scholarly journals Estimating Ice Thickness in South Georgia from SRTM Elevation Data

2012 ◽  
pp. 227-239
Author(s):  
A. Paul R. Cooper ◽  
James W. Tate ◽  
Alison J. Cook
Keyword(s):  
Ice Thickness ◽  
South Georgia ◽  
Elevation Data

scholarly journals Subglacial Morphology in Northern Palmer Land, Antarctic Peninsula

1981 ◽  
Vol 2 ◽  
pp. 17-22 ◽  
Author(s):  
R.D. Crabtree
Keyword(s):  
Antarctic Peninsula ◽  
Important Influence ◽  
Surface Elevation ◽  
Ice Thickness ◽  
Geological Evidence ◽  
Contour Maps ◽  
Divergent Flow ◽  
Elevation Data ◽  
Subglacial Topography ◽  
The Antarctic

Ice-thickness and surface-elevation data gathered from radio echo flights over the Antarctic Peninsula are presented as profiles for five major outlet glaciers in northern Palmer Land and as contour maps for an area of 8 000 km2 to the east of George VI Sound. Glacier profiles appear to be closely related to ice discharge especially to convergent and divergent flow. Comparison of subglacial topography with geological evidence of faulting suggests that the area around George VI Sound is a region where structure is an important influence on the pattern of glacial erosion.

What is a Glacier? Assessing Ice Dynamic Thresholds

2021 ◽  
Author(s):  
Caitlyn Florentine
Keyword(s):  
Science Communication ◽  
Stress Sensitivity ◽  
Ice Thickness ◽  
Median Surface ◽  
Policy Makers ◽  
Material Density ◽  
Elevation Data ◽  
Order Of Magnitude ◽  
Mapping Techniques ◽  
Thickness Measurements

<p>The current global Randolph Glacier Inventory (RGI V6) minimum area cutoff is 0.01 km<sup>2</sup>. Including features this small empowers comprehensive assessments of global glacier water resources. It also enables high-resolution glacier hindcasts, ensuring that sites where modern glacier extent is now diminutive are charted and not overlooked. Yet the automated and manual mapping techniques used to generate RGI glacier outlines do not necessarily discriminate based on ice motion. There is currently no RGI mask that discerns between glaciers that likely still deform under their own weight (classic glacier) versus glaciers that are unlikely to satisfy this criterion (stagnant ice patch). Here is a highly simplified, data-driven attempt to develop a globally complete ice dynamic mask. Features are treated as simple slabs, with area given by the RGI database, order of magnitude thickness derived from volume-area power law scaling, and median surface slope derived from topography data (RGI-TOPO dataset, beta release). Driving stress is calculated using these inputs and assuming material density 900 kg m<sup>-3</sup>. This is repeated using varying elevation data sources, the globally complete consensus ice thickness estimate, and sparse direct ice thickness measurements (GlaThiDa), to explore driving stress sensitivity to different slab representations. Slabs with driving stress less than 10<sup>5</sup> Pa are interpreted as features where the ambient driving stress is insufficient to overcome the yield strength of ice. Uncertainty analysis and comparison against ice motion observations determines if these sub 10<sup>5</sup> Pa slab features reliably mask RGI glaciers that are no longer in motion. This approach serves as a first cut at developing a reproducible, systematic way of discerning between classic glaciers (bodies of ice that move) versus other cryosphere features. This may enhance consistency across technical analyses within the glaciological research community and science communication with policy makers.</p>

scholarly journals A Survey of the Vanderford and Adams Glaciers in East Antarctica (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 197
Author(s):  
E R. Davis ◽  
D.J. Jones ◽  
V.I. Morgan ◽  
N.W. Young
Keyword(s):  
Austral Summer ◽  
Ice Thickness ◽  
The South ◽  
Data Logger ◽  
Gravity Measurements ◽  
Elevation Data ◽  
Glacier Flow ◽  
To Come ◽  
Navigation Equipment ◽  
Ice Radar

A comprehensive, airborne survey of the Vanderford and Adams glaciers was started in January 1983, continued through the austral summer season 1984/5, and completed in February 1985. Ice-thickness and surface-elevation data were collected over some 4500 square kilometres, on a grid spacing of approximately 5 kilometres. The measurement system was based on a Bell 206 helicopter, fitted with ANARE 100 MHz ice radar, Motorola Mini-Ranger navigation equipment, and a digital, pressure altimeter. A JMR, satellite, doppler receiver was used to position the navigation ground stations precisely. Gravity measurements were used to fill in ice-thickness coverage, where the ice radar failed to produce an echo and also to help determine where the glacier was floating. Ice-movement profiles were measured across the front sections of the glaciers and additional spot values were obtained further upstream by utilizing the 3 m accuracy of the navigation equipment to locate markers quickly at both the beginning and end of the season’s work. A data logger in the helicopter recorded time, navigation distances, aircraft to ground clearance, and air pressure, at 10 second intervals. These data were later merged with manually-scaled, ice-thickness values, for computer processing. The results show that the Vanderford glacier dominates the system and drains about 5 cubic kilometres of ice per annum, mainly from the inland ice sheet to the south. Ice flowing into the Adams Glacier tends to come from nearer the coast and to the south and west of the glacier. Bedrock topography beneath the Vanderford shows that the deep, inland trench, similar to that found below other outlet glaciers, drops to 2500 m below sea level, 60 kilometres from the front. The trench has steep sides to the east and gives a clearly-defined edge to the fast glacier flow. The western side, however, is much more complicated, particularly further inland, where the flow is not clearly separate from that of the Adams glacier.

scholarly journals A Survey of the Vanderford and Adams Glaciers in East Antarctica (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 197-197 ◽  
Author(s):  
E R. Davis ◽  
D.J. Jones ◽  
V.I. Morgan ◽  
N.W. Young
Keyword(s):  
Austral Summer ◽  
Ice Thickness ◽  
The South ◽  
Data Logger ◽  
Gravity Measurements ◽  
Elevation Data ◽  
Glacier Flow ◽  
To Come ◽  
Navigation Equipment ◽  
Ice Radar

A comprehensive, airborne survey of the Vanderford and Adams glaciers was started in January 1983, continued through the austral summer season 1984/5, and completed in February 1985.Ice-thickness and surface-elevation data were collected over some 4500 square kilometres, on a grid spacing of approximately 5 kilometres.The measurement system was based on a Bell 206 helicopter, fitted with ANARE 100 MHz ice radar, Motorola Mini-Ranger navigation equipment, and a digital, pressure altimeter. A JMR, satellite, doppler receiver was used to position the navigation ground stations precisely. Gravity measurements were used to fill in ice-thickness coverage, where the ice radar failed to produce an echo and also to help determine where the glacier was floating.Ice-movement profiles were measured across the front sections of the glaciers and additional spot values were obtained further upstream by utilizing the 3 m accuracy of the navigation equipment to locate markers quickly at both the beginning and end of the season’s work.A data logger in the helicopter recorded time, navigation distances, aircraft to ground clearance, and air pressure, at 10 second intervals. These data were later merged with manually-scaled, ice-thickness values, for computer processing.The results show that the Vanderford glacier dominates the system and drains about 5 cubic kilometres of ice per annum, mainly from the inland ice sheet to the south. Ice flowing into the Adams Glacier tends to come from nearer the coast and to the south and west of the glacier. Bedrock topography beneath the Vanderford shows that the deep, inland trench, similar to that found below other outlet glaciers, drops to 2500 m below sea level, 60 kilometres from the front. The trench has steep sides to the east and gives a clearly-defined edge to the fast glacier flow. The western side, however, is much more complicated, particularly further inland, where the flow is not clearly separate from that of the Adams glacier.

In-situ automatic observations of ice thickness of seas

2012 ◽  
Vol 19 (3) ◽  
pp. 583-592 ◽  
Author(s):  
Yinke Dou ◽  
Xiaomin Chang
Keyword(s):  
Sea Ice ◽  
New Technologies ◽  
Capacitive Sensor ◽  
Automatic Monitoring ◽  
Ice Thickness ◽  
In Situ Observation ◽  
Glacier Surface ◽  
Sea Ice Thickness ◽  
Surface Ice

Abstract Ice thickness is one of the most critical physical indicators in the ice science and engineering. It is therefore very necessary to develop in-situ automatic observation technologies of ice thickness. This paper proposes the principle of three new technologies of in-situ automatic observations of sea ice thickness and provides the findings of laboratory applications. The results show that the in-situ observation accuracy of the monitor apparatus based on the Magnetostrictive Delay Line (MDL) principle can reach ±2 mm, which has solved the “bottleneck” problem of restricting the fine development of a sea ice thermodynamic model, and the resistance accuracy of monitor apparatus with temperature gradient can reach the centimeter level and research the ice and snow substance balance by automatically measuring the glacier surface ice and snow change. The measurement accuracy of the capacitive sensor for ice thickness can also reach ±4 mm and the capacitive sensor is of the potential for automatic monitoring the water level under the ice and the ice formation and development process in water. Such three new technologies can meet different needs of fixed-point ice thickness observation and realize the simultaneous measurement in order to accurately judge the ice thickness.

Urban Flood Mapping

2017 ◽  
Author(s):  
Indra Riyanto ◽  
Lestari Margatama
Keyword(s):  
Natural Disasters ◽  
Satisfying Condition ◽  
Three Dimensions ◽  
Urban Flood ◽  
Digital Elevation ◽  
Elevation Data ◽  
Recent Occurrence ◽  
Elevation Model ◽  
Digital Elevation Model Data ◽  
Potential Area

The recent degradation of environment quality becomes the prime cause of the recent occurrence of natural disasters. It also contributes in the increase of the area that is prone to natural disasters. Flood history data in Jakarta shows that flood occurred mainly during rainy season around January – February each year, but the flood area varies each year. This research is intended to map the flood potential area in DKI Jakarta by segmenting the Digital Elevation Model data. The data used in this research is contour data obtained from DPP–DKI with the resolution of 1 m. The data processing involved in this research is extracting the surface elevation data from the DEM, overlaying the river map of Jakarta with the elevation data. Subsequently, the data is then segmented using watershed segmentation method. The concept of watersheds is based on visualizing an image in three dimensions: two spatial coordinates versus gray levels, in which there are two specific points; that are points belonging to a regional minimum and points at which a drop of water, if placed at the location of any of those points, would fall with certainty to a single minimum. For a particular regional minimum, the set of points satisfying the latter condition is called the catchments basin or watershed of that minimum, while the points satisfying condition form more than one minima are termed divide lines or watershed lines. The objective of this segmentation is to find the watershed lines of the DEM image. The expected result of the research is the flood potential area information, especially along the Ciliwung river in DKI Jakarta.

Sign in / Sign up

Export Citation Format

Share Document