scholarly journals A new glacier inventory for the Svartisen region, Norway, from Landsat ETM+ data: challenges and change assessment

2009 ◽  
Vol 55 (192) ◽  
pp. 607-618 ◽  
Author(s):  
Frank Paul ◽  
Liss M. Andreassen
Keyword(s):  
Topographic Map ◽  
Large Area ◽  
Study Region ◽  
Glacier Inventory ◽  
Northern Norway ◽  
Change Assessment ◽  
Hydropower Production ◽  
Snow Conditions ◽  
Key Indicators ◽  
Glacier Mapping

AbstractGlaciers are widely recognized as key indicators of climate change, and their meltwater plays an important role in hydropower production in Norway. Since the last glacier inventory was compiled in northern Norway in the 1970s, marked fluctuations in glacier length and mass balance have been reported for individual glaciers, and the current overall glacier state is thus not well known. Within the framework of the Global Land Ice Measurements from Space (GLIMS) initiative, we have created a new inventory for 489 glaciers in the Svartisen region, northern Norway, using a Landsat Enhanced Thematic Mapper Plus (ETM+) satellite scene from 7 September 1999 and automated multispectral glacier mapping (thresholded band ratios). In addition, visual inspection and correction of the generated glacier outlines has been applied. Adverse snow conditions and uncertain drainage divides made glacier mapping challenging in some regions of the study site. Glacier outlines from 1968, as digitized from a topographic map, were used for a quantitative change assessment for a selection of 300 glaciers. The overall area change of this sample from 1968 to 1999 was close to zero, but with a strongly increasing scatter towards smaller glaciers, large area gains (>50%) for small glaciers (<1 km2), and an unexpected stronger relative area loss towards the wetter coast. The overall size changes are small (<1%) for the three largest ice masses in the study region (Vestisen, Østisen and Blåmannsisen).

scholarly journals A new glacier inventory on southern Baffin Island, Canada, from ASTER data: I. Applied methods, challenges and solutions

2009 ◽  
Vol 50 (53) ◽  
pp. 11-21 ◽  
Author(s):  
Felix Svoboda ◽  
Frank Paul
Keyword(s):  
Climate Change Impacts ◽  
Ice Age ◽  
Baffin Island ◽  
Glacier Inventory ◽  
Ice Caps ◽  
Digital Elevation ◽  
Glacier Length ◽  
Length And Area ◽  
Shortwave Infrared ◽  
Glacier Mapping

AbstractThe quantitative assessment of glacier changes as well as improved modeling of climate-change impacts on glaciers requires digital vector outlines of individual glacier entities. Unfortunately, such a glacier inventory is still lacking in many remote but extensively glacierized gions such as the Canadian Arctic. Multispectral satellite data in combination with digital elevation models (DEMs) a particularly useful for creating detailed glacier inventory data including topographic information for each entity. In this study, we extracted glacier outlines and a DEM using two adjacent Terra ASTER scenes acquired in August 2000 for a remote region on southern Baffin Island, Canada. Additionally, Little Ice Age (LIA) extents we digitized from trimlines and moraines visible on the ASTER scenes, and Landsat MSS and TM scenes from the years 1975 and 1990 we used to assess changes in glacier length and area. Because automated delineation of glaciers is based on a band in the shortwave infrared, we have developed a new semi-automated glacier-mapping approach for the MSS sensor. Wrongly classified debris-coved glaciers, water bodies and attached snowfields we corrected manually for both ASTER and MSS. Glacier drainage divides we manually digitized by combining visual interptation with DEM information. In this first paper, we describe the applied methods for glacier mapping and the glaciological challenges encounted (e.g. data voids, snow cover, ice caps, tributaries), while the second paper ports the data analyses and the derived changes.

scholarly journals Glacier Mapping for an Inventory of the Indus Drainage Basin: Current State and Future Possibilities

1986 ◽  
Vol 8 ◽  
pp. 102-105
Author(s):  
W. Kick
Keyword(s):  
Drainage Basin ◽  
Landsat Imagery ◽  
Reliable Data ◽  
Large Problem ◽  
Good Opportunity ◽  
Glacier Inventory ◽  
Current State ◽  
The World ◽  
Glacier Mapping

A large problem of the World Glacier Inventory is the Pakistan part which is still missing. The available official quarter-inch and half-inch maps of the Survey of India and Pakistan are not adequate for the purpose. The maps of some expeditions provide reliable data for a few areas. Landsat imagery does not yield heights and has other disadvantages. At the present time, the Spacelab mission, in September 1986, with its metric camera, seems to offer a rather good opportunity.

scholarly journals A new glacier inventory on southern Baffin Island, Canada, from ASTER data: II. Data analysis, glacier change and applications

2009 ◽  
Vol 50 (53) ◽  
pp. 22-31 ◽  
Author(s):  
Frank Paul ◽  
Felix Svoboda
Keyword(s):  
Strong Dependence ◽  
Baffin Island ◽  
Automated Classification ◽  
Inventory Data ◽  
Large Area ◽  
Glacier Inventory ◽  
Ice Caps ◽  
Digital Elevation ◽  
Elevation Model ◽  
Remote Sensing Methods

AbstractDespite its large area covered by glaciers and ice caps, detailed glacier inventory data are not yet available for most parts of Baffin Island, Canada. Automated classification of satellite data could help to overcome the data gaps. Along-track stereo sensors allow the derivation of a digital elevation model (DEM) and glacier outlines from the same point in time, and are particularly useful for this task. While part I of this study describes the remote-sensing methods, in part II we present an analysis of the derived glacier inventory data for 662 glaciers and an application to glacier volume and volume-change calculations. Among other things, the analysis reveals a mean glacier elevation of 990 m, with a weak dependence on aspect and a close agreement of the arithmetic mean with the statistical mean elevation as derived from the DEM. A strong scatter of mean slope is observed for glaciers <1 km2, and the derived glacier thickness differs by a factor of two for glaciers of the same size. For the period from about 1920 to 2000 the relative area change is –12.5% (264 glaciers), with a strong dependence on glacier size. Mean mass loss as derived from volume changes is about –0.15 mw.e. a–1.

scholarly journals A new glacier inventory for the Jostedalsbreen region, Norway, from Landsat TM scenes of 2006 and changes since 1966

2011 ◽  
Vol 52 (59) ◽  
pp. 153-162 ◽  
Author(s):  
Frank Paul ◽  
Liss M. Andreassen ◽  
Solveig H. Winsvold
Keyword(s):  
Field Measurements ◽  
Glacier Inventory ◽  
Digital Elevation ◽  
Cumulative Length ◽  
Length Changes ◽  
Snow Conditions ◽  
The 1960S ◽  
Elevation Model ◽  
Good Agreement ◽  
Area Determination

AbstractPronounced changes in glacier mass and length were observed for the monitored glaciers in the Jostedalsbreen region, Norway, since the last glacier inventories were compiled in the 1960s and 1980s. However, the current overall extent of the glaciers in the region is not well known. To obtain this information, we have compiled a new inventory from two mosaicked Landsat Thematic Mapper (TM) scenes acquired in 2006 that have excellent snow conditions for glacier mapping, the first suitable scenes for this purpose after 22 years of imaging with TM. Drainage divides and topographic inventory parameters were derived from a 25 m national digital elevation model for 1450 glaciers. By digitizing glacier outlines from 1 : 50 000 scale topographic maps of 1966, we calculated changes in glacier area for ~300 glaciers. Cumulative length changes for the 1997–2006 period were derived from an additional TM scene and compared with field measurements for nine glaciers. Overall, we find a 9% area loss since 1966, with a clear dependence on glacier size; however, seasonal snow in 1966 in some regions made area determination challenging. The satellite-derived length changes confirmed the observed high spatial variability and were in good agreement with field data (±1 pixel), apart from glacier tongues in cast shadow. The new inventory will be freely available from the Global Land Ice Measurements from Space (GLIMS) glacier database.

scholarly journals In the eye of the storm

2021 ◽  
Author(s):  
Edward J. Walsh ◽  
C. W. Fairall ◽  
Ivan PopStefanija
Keyword(s):  
Real Time ◽  
Wave Height ◽  
Secondary Wave ◽  
Wave Spectra ◽  
Topographic Map ◽  
Radar Altimeter ◽  
Large Area ◽  
Ground Station ◽  
Data Products ◽  
Wave Models

AbstractThe airborne NOAA Wide Swath Radar Altimeter (WSRA) is a 16 GHz digital beamforming radar altimeter that produces a topographic map of the waves as the aircraft advances. The wave topography is transformed by a two-dimensional FFT into directional wave spectra. The WSRA operates unattended on the aircraft and provides continuous real-time reporting of several data products: (1) significant wave height, (2) directional ocean wave spectra, (3) the wave height, wavelength, and direction of propagation of the primary and secondary wave fields, (4) rainfall rate and (5) sea surface mean square slope (mss). During hurricane flights the data products are transmitted in real-time from the NOAA WP-3D aircraft through a satellite data link to a ground station and on to the National Hurricane Center (NHC) for use by the forecasters for intensity projections and incorporation in hurricane wave models. The WSRA is the only instrument that can quickly provide high-density measurements of the complex wave topography over a large area surrounding the eye of the storm.

scholarly journals Glacier variations in the Himalaya from 1990 to 2015 based on remote sensing

2020 ◽  
Author(s):  
Qin Ji ◽  
Jun Dong ◽  
Hong-rong Li ◽  
Yan Qin ◽  
Rui Liu ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Large Area ◽  
Glacier Inventory ◽  
The North ◽  
South Slope ◽  
Monsoon System ◽  
The Himalaya ◽  
Continental Climate

Abstract. The Himalaya is located in the southwest margin of the Tibetan Plateau. The region is of special interest for glacio-climatological research as it is influenced by both the continental climate of Central Asia and The Indian Monsoon system. Despite its large area covered by glaciers, detail glacier inventory data are not yet available for the entire Himalaya. The study presents spatial patterns in glacier area in the entire Himalaya are multiple spatial scales. We combined Landsat TM/ETM+/OLI from 1990 to 2015 and ASTER GEDM (30 m). In the years around 1990 the whole mountain range contained about 12211 glaciers covering an area of 23229.27 km2, while the ice on south slope covered 14451.25 km2. Glaciers are mainly distributed in the western of the Himalaya with an area of 11551.69 km2 and the minimum is the eastern. The elevation of glacier mainly distributed at 4,800∼6,200 m a.s.l. with an area percent of approximately 84 % in 1990. The largest number and ice cover of glaciers is hanging glacier and valley glacier, respectively. The number of debris-covered glaciers is relatively small, whereas covers an area of about 44.21 % in 1990. The glacier decreased by 10.99 % and this recession has accelerated from 1990 to 2015. The average annual shrinkage rate of the glaciers on the north slope (0.54 % a−1) is greater than that on the south slope (0.38 % a−1). Glacier decreased in the debris-covered glaciers and debris-free glaciers, and the area loss for the first is about 15.56 % and 5.22 % for the latter during 1990–2015, which showed that the moraine in the Himalaya can inhibit the ablation of glaciers to some extent.

Factors affecting distribution of landslides along rivers in southern Alberta

1977 ◽  
Vol 14 (4) ◽  
pp. 508-523 ◽  
Author(s):  
S. Thomson ◽  
N. R. Morgenstern
Keyword(s):  
Regional Study ◽  
Large Area ◽  
Study Region ◽  
Factors Affecting ◽  
Landslide Activity ◽  
Valley Slope ◽  
Southern Alberta ◽  
Geologic Maps ◽  
Meander Bends ◽  
Insight Into

A regional study of the distribution and characteristics of landslides along four major rivers in southern Alberta was undertaken in order to relate landslide activity to geologic and physiographic factors such as bedrock outcrop, groundwater, river sinuosity, and the aspect of valley slope. This provides greater insight into the factors controlling slides in the study region, particularly in the Cretaceous bedrock.The study was based on an analysis of air photos, augmented by surficial and bedrock geologic maps and hydrogeologic and bedrock topographic maps. The area is underlain by a thick sequence of gently dipping sedimentary strata of Upper Cretaceous age. Late Pleistocene glaciation deranged the drainage to some extent and the rivers studied now occupy postglacial channels in some reaches and are re-excavating preglacial channels in other reaches.The results of the study indicate that the bedrock type is of considerable importance since there is marked difference in valley wall stability between relatively unstable marine formations and the relatively stable nonmarine formations. Areas of comparatively high groundwater exert an obvious influence on landsliding. The importance of buried valleys in locally drawing down the water table is clearly evident. More than 90% of the landslides occur in meander bends and are related to river erosion.Failures in the bedrock appear to be translational whereas those higher on the valley wall in Pleistocene sediments are largely rotational. The data have been assembled on a profile of the river and present a regional picture of landslide activity over a large area.

Which DEM to use for glacier inventory applications? The example of Svalbard

2020 ◽  
Author(s):  
Philipp Rastner ◽  
Frank Paul
Keyword(s):  
Arctic Region ◽  
The Arctic ◽  
Minor Role ◽  
Large Area ◽  
Glacier Inventory ◽  
Ice Caps ◽  
Topographic Information ◽  
Digital Elevation ◽  
Elevation Model ◽  
A Minor

&lt;p&gt;Creating glacier inventories from satellite images and a digital elevation model (DEM) has become quasi standard. Besides the specific challenges for glacier mapping, also the selection of the &amp;#8216;best&amp;#8217; DEM can be difficult. When using it to derive surface drainage divides and topographic information for each glacier, one has to consider the date of acquisition, artefacts, spatial completeness (data voids) and resolution. In general, using different DEMs gives different drainage divides and thus other glacier sizes. Moreover, due to widespread glacier retreat and rapid surface lowering, topographic information from older DEMs is increasingly biased towards too high values.&lt;/p&gt;&lt;p&gt;In this study we analyse seven freely available DEMs for the Arctic region of Svalbard: ALOS AW3D30, two National Elevation Datasets (NEDs), Arctic DEM, TanDEM-X (90 and 30 m products) and the ASTER GDEM2. All individual DEM tiles were mosaicked and re-projected bilinearly to UTM 33 N. Comparisons of topographic data are performed for three test regions: a) stable terrain (off glaciers), b) glaciers in rough topography, and c) flat glaciers and ice caps.&lt;/p&gt;&lt;p&gt;Overlay of drainage divides indicate large area differences on flat ice caps and small ones in rough topography, where mountain ridges are distinct. On the other hand, different spatial resolution results in large differences in rough topography but plays only a minor role for flat topography. Only 2 m elevation differences on stable terrain in flat valley bottoms were detected between the ALOS DEM (79.9m) and the two NEDs (77.9 m). No differences were found between the TanDEM-X 90 / 30 m and the Arctic DEM (all 109. 9 m). The ellipsoid-geoid difference is thus ~30 m in this region.&lt;/p&gt;&lt;p&gt;Mean elevations of glaciers with flat topography or ice caps differ only slightly, but in steeper topography they reach 6 to 8 m. These differences are also due to the different resolution of the DEMs. In all test regions, only small gaps are detected in the Arctic DEM and artefacts are especially present in the ALOS DEM. For this region the &amp;#8216;best&amp;#8217; DEM is the TanDEM-X DEM.&lt;/p&gt;

scholarly journals Glacier Mapping for an Inventory of the Indus Drainage Basin: Current State and Future Possibilities

1986 ◽  
Vol 8 ◽  
pp. 102-105 ◽  
Author(s):  
W. Kick
Keyword(s):  
Drainage Basin ◽  
Landsat Imagery ◽  
Reliable Data ◽  
Large Problem ◽  
Good Opportunity ◽  
Glacier Inventory ◽  
Current State ◽  
The World ◽  
Glacier Mapping

A large problem of the World Glacier Inventory is the Pakistan part which is still missing. The available official quarter-inch and half-inch maps of the Survey of India and Pakistan are not adequate for the purpose. The maps of some expeditions provide reliable data for a few areas. Landsat imagery does not yield heights and has other disadvantages. At the present time, the Spacelab mission, in September 1986, with its metric camera, seems to offer a rather good opportunity.

scholarly journals Glacier Inventory of James Ross and Vega Islands, Antarctic Peninsula

1982 ◽  
Vol 3 ◽  
pp. 260-264 ◽  
Author(s):  
Jorge Rabassa ◽  
Pedro Skvarca ◽  
Luis Bertani ◽  
Elizabeth Mazzoni
Keyword(s):  
Antarctic Peninsula ◽  
Topographic Map ◽  
Glacier Inventory ◽  
The World

This paper presents the results of the glacier Inventory of James Ross and Vega islands based on topographic map sheets at 1:250 000 scale, Landsat multi-spectral scanner imagery in bands 4 and 7 at the same scale, and oblique air photographs obtained in 1979–80. Work was completed following the methodology proposed by the Temporary Technical Secretariat of the World Glacier Inventory. This is the first such inventory carried out in Antarctica.

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