolution satellite imagery and field investigations. The inventory includes 51 glaciers with a total area of - 15 km2. Areas of individual glaciers vary from 0.06 to 1.33 km2, lengths from 130 to 2010 m and elevations from 1796 to 3490 m. The recent ice maximum extents (Little Ice Age) have been delineated from terminal moraines. On average, debris-free surface area shrunk by 59% between 1850 and 2006/11 (0.37% a–1), by 44% between 1850 and 2001/02 (0.29% a–1) and by 27% between 2001/02 and 2006/11 (3.39% a–1). The Kodar glaciers have experienced the largest area shrinkage, while the area loss on Baikalsky ridge was more moderate. Glacier changes are mainly related to regional summer temperature increase (by 1.7-2.6C from 1970 to 2010). There are some differences in glacier response due to different spatial patterns of snow accumulation, local topography (e.g. glacier elevation, slope) and geological activity. The studied glaciers (especially of Kodar ridge) are the most sensitive in Siberia to climate change since the late 20th century.

scholarly journals The status and decadal change of glaciers in Bhutan from the 1980s to 2010 based on satellite data

2014 ◽  
Vol 55 (66) ◽  
pp. 159-166 ◽  
Author(s):  
Samjwal Ratna Bajracharya ◽  
Sudan Bikash Maharjan ◽  
Finu Shrestha
Keyword(s):  
Land Cover ◽  
Image Classification ◽  
Satellite Data ◽  
Glacier Area ◽  
Decadal Change ◽  
Landsat Images ◽  
Equilibrium Line Altitude ◽  
Glacier Inventory ◽  
Object Based ◽  
The Status

AbstractIn order to monitor changes in the glaciers in the Bhutan Himalaya, a repeat decadal glacier inventory was carried out from Landsat images of 1977/78 (~1980), 1990, 2000 and 2010. The base map of glaciers was obtained by the object-based image classification method using the multispectral Landsat images of 2010. This method is used separately to delineate clean-ice and debris-covered glaciers with some manual editing. Glacier polygons of 2000,1990 and ~1980 were obtained by manual editing on 2010 by separately overlaying respective years. The 2010 inventory shows 885 glaciers with a total area of ~642 ± 16.1 km2. The glacier area is 1.6% of the total land cover in Bhutan. The result of a repeat inventory shows 23.3 ± 0.9% glacial area loss between ~1980 and 2010, with the highest loss (11.6 ±1.2%) between ~1980 and 1990 and the lowest (6.7 ±0.1%) between 2000 and 2010. The trend of glacier area change from the 1980s to 2010 is -6.4 ± 1.6%. Loss of glacier area was mostly observed below 5600 m a.s.l. and was greater for clean-ice glaciers. The equilibrium-line altitude has shifted upward from 5170 ± 110 m a.s.l. to 5350 ± 150 m a.s.l. in the years ~1980-2010.

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