Reticulate Ice Veins in Permafrost, Northern Canada

1974 ◽  
Vol 11 (2) ◽  
pp. 230-237 ◽  
Author(s):  
J. Ross Mackay
Keyword(s):  
Three Dimensional ◽  
Drill Hole ◽  
Field Observations ◽  
Upward Migration ◽  
Northern Canada ◽  
Shrinkage Cracks ◽  
Thaw Consolidation ◽  
Ice Content ◽  
Glacial Tills ◽  
Marine Clays

A reticulate ice vein network is of common occurrence in many lake and marine clays, glacial tills, and mudflow deposits in permafrost areas of northern Canada. The ice vein network may grade downward into high ice content soils at depth. Field observations suggest that the reticulate ice veins grew in vertical and horizontal shrinkage cracks, with much of the water being derived from the adjacent clay, in a semiclosed freezing system, rather than from an upward migration of water in an open system. The three-dimensional geometry of the ice vein network is a factor to be considered in drill hole sampling, thaw–consolidation studies, and differential settlement estimates.

Dikes on permafrost foundations in northern Manitoba

1970 ◽  
Vol 7 (4) ◽  
pp. 356-364 ◽  
Author(s):  
J. G. Macpherson ◽  
G. H. Watson ◽  
A. Koropatnick
Keyword(s):  
Electric Power ◽  
Heat Loss ◽  
Free Water ◽  
Northern Canada ◽  
Discontinuous Permafrost ◽  
Ice Content ◽  
The Relationship ◽  
Design And Construction

The development of hydro-electric power within the areas of low relief of northern Canada often requires long dikes to impound a reservoir. Much of this region lies within a zone of discontinuous permafrost, and dike design must allow for foundations varying from soft alluvial materials which will settle during or shortly after construction, to frozen strata with a high ice content which will settle as the ice thaws due to heat loss from the reservoir.This paper describes the approach to design and construction of dikes for the Kettle Generating Station in northern Manitoba, and includes a description of the instrumentation installed in an attempt to correlate the relationship between the rate of thawing of the permafrost and the rate of drainage of free water from the foundation.

Modern techniques in illustration and recording in geology

2019 ◽  
pp. 267-282
Author(s):  
Matthew J. Genge
Keyword(s):  
Field Data ◽  
Earth Science ◽  
Three Dimensional ◽  
Field Observations ◽  
Valuable Data ◽  
New Methods ◽  
Geological Features ◽  
Field Notes ◽  
Digital Methods ◽  
Three Dimensional Models

Advances in technology have enabled new methods in the acquisition and recording of field data in geology and its presentation within publications. These techniques compliment, rather than replace, traditional field observations. This chapter describes the use of photogrammetry and aerial drone surveys in constructing three-dimensional models of geological features, which provide valuable data when combined with field notes on lithology. Digital methods in the analysis and processing of images are discussed together with methods in digital drawing and painting to produce publication-ready diagrams for Earth Science. Photographs for use in publications should be corrected to ensure optimal contrast and brightness.

scholarly journals 3D Printed Personalized Guide Plate in the Femoral Head Core Decompression

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Liangliang Cheng ◽  
Xing Qiu ◽  
Lei Yang ◽  
Chi Xiao ◽  
Baoyi Liu ◽  
...  
Keyword(s):  
Femoral Head ◽  
Three Dimensional ◽  
Core Decompression ◽  
Operation Time ◽  
Drill Hole ◽  
Needle Insertion ◽  
Pathological Examination ◽  
Anatomic Structure ◽  
Guide Plate ◽  
3D Printed

Objective. To investigate the feasibility of using 3D printed personalized guide plates in core decompression procedures for the treatment of osteonecrosis of the femoral head (ONFH). Methods. The clinical data of 8 patients undergoing femoral head core decompression from January to December 2019 were analyzed retrospectively. Three-dimensional (3D) images of the patients were reconstructed from the CT scan data taken preoperatively. From the data obtained, puncture position, drill hole, and depth were evaluated, and individualized 3D puncture guide plates were designed using Mimics 21.0 software. During the operation, the needle went through the hole of the guide plate, the depth of the drill was controlled, and the obtained bone tissues were sent for pathological evaluation. Intraoperative X-ray and postoperative pathological results were used to evaluate the success of the puncture. Results. The individualized guide plates used for core compression on the 8 patients were well fitted with the anatomic structure of the puncture site, and the direction and depth of the needle insertion were consistent with the preoperative design. The operation time was about 15-22 mins. The position of the decompression tunnel was the same as the designed plate. The postoperative pathology showed necrotic bone tissue. There were no postoperative complications such as infection, bleeding, and fracture. Conclusion. The 3D printed individualized guide plate can simplify core decompression and would make this procedure more accurate, safe, and quick, in addition to obtaining necrotic tissues for pathological examination.

A three-dimensional model to simulate joint networks in layered rocks

2002 ◽  
Vol 39 (10) ◽  
pp. 1443-1455 ◽  
Author(s):  
Jean-Yves Josnin ◽  
Hervé Jourde ◽  
Pascal Fénart ◽  
Pascal Bidaux
Keyword(s):  
Fractured Rock ◽  
Fractured Reservoirs ◽  
Three Dimensional ◽  
Geometrical Parameters ◽  
Field Observations ◽  
Three Dimensional Model ◽  
Statistical Parameters ◽  
Joint Spacing ◽  
Fractal Approach ◽  
Geometrical Properties

Modelling the discontinuity network of fractured reservoirs may be addressed (1) by purely stochastic means, (2) with a fractal approach, or (3) using mechanical parameters describing the spatial organisation of fracture systems. Our paper presents an approach where the geometrical properties of the fracture networks are incorporated in the form of both statistical and mechanical rules. This type of approach is particularly suitable to model stratified fractured rock masses comprising two orthogonal families of joints and a family of sedimentary discontinuities. Their geometrical arrangement is governed by two kinds of rules based on (1) statistical parameters such as the mean, standard deviation of joint length and of bed thickness, both determined by field observations, and (2) geometrical parameters that result from genetic processes inferred from field observations and analogue experiments on the nucleation and propagation mechanisms of joints. Using these parameters, we generate realistic networks in terms of the relative position of joints that control the overall network connectivity: the model enables all combinations of joint spacing and vertical persistence for orthogonal patterns ranging from ladder type to grid type patterns. It also integrates the concept of mechanical "saturation" of a bed, thereby permitting the generation of both "saturated" and "unsaturated" networks.

scholarly journals FIELD OBSERVATIONS ON THE THREE-DIMENSIONAL STRUCTURE OF WIND-DRIVEN CURRENTS WITH SECONDARY CIRCULATIONS

2012 ◽  
Vol 68 (4) ◽  
pp. I_799-I_804
Author(s):  
Kouji IDE ◽  
Seiya HONMA ◽  
Yousuke ARAKI ◽  
Masaya HORIGUCHI ◽  
Ken-ichi UZAKI
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Field Observations ◽  
Three Dimensional Structure ◽  
Secondary Circulations ◽  
Wind Driven Currents

scholarly journals Frost boils and soil ice content: field observations

2006 ◽  
Vol 17 (4) ◽  
pp. 291-307 ◽  
Author(s):  
P. P. Overduin ◽  
D. L. Kane
Keyword(s):  
Field Observations ◽  
Ice Content ◽  
Soil Ice Content

scholarly journals Regional stagnation of the western Keewatin ice sheet and the significance of meltwater corridors and eskers, northern Canada

2021 ◽  
Author(s):  
David Sharpe ◽  
Jerome Lesemann ◽  
Ross Knight ◽  
Bruce Kjarsgaard
Keyword(s):  
Surface Modification ◽  
Land Surface ◽  
Regional Scale ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Field Observations ◽  
Remotely Sensed Data ◽  
Northern Canada ◽  
Significant Events ◽  
Patterns And Processes

The glacial landsystem of western Keewatin region, northern Canada, consists of three significant events. First, was regional emplacement of subglacial sediments, mainly till (a pre-existing landscape). Second, was regional-scale erosion (land surface modification) leading to development of an integrated, anabranched network of meltwater drainage routes producing meltwater corridors. Third, was deposition of an extensive array of eskers, and related forms, within meltwater corridors. Integration of field observations, mapping and remotely-sensed data allow us to link scoured bedrock and till surfaces, truncated drumlins, scour pits, glaciofluvial terraces, boulder lags, and the extensive network of erosional corridors, as part of regional meltwater erosion events. The network of long (~100-200 km), relatively wide (~1-3 km) meltwater corridors record confined subglacial erosion that scoured sediment (and bedrock) prior to glaciofluvial sedimentation (predominately eskers). Despite considerable sediment erosion along corridors, moraines and other ice-marginal deposits are rare on the western Keewatin landscape. The absence of these features is inconsistent with deglacial models relying on step-wise active retreat of the ice-margin. Instead, we propose that deglaciation of the western Keewatin Sector of the Laurentide Ice Sheet (LIS) was controlled by regional thinning and stagnation. These findings raise fundamental questions about deglacial patterns and processes and thus suggest that further evaluation and revision of existing models of deglacial chronology for this sector of the LIS is needed..

PROBLEMS OF DESIGNING SAFETY ZONES FOR PEOPLE WITH LIMITED MOBILITY

2021 ◽  
Vol 112 ◽  
pp. 103-108
Author(s):  
E.A. Bakulenko ◽  
◽  
A.P. Parfenenko
Keyword(s):  
Three Dimensional ◽  
Field Observations ◽  
Rehabilitation Center ◽  
Regulatory Requirements ◽  
Evacuation Time ◽  
Limited Mobility ◽  
Number Of Patients ◽  
Software Product ◽  
Reduced Mobility ◽  
Three Sisters

The article discusses the regulatory requirements for security zones, especially for the calculation of its area. Using the example of the Three Sisters rehabilitation center, located in the Moscow region, the actual required area of the security zone required for one person of the M4 population with limited mobility is considered. The number of patients with reduced mobility in rehabilitation insti-tutions exceeds at least twice. The evacuation of the M1-M3 mobility groups is considered via stairwells directly to the outside. Fullscale observations of the evacuation of people along horizontal paths to the safety zones were carried out to establish the evacuation time and the capacity of the safety zones. In the Pathfinder software product, a three-dimensional computer model of the buildings of the protection object was developed, taking into account the data obtained from field observations to assess the safe evacuation of people.

Geology, mineralogy, and geochemistry of Canadian soft soils: a geotechnical perspective

1980 ◽  
Vol 17 (2) ◽  
pp. 261-285 ◽  
Author(s):  
Robert M. Quigley
Keyword(s):  
Soft Soil ◽  
Three Dimensional ◽  
Research Literature ◽  
Low Density ◽  
Soft Soils ◽  
Soft Clays ◽  
Clay Deposits ◽  
Soil Sensitivity ◽  
Dimensional Distribution ◽  
Marine Clays

A review of the recent research literature concerning the geology, mineralogy, and physicochemistry of soft soils in Canada is presented. Soft clays are considered from three viewpoints: (1) their three-dimensional distribution and chronological evolution, (2) the sedimentological processes critical in their formation, and (3) geochemistry and mineralogy as they directly influence geotechnical behaviour, especially soft soil sensitivity.Canada's soft soils are products of sedimentation in proglacial and postglacial lake basins that existed between 18 000 and 6000 years BP. They consist of both freshwater and marine clays, which usually behave quite differently, due to peptization or dispersion of the marine clays following postglacial crustal rebound that elevated all clay deposits. The evolution of the major lakes and seas is briefly reviewed in a Canada-wide context.The sedimentology review shows clearly that varved clays are normally features of bottom, heavy-density turbidity current origin, probably in very cold, ice-contact glacial lakes. Warmer postglacial lakes were probably characterized by low-density overflows, and thinly laminated clay deposits developed rather than varved clay sequences. Marine clay deposits also developed from low-density freshwater overflows followed by flocculation, organic agglomeration, and sedimentation. Modern examples are given to illustrate the three major sedimentological processes.Mineralogy and physicochemistry are reviewed in terms of their practical relevance to soft soil sensitivity. Factors influencing both the undisturbed strength and the remoulded strength are reviewed with special reference to recent Canadian research. Included are discussions of cementing agents, specific surface, amorphous and smectite contents, and zeta potential controls as they influence depositional flocculation and postdepositional peptization.

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