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.

Physical and temporal factors controlling the development of near-surface ground ice at Illisarvik, western Arctic coast, Canada

2012 ◽  
Vol 49 (9) ◽  
pp. 1096-1110 ◽  
Author(s):  
H. Brendan O’Neill ◽  
C.R. Burn
Keyword(s):  
Important Variable ◽  
Lake Basin ◽  
Ground Ice ◽  
Near Surface ◽  
Marginal Areas ◽  
Permafrost Table ◽  
Western Arctic ◽  
Arctic Coast ◽  
Ice Content ◽  
Secondary Variable

Near-surface permafrost was sampled in summer 2010 at 26 sites in the Illisarvik drained-lake basin and nine sites in the surrounding tundra on Richards Island, NWT, to investigate the growth of segregated near-surface ground ice. Permafrost and ground ice have developed in the lake basin since drainage in 1978. The lake bed soils are predominantly silts of varying moisture and organic-matter contents, with sandier soils near the lake margins. Excess-ice contents in the basin were also variable, and ice enrichment was observed to a maximum depth of 60 cm below the 2010 permafrost table. Shrub-covered, wet areas had the highest mean excess-ice content in the top 50 cm of permafrost (10%), while grassy, dryer areas (4%) and poorly vegetated marginal areas (<1%) were less enriched with ice. Site wetness was the most important variable associated with near-surface excess-ice content in the lake basin. Silt content was a secondary variable. Mean excess-ice content in the top 50 cm of permafrost at tundra sites (25%) was much greater than in the basin, with ice enrichment to greater depths, likely a result of the time available for permafrost aggradation since the early Holocene climatic optimum.

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.

scholarly journals Internal structure of two alpine rockglaciers investigated by quasi-3D electrical resistivity imaging (ERI)

2016 ◽  
Author(s):  
Adrian Emmert ◽  
Christof Kneisel
Keyword(s):  
Electrical Resistivity ◽  
Internal Structure ◽  
Geophysical Methods ◽  
Swiss Alps ◽  
Electrical Resistivity Imaging ◽  
Active Layer Thickness ◽  
Ground Ice ◽  
Resistivity Imaging ◽  
Wide Range ◽  
Ice Content

Abstract. Interactions between different formative processes are reflected in the internal structure of rockglaciers. Its detection can therefore help to enhance our understanding of landform development. For an assessment of subsurface conditions, we present an analysis of the spatial variability of active layer thickness, ground ice content and frost table topography at two different rockglacier sites in the Eastern Swiss Alps by means of quasi-3D electrical resistivity imaging (ERI). This approach enables an extensive mapping of subsurface structures and hence the performance of a spatial overlay between site-specific surface und subsurface characteristics. At Nair rockglacier, we discovered a gradual descent of the frost table in a downslope direction and a homogenous decrease of ice content which follows the observed surface topography. This is attributed to ice formation by refreezing meltwater from an embedded snowbank or from a subsurface ice patch which reshapes the permafrost layer. The heterogeneous ground ice distribution at Uertsch rockglacier indicates that multiple processes on different time domains were involved in rockglacier development. Resistivity values which represent frozen conditions vary within a wide range and indicate a successive formation which includes several rockglacier advances, past glacial overrides and creep processes on the rockglacier surface. In combination with the observed rockglacier topography, quasi-3D ERI enables us to delimit areas of extensive and compressive flow in close proximity. Excellent data quality was provided by a good coupling of electrodes to the ground in the pebbly material of the investigated rockglaciers. Results show the value of the quasi-3D ERI approach but advice the application of complementary geophysical methods for interpreting the results.

scholarly journals Internal structure of two alpine rock glaciers investigated by quasi-3-D electrical resistivity imaging

2017 ◽  
Vol 11 (2) ◽  
pp. 841-855 ◽  
Author(s):  
Adrian Emmert ◽  
Christof Kneisel
Keyword(s):  
Electrical Resistivity ◽  
Internal Structure ◽  
Swiss Alps ◽  
Electrical Resistivity Imaging ◽  
Rock Glacier ◽  
Ground Ice ◽  
Resistivity Imaging ◽  
Wide Range ◽  
Rock Glaciers ◽  
Ice Content

Abstract. Interactions between different formative processes are reflected in the internal structure of rock glaciers. Therefore, the detection of subsurface conditions can help to enhance our understanding of landform development. For an assessment of subsurface conditions, we present an analysis of the spatial variability of active layer thickness, ground ice content and frost table topography for two different rock glaciers in the Eastern Swiss Alps by means of quasi-3-D electrical resistivity imaging (ERI). This approach enables an extensive mapping of subsurface structures and a spatial overlay between site-specific surface and subsurface characteristics. At Nair rock glacier, we discovered a gradual descent of the frost table in a downslope direction and a constant decrease of ice content which follows the observed surface topography. This is attributed to ice formation by refreezing meltwater from an embedded snow bank or from a subsurface ice patch which reshapes the permafrost layer. The heterogeneous ground ice distribution at Uertsch rock glacier indicates that multiple processes on different time domains were involved in the development. Resistivity values which represent frozen conditions vary within a wide range and indicate a successive formation which includes several advances, past glacial overrides and creep processes on the rock glacier surface. In combination with the observed topography, quasi-3-D ERI enables us to delimit areas of extensive and compressive flow in close proximity. Excellent data quality was provided by a good coupling of electrodes to the ground in the pebbly material of the investigated rock glaciers. Results show the value of the quasi-3-D ERI approach but advise the application of complementary geophysical methods for interpreting the results.

The Origin of Massive Icy Beds in Permafrost, Western Arctic Coast, Canada

1971 ◽  
Vol 8 (4) ◽  
pp. 397-422 ◽  
Author(s):  
J. Ross Mackay
Keyword(s):  
The Arctic ◽  
Ground Ice ◽  
Widespread Occurrence ◽  
Sea Floor ◽  
Western Arctic ◽  
Arctic Coast ◽  
Ice Content ◽  
Glacier Advance ◽  
Drill Holes ◽  
Level Lowering

Massive beds of ground ice are shown to exist along the arctic coastal plain east of the Alaska–Yukon boundary for a distance of at least 500 km. The massive ground ice can be seen in both undisturbed and glacially disturbed Pleistocene sediments. An examination of several thousand seismic shot hole logs, from drill holes of 15 to 35 m in depth, also corroborates the widespread occurrence of ground ice. The icy beds typically have an ice content, defined in terms of the weight of ice to dry soil, in excess of 200% for sections as much as 35 m thick. A theory is presented which suggests that: the ice is of segregation origin; the source of excess water was from the expulsion of ground water during the freezing of sands; and high pore water pressures, favorable to ice segregation, developed beneath an aggrading impermeable permafrost cover. Permafrost aggradation may have occurred either on an exposed sea floor during a period of sea level lowering which would have accompanied a glacier advance, or following a warm interval in which there had been deep thaw. Similarities in the origin of pingo ice and massive ice are discussed.

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.

Patterns in diversity and composition of the microbenthos of subarctic intertidal beaches with different morphodynamics

2020 ◽  
Vol 648 ◽  
pp. 19-38
Author(s):  
AI Azovsky ◽  
YA Mazei ◽  
MA Saburova ◽  
PV Sapozhnikov
Keyword(s):  
Species Abundance ◽  
Abundance Ratio ◽  
Wave Action ◽  
Coarse Grained ◽  
Sediment Properties ◽  
Β Diversity ◽  
Α Diversity ◽  
Wide Range ◽  
Similar Mode ◽  
Abundance And Diversity

Diversity and composition of benthic diatom algae and ciliates were studied at several beaches along the White and Barents seas: from highly exposed, reflective beaches with coarse-grained sands to sheltered, dissipative silty-sandy flats. For diatoms, the epipelic to epipsammic species abundance ratio was significantly correlated with the beach index and mean particle size, while neither α-diversity measures nor mean cell length were related to beach properties. In contrast, most of the characteristics of ciliate assemblages (diversity, total abundance and biomass, mean individual weight and percentage of karyorelictids) demonstrated a strong correlation to beach properties, remaining low at exposed beaches but increasing sharply in more sheltered conditions. β-diversity did not correlate with beach properties for either diatoms or ciliates. We suggest that wave action and sediment properties are the main drivers controlling the diversity and composition of the intertidal microbenthos. Diatoms and ciliates, however, demonstrated divergent response to these factors. Epipelic and epipsammic diatoms exhibited 2 different strategies to adapt to their environments and therefore were complementarily distributed along the environmental gradient and compensated for each other in diversity. Most ciliates demonstrated a similar mode of habitat selection but differed in their degree of tolerance. Euryporal (including mesoporal) species were relatively tolerant to wave action and therefore occurred under a wide range of beach conditions, though their abundance and diversity were highest in fine, relatively stable sediments on sheltered beaches, whereas the specific interstitial (i.e. genuine microporal) species were mostly restricted to only these habitats.

Assessment of the Role of Different Soil Properties on Crust Strength by Linear Regression Models

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
MINAKSHI SERAWAT ◽  
V K PHOGAT ◽  
ANIL Abdul KAPOOR ◽  
VIJAY KANT SINGH ◽  
ASHA SERAWAT
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Crop Yields ◽  
Modulus Of Rupture ◽  
Silty Clay ◽  
Linear Regression Models ◽  
Wide Range ◽  
Dispersion Ratio ◽  
Crust Strength

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.

scholarly journals Predictive modelling of soils’ hydraulic conductivity using artificial neural network and multiple linear regression

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Charles Gbenga Williams ◽  
Oluwapelumi O. Ojuri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Hydraulic Conductivity ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Coarse Grained ◽  
Soil Types ◽  
Wide Range ◽  
Artificial Neural ◽  
Input Variables

AbstractAs a result of heterogeneity nature of soils and variation in its hydraulic conductivity over several orders of magnitude for various soil types from fine-grained to coarse-grained soils, predictive methods to estimate hydraulic conductivity of soils from properties considered more easily obtainable have now been given an appropriate consideration. This study evaluates the performance of artificial neural network (ANN) being one of the popular computational intelligence techniques in predicting hydraulic conductivity of wide range of soil types and compared with the traditional multiple linear regression (MLR). ANN and MLR models were developed using six input variables. Results revealed that only three input variables were statistically significant in MLR model development. Performance evaluations of the developed models using determination coefficient and mean square error show that the prediction capability of ANN is far better than MLR. In addition, comparative study with available existing models shows that the developed ANN and MLR in this study performed relatively better.

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