Ground ice conditions near Rea Point and on Sabine Peninsula, eastern Melville Island

1986 ◽  
Vol 23 (9) ◽  
pp. 1389-1400 ◽  
Author(s):  
H. M. French ◽  
L. Bennett ◽  
D. W. Hayley
Keyword(s):  
Late Winter ◽  
Ground Ice ◽  
Borehole Data ◽  
Site Specific ◽  
Ice Conditions ◽  
Ice Wedge ◽  
Ice Content ◽  
Using Data

Using data obtained in the winter of 1981–1982 from trench excavations in the vicinity of Rea Point, volumetric ice contents with depth have been calculated for Paleozoic age (Weatherall, Griper Bay, and Hecla Bay formations) and Quaternary age (alluvium and deltaic sands) sediments. In addition, borehole data from Sabine Peninsula and observations from the Panarctic Sherard Bay exploratory wellsite sump in the late winter of 1982–1983 enable similar values to be calculated for Mesozoic age (Christopher Formation) sediments. Although these data are believed typical of large areas of eastern Melville Island, they are only first estimates, since considerable site-specific variability may be present. Shale of the Christopher Formation possesses the highest ice content, typically between 30 and 70% by volume throughout the profile. Weatherall and Griper Bay siltstones and sandstones also contain locally significant ice contents (50–70%) at depths of 0.5–1.5 m. Pore and segregated ice are the dominant ice types. Ice-wedge ice is a relatively insignificant component of total ice content in any of the sediments examined.

Distribution and origin of ground ice in University Valley, McMurdo Dry Valleys, Antarctica

2016 ◽  
Vol 29 (2) ◽  
pp. 183-198 ◽  
Author(s):  
Caitlin Lapalme ◽  
Denis Lacelle ◽  
Wayne Pollard ◽  
David Fisher ◽  
Alfonso Davila ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Ground Surface ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Ground Ice ◽  
Permafrost Soils ◽  
Glacier Ice ◽  
Ice Conditions ◽  
Ice Content ◽  
Moisture Conditions

AbstractGround ice is one of the most important and dynamic geologic components of permafrost; however, few studies have investigated the distribution and origin of ground ice in the McMurdo Dry Valleys of Antarctica. In this study, ice-bearing permafrost cores were collected from 18 sites in University Valley, a small hanging glacial valley in the Quartermain Mountains. Ground ice was found to be ubiquitous in the upper 2 m of permafrost soils, with excess ice contents reaching 93%, but ground ice conditions were not homogeneous. Ground ice content was variable within polygons and along the valley floor, decreasing in the centres of polygons and increasing in the shoulders of polygons towards the mouth of the valley. Ground ice also had different origins: vapour deposition, freezing of partially evaporated snow meltwater and buried glacier ice. The variability in the distribution and origin of ground ice can be attributed to ground surface temperature and moisture conditions, which separate the valley into distinct zones. Ground ice of vapour-deposition origin was predominantly situated in perennially cryotic zones, whereas ground ice formed by the freezing of evaporated snow meltwater was predominantly found in seasonally non-cryotic zones.

Surficial materials and related ground ice conditions, Slave Province, N.W.T., Canada

1999 ◽  
Vol 36 (7) ◽  
pp. 1227-1238 ◽  
Author(s):  
Lynda A Dredge ◽  
Daniel E Kerr ◽  
Stephen A Wolfe
Keyword(s):  
Gulf Coast ◽  
Regional Scale ◽  
Coarse Grained ◽  
Silty Clay ◽  
Ground Ice ◽  
Wide Range ◽  
Ice Conditions ◽  
Western Arctic ◽  
Climatic History ◽  
Ice Content

Surficial mapping and geologic information on the nature and evolution of surficial materials in the Slave geologic province indicate that the geotechnical properties and potential ground ice contents associated with these materials depend largely upon their provenance, depositional conditions, and the postglacial climatic history. This information may be used to provide a regional-scale view of the distribution of ground ice conditions and terrain sensitivities associated with various surficial materials. In till veneers and blankets, ground ice content is generally low, as suggested by lack of thermokarst and other permafrost features. However, distinctive surface relief in hummocky till including kettle depressions, rim-ridges, and shallow thaw flowslides may be attributed to massive ice, resulting in sensitive till terrain. Although many outwash sediments have low ice contents near the surface, massive ice ranging from 5 to 10 m thick is present in some eskers and ice-contact outwash sediments. These are associated with thermokarst, slope movement, and collapse features, indicative of meltout or creep of large bodies of massive ice. The terrain sensitivity associated with these deposits is typically low to moderate, due to the coarse-grained nature of the sediments. In contrast, terrain sensitivity is high, and active-layer detachment slides are common along the Coronation Gulf coast where frozen silty clay marine sediments contain a wide range of ice contents. Results from this study may be applied to a much more extensive area of the glaciated western Arctic mainland and adjacent Arctic coastal plain in which materials with a similar glacial history are found.

Identifying ice-rich permafrost using remotely sensed late-season subsidence

2021 ◽  
Author(s):  
Simon Zwieback ◽  
Franz Meyer
Keyword(s):  
Critical Role ◽  
High Sensitivity ◽  
The Arctic ◽  
Ground Ice ◽  
Automated Mapping ◽  
Late Season ◽  
Warm Summer ◽  
Physically Based ◽  
Ice Wedge ◽  
Ice Content

<p>Despite the critical role of ground ice for permafrost ecosystems and terrain stability, we lack fine-scale ground ice maps across almost the entire Arctic. This is chiefly because ground ice cannot be observed directly from space. Here, we analyse late-season subsidence from Sentinel-1 InSAR satellite observations as a physically based indicator of vulnerable excess ground ice at the top of permafrost. The key idea is that the thaw front can penetrate materials that were previously perennially frozen at the end of a warm summer, triggering subsidence where the permafrost is ice rich. We assess the idea by comparing the InSAR observations to permafrost cores and an independently derived ground ice classification. </p><p>We find that the late-season subsidence in an exceptionally warm summer was 4 - 8 cm (5th - 95th percentile) in the ice-rich areas, while it was lower in ice-poor areas (-1 - 2 cm). The observed distributions for ice-rich and ice-poor terrain overlapped by only 2%, demonstrating high sensitivity and specificity for identifying top-of-permafrost excess ground ice. </p><p>The strengths of late-season subsidence include the ease of automation and its applicability to areas that lack conspicuous manifestations of ground ice, as often occurs on hillslopes. The biggest limitation is that it is not sensitive to excess ground ice below the thaw front and thus the total ice content. A further challenge is the sub-resolution variability in ground ice, ice-wedge polygons being a striking example, which needs to be accounted for when interpreting and validating the results.</p><p>We expect late-season subsidence to enhance the automated mapping of ice-rich permafrost terrain, complementing existing (predominantly non-automated) approaches based on largely indirect associations of ice content with vegetation and periglacial landforms. The suitability of satellite-observed late-season subsidence for mapping ice-rich permafrost can contribute to anticipating terrain instability in the Arctic and sustainably stewarding its ecosystems.</p>

Influence of ground ice and permafrost on coastal evolution, Richards Island, Beaufort Sea coast, N.W.T.

1996 ◽  
Vol 33 (5) ◽  
pp. 664-675 ◽  
Author(s):  
Scott R. Dallimore ◽  
Stephen A. Wolfe ◽  
Steven M. Solomon
Keyword(s):  
Coastal Erosion ◽  
Sediment Budget ◽  
Storm Event ◽  
Ground Ice ◽  
Coastal Evolution ◽  
Thermal Erosion ◽  
Ice Wedge ◽  
Mechanical Erosion ◽  
Sea Coast

A long-term sediment budget (1947−1985) for northern Richards Island shows that, when ground ice and offshore erosion are accounted for, there is a near balance between headland erosion and coastal deposition. Excess ice constitutes about 20% of the total volume of eroded material from the headlands, with massive ground ice contributing nearly 9% and segregated ice lenses and ice wedges making up the remainder. Coastal response to major storms in 1987 and 1993 suggests that erosion is episodic, with short periods of intense disruption followed by readjustment of cliff profiles. Processes characteristic of this environment include mechanical erosion of ice-bonded sediments creating unstable erosional niches, mechanical failure of niches along ice-wedge planes, and longer term thermal erosion of ice-bonded sediments. Where ice contents are high, localized thaw slumps initiated by coastal erosion may retreat at rates substantially higher than those observed at other sections of the coast. Cliff-top retreat rates may be out of phase with storm-event chronology.

scholarly journals Gravity Measurements in Permafrost Terrain Containing Massive Ground Ice

1983 ◽  
Vol 4 ◽  
pp. 133-140 ◽  
Author(s):  
K. Kawasaki ◽  
T. E. Osterkamp ◽  
R.W. Jurick ◽  
J. Kienle
Keyword(s):  
Limit Of Detection ◽  
Gravity Data ◽  
Soil Layer ◽  
Road Construction ◽  
Ground Truth ◽  
Ground Ice ◽  
Ground Truth Data ◽  
Gravity Measurements ◽  
Ice Content ◽  
Gravity Profile

Gravity measurements were made with a very sensitive gravimeter in permafrost terrain containing massive ground ice and other segregated ice. Measurements were first taken along a line over undisturbed terrain where a road cut was to be made; a second gravity profile parallel to the first profile but laterally displaced from it by about 36 m was subsequently made along the edge of the roadbed after road construction. Data from pre-construction borings and a profile of subsurface soil and ice conditions, synthesized from information obtained during cutting, were used for ground-truth information and compared with the gravity measurements. The horizontal dimensions and locations of the deposits of ground ice embedded in the soil layer correlated reasonably well with the dimensions and locations of the lows in the gravity profile. However, the second profile, taken along the roadbed, also showed significant variation even after the usual types of gravity corrections were applied, suggesting that there are significant horizontal variations in the density of the topmost layers of the underlying bedrock (schist) through which the cut was made. The density contrast of the undisturbed ice-rich soil as a function of distance along the first pro-file was estimated assuming the contrast was produced by infinitely long, transverse, rectangular blocks of given dimensions but unknown density. A set of equations dependent (to a first approximation) only on the unknown block densities was constructed from the corrected gravity data and solved by the Gauss-Seidel method. The maximum contrast for one block was found to be about 0.4 Mg m3 which gives a volumetric ice content of about 80% for the block, if the mean den-sity for all the blocks is taken to be 1.45 Mgg m3 A third gravity profile was made over an artificially-constructed ice mass with dimensions of 34 × 0.69 × 3.2 m buried at a depth of 1.2 m. This profile did not show conclusively the presence of the ice mass, partly because the anomaly it produces is close to the nominal limit of detection of the gravimeter. It is concluded that large massive ground ice can be detected by means of its gravitational field using sensitive commercially-available gravimeters in conjunction with some ground-truth data. However, the application of such gravimeters to routine pre-construction investigations and terrain reconnaissance for ground ice is limited by their sensitivity and by the requirement for a stable measuring platform. At present, the gravity method and possibly impulse radar are the only non-contacting remote methods for obtaining an estimate of the excess ice in permafrost.

Upscaling of geophysical measurements: A methodology for the estimation of the total ground ice content at two study sites in the dry Andes of Chile and Argentina

2020 ◽  
Author(s):  
Tamara Mathys ◽  
Christin Hilbich ◽  
Cassandra E.M. Koenig ◽  
Lukas Arenson ◽  
Christian Hauck
Keyword(s):  
Hydrological Cycle ◽  
Spatial Scales ◽  
Geophysical Methods ◽  
Central Andes ◽  
Permafrost Degradation ◽  
Rock Glacier ◽  
Ground Ice ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Ice Content

<p>With climate change and the associated continuing recession of glaciers, water security, especially in regions depending on the water supply from glaciers, is threatened. In this context, the understanding of permafrost distribution and its degradation is of increasing importance as it is currently debated whether ground ice can be considered as a significant water reservoir and as an alternative resource of fresh water that could potentially moderate water scarcity during dry seasons in the future. Thus, there is a pressing need to better understand how much water is stored as ground ice in areas with extensive permafrost occurrence and how meltwater from permafrost degradation may contribute to the hydrological cycle in the region.</p><p>Although permafrost and permafrost landforms in the Central Andes are considered to be abundant and well developed, the data is scarce and understanding of the Andean cryosphere lacking, especially in areas devoid of glaciers and rock glaciers.</p><p>In the absence of boreholes and test pits, geophysical investigations are a feasible and cost-effective technique to detect ground ice occurrences within a variety of landforms and substrates. In addition to the geophysical surveys themselves, upscaling techniques are needed to estimate ground ice content, and thereby future water resources, on larger spatial scales. To contribute to reducing the data scarcity regarding ground ice content in the Central Andes, this study focuses on the permafrost distribution and the ground ice content (and its water equivalent) of two catchments in the semi-arid Andes of Chile and Argentina. Geophysical methods (Electrical Resistivity Tomography, ERT and Refraction Seismic Tomography, RST) were used to detect and quantify ground ice in the study regions in the framework of environmental impact assessments in mining areas. Where available, ERT and RST measurements were quantitatively combined to estimate the volumetric ground ice content using the Four Phase Model (Hauck et al., 2011). Furthermore, we developed one of the first methodologies for the upscaling of these geophysical-based ground ice quantifications to an entire catchment in order to estimate the total ground ice volume in the study areas.</p><p>In this contribution we will present the geophysical data, the upscaling methodology used to estimate total ground ice content (and water equivalent) of permafrost areas, and some first estimates of total ground ice content in rock glacier and rock glacier free areas and compare them to conventional estimates using remotely sensed data.</p><p> </p><p>Hauck, C., Böttcher, M., and Maurer, H. (2011). A new model for estimating subsurface ice content based on combined electrical and seismic datasets, The Cryosphere, 5: 453-468.</p>

Sign in / Sign up

Export Citation Format

Share Document