ALBERT

Description / Table of Contents: The Holocene stratigraphy in Scoresby Sund is based on climatic change as reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly by emergence curves showing the patterns of isostatic uplift. From c. 10100-10400 to 9400 yr BP the major fjord glaciers showed oscillatory retreat with abundant moraine formation, the period of the Milne Land Moraines. The vegetation in the ice free areas was a sparse type of fell field vegetation but with thermophilous elements indicating temperatures similar to the present. From 9400 yr BP the fjord glaciers retreated rapidly in the narrow fjords, the few moraines formed are referred to the R0defjord stages and indicate topographically conditioned stillstands. At 8000 yr BP the low arctic Betula nana imigrated into the area, and in the period until 5000 yr BP dense dwarf shrub heath grew in areas where it is now absent. In the fjords the subarctic Mytilus edulis and Pecten islandica lived, suggesting a climate warmer than the present. From c. 5000 yr BP the dense dwarf shrub heath began to disappear in the coastal areas, and a 'poor' heath dominated by the high arctic Salix Arctica and Cassiope tetragona expanded. These two species, which are now extremely common, apparently did not grow in the area until c. 6000 yr BP. In lakes in the coastal area minerogenic sedimentation at c. 2800 yr BP, reflecting the general climatic deterioration.

Description / Table of Contents: Geochemistry is a science that is based on an understanding of chemical processes in the earth. One of the principal tools available to the chemist for understanding systems at equilibrium is thermodynamics. The awareness and application of thermodynamic techniques has increased at a very fast pace in geosciences; in fact, one may be so bold as to say that thermodynamics in geology has reached the "mature" stage, although much future thermodynamic research is certainly needed. However, the natural processes in the earth are often sluggish enough that a particular system may not reach equilibrium. This observation is being supported constantly by new experimental and field data available to the geochemist e.g. the non-applicability of the phase rule in some assemblages, the compositional inhomogeneities of mineral grains, the partial reaction rims surrounding original minerals, the lack of isotopic equilibration or the absence of minerals (e.g. dolomite), which should be present according to thermodynamics. The need to apply kinetics has produced a large number of papers dealing with kinetics in geochemistry. As an initial response to this growing field, a conference on geochemical transport and kinetics was conducted at Airlie House, VA, in 1973, sponsored by the Carnegie Institution of Washington. The papers there dealt with several kinetic topics including diffusion, exsolution, metasomatism and metamorphic layering. Since 1973 the number of kinetic papers has continued to increase greatly. Therefore, the time is ripe for a Short Course in Kinetics, which brings together the fundamentals needed to explain field observations using kinetic data. It is hoped that this book may serve, not only as a reference for researchers dealing with the rates of geochemical processes, but also as a text in courses on geochemical kinetics. One of us has found this need of a text in teaching a graduate course on geochemical kinetics at Harvard and at Penn State during the past several years. Finally, it is our hope that the book may itself further even more research into the rates of geochemical processes and into the quantification of geochemical observations. The book is organized with a rough temperature gradient in mind, i.e. low temperature kinetics at the beginning and igneous kinetics at the end (no prejudices are intended with this scheme!). However, the topics in each chapter are general enough that they can be applied often to any geochemical domain: sedimentary, metamorphic or igneous. The theory of kinetics operates at two complementary levels: the phenomenological and the atomistic. The former relies on macroscopic variables (e.g. temperature or concentrations) to describe the rates of reactions or the rates of transport; the latter relates the rates to the basic forces operating between the particular atomic or molecular species of any system. This book deals with both descriptions of the kinetics of geochemical processes. Chapter one sets the framework for the phenomenological theory of reaction rates. If any geochemical reaction is to be described quantitatively, the rate law must be experimentally obtained in a kinetically sound manner and the reaction mechanism must be understood. This applies to heterogeneous fluid-rock reactions such as those occurring during metamorphism, hydrothermal alteration or weathering as well as to homogeneous reactions. Chapter 2 extends the theory to the global kinetics of geochemical cycles. This enables the kinetic concepts of stability and feedback to be applied to the cycling of elements in the many reservoirs of the earth. Chapter 3 applies the phenomenological treatment of chapter 1 to diagenesis and weathering. The rate of dissolution of minerals as well as the chemical evolution of pore waters are discussed. The atomistic basis of rates of reaction, transition state theory, is introduced in Chapter 4. Transition state theory can be applied to relate the rate constants of geochemical reactions to the atomic processes taking place. This includes not only homogeneous reactions but also reactions that occur at the surface of minerals. Chapter 5 discusses the theory of irreversible thermodynamics and its application to petrology. The use of the second law of thermodynamics along with the expressions for the rate of entropy production in a system have been used successfully since 1935 to describe kinetic phenomena. The chapter applies the concepts to the growth of minerals during metamorphism as well as to the formation of differentiated layers (banding) in petrology. Chapter 6 describes the phenomenological theory of diffusion both in aqueous solutions and in minerals. In particular, the multicomponent nature of diffusion and its consequence in natural systems is elaborated. Chapter 7 provides the atomistic basis for the rates of reactions in minerals. Understanding of the rates of diffusion, conduction, order-disorder reactions or exsolution in minerals depends on proper description of the defects in the various mineral structures. Chapter 8 provides the kinetic theory of crystal nucleation and growth. While many of the concepts in the chapter can be applied to aqueous systems, the emphasis is on igneous processes occurring during crystallization of a melt. To fully understand both the mineral composition as well as the texture of igneous rocks, the processes whereby new crystals form and grow must be quantified by using kinetic theory. Due to space and time limitations (kinetics!) some topics have not been covered in detail. In particular, the mathematical solution of diffusion or conduction equations is discussed very well by Crank in his book, Mathematics of Diffusion, and so is not covered to a great extent here. The treatment of fluid flow (e.g. convection) is also not covered in the text.

Description / Table of Contents: Subsurface aspects of the ore-forming process can be described in terms of standard chemical transport parameters such as T-P gradients, mineral solubilities, solvent chemistry and volume, diffusion parameters and energy flow. These necessary factors are rather easily assessed by geochemical, isotopic and structural studies. If deposition is in the surface environment, a complex array of factors will determine the success of the natural concentration process and the chances of preservation of a deposit. Basically, most large-scale ore-forming processes involve large fluid volumes and energy sources. Many environments where these requirements are met, the modern ocean ridge and the subduction environment, are still not well understood. The need for remote-sensing techniques in the submarine environment is stressed.

Description / Table of Contents: Sediments beneath the Beaufort Sea near Prudhoe Bay, Alaska, were probed at 27 sites using a static cone penetrometer to determine engineering properties and distribution of material types, including ice-bonded sediments. The probe provided both point and casing resistance data and thermal profiles. At five sites these data were correlated with information from adjacent drilled and sampled holes. These control data and the quality of the probe information permitted profiles of sediment type and occurrence of ice-bonded material to be developed along three lines that included various geological features and depositional environments. Material properties were quite variable in the upper 14 m of sediments probed. In general, softer, finer-grained sediments occurred in the upper layers, while penetration refusal was met in stiff gravels to 10 to 12 m below the seabed. Seabed temperatures during the study were all below 0 C. However, because of uncertainties in freezing point values caused by brines, evaluation of the penetration resistance data was required to identify the occurrence of ice-bonded sediments. The coupling of thermal and penetration resistance data revealed that seasonally ice-bonded sediments occurred where the sea ice froze back to or near the seabed. Deeper, perennially frozen sediments also appeared to be present at several probe sites. The penetration data obtained can be used to aid in the design of shallow and deep foundations in both ice-bonded and unfrozen subsea sediments.

Description / Table of Contents: Uniaxial compression and tension tests were conducted on polycrystalline snow-ice to determine the effect of temperature on its strength. Test temperatures ranged from -O.1C to -54C. Two machine speeds, 0.847 mm/s and84.7 mm/s were used for the constant displacement rate tests. The compressive strength at -54C was about oneorder of magnitude higher than at -0.1C. The tensile strength at -18C was about 20% higher than at 0.1C. The initial tangent and 50% strength moduli are given for the compression tests, while the secant modulus to failure is given for the tension tests.The mode of fracture is discussed and the test results are compared with data from other investigations.

Description / Table of Contents: Ice fog suppression experiments on the Fort Wainwright Power Plant cooling pond were conducted during the winters of 1974-76. Baseline information studies occupied a sizable portion of the available ice fog weather in 1974-75. Then hexadecanol was added to the pond and dramatically improved visibility by reducing fog generated from water vapor released by the pond at -14 C. Although this temperature was not low enough to create ice fog, the cold vapor fog created was equally as devastating to visibility in the vicinity of the pond. During the winter of 1975-76, suppression tests were continued using films of hexadecanol, mixes of hexadecanol and octadecanol, and ethylene glycol monobutyl ether (EGME). Suppression effectiveness at colder temperatures was stuided and limits to the techniques were probed. A reinforcing grid was constructed that prevented breakup of the film by wind and water currents. Lifetime tests indicated that EGME degrades much more slowly than either hexadecanol or the hexadecanol-octadecanol mix. The films were found to be very effective fog reducers at warmer temperatures but still allowed 20% to 40% of normal evaporation to occur. The vapor thus produced was sufficient to create some ice fog at lower temperatures, but this ice fog occurred less frequently and was more quickly dispersed than the thick fog that was present before application of the films.

Description / Table of Contents: The objectives of this investigation were to describe channel characteristics and geographic settings of ice jam sites from aerial photographic interpretation, to indicate which characteristics may be important in causing ice jams, and to suggest additional uses of aerial photographs. Aerial photographs were taken of 19 sites with a Zeiss RMK 15/23 aerial camera on 17, 19, and 21 April 1976. Uncontrolled photomosaics of each site were assembled and major river characteristics were delineated on the photomosaics. Characteristics described include: manmade structures, falls, rapids, changes in channel depths, channel islands, mid-channel shoals or bars, river bed material, river sinuosity, meanders, floodplain width, riparian vegetation, and types of development on the floodplain. River channel widths were measured from the photographs along rivers where ground truth data were available for comparison. Lengths of channel riffles and pools were measured along the rivers where variations in river depths were evident on the photographs. Seventy-nine percent of the sites have some form of flow control structure which causes a pool with a backwater condition of low velocity. The low flow condition in the pool allows a solid ice cover to form which impedes ice movement and initiates ice jams. Aerial photographs provide a regional perspective for evaluating channel characteristics at an ice jam site and for analyzing the geographic setting at each site during ice-free conditions. Photographs taken after ice jams have formed are useful in monitoring ice jam formation, in analyzing ice characteristics, and in documenting ice jam breakup and movement.

Description / Table of Contents: Abstract: Ageneral computer model to simulate municipal snow removal has been developed. Programs which aid in the routing of snowplows are a part of this package. Once vehicle routes are created, the simulation program can be used to assess situations varying both equipment and meteorological parameters. Time for each plow to complete its route is calculated. Considerations are made for the above variable parameters plus plowing windrow, route starting depth, overlapping truck routes and intersection delay time. The effects of storm length, snowfall rate and starting depth on total plowing time are examined in a test case.

Description / Table of Contents: Tests were conducted to assess the extent of surface degradation resulting from the application of non-chloride deicing chemicals on three types of airfield pavements. The chemicals tested were proprietary mixtures of urea, formamide, and ethylene glycol; sodium chloride, distilled water, and dry specimens were used as controls and for comparison. Pavements included new and old specimens of open-graded asphaltic concrete and old specimens of dense-graded asphaltic concrete. Portland cement concrete specimens used were new and old, with and without air-entrainment. New and old tar rubber concrete specimens were also tested. Samples were subjected to up to 60 freeze-thaw cycles with deicing chemicals flooding their upper surface. Each specimen was rated on a scale of 0-5 after every five freeze-thaw cycles. All PCC specimens showed some surface degradation, whereas the dense- and open-graded asphaltic concretes were largely unaffected.

Description / Table of Contents: The spectral reflectance of natural snow in the range of 0.20- to about 0.40-micrometers wavelengths was studied in the laboratory using both continuous spectral scanning and fixed bandpass measurements. White barium sulfate pressed powder was used as a standard for comparison. The reflectance of fresh snow was found to be very high (usually nearly 100%) and only weakly wavelength dependent from 0.24 micrometers to the visible range. In the 0.20- to 0.24-micrometers portion of the spectrum, the reflectance was found to be quite erratic. Possible reasons for the irregularities in reflectance measurements are discussed.

Description / Table of Contents: A theory for ice forces acting on inclined wedges has been developed, thus making it possible to predict the magnitude of the intermittent ice forces from knowledge of the physical parameters of the system. The theory has been verified by model tests with artificial and natural ice.

Description / Table of Contents: This report discusses the relationship between an architect and a behavioral scientist. Some of the discussion applies to this cooperative work for design of buildings. The bulk, however, relates to the cooperation of architect and behavioral scientist while conducting research. Examples from collaborative research at Alaskan military installations are cited which demonstrate the roles and contributions of the two disciplines.

Description / Table of Contents: The theory of non-coaxial in-plane plastic deformation of soils that obey the Coulomb yield criterion is presented. The constitutive equations are derived by use of the geometry of the Mohr circle and the theory of characteristic lines. It is found that, for solving a boundary value problem, the non-coaxial angle must be given such values that enable us to accommodate the presupposed type of flow in the given domain satisfying the given boundary conditions. The non-coaxial angle is contained in the constitutive equations as a parameter. Therefore, the plastic material obeying the Coulomb yield criterion is a singular material whose constitutive equations are not constant with material but are variable with flow conditions.

Description / Table of Contents: Large, simply supported beams of temperate lake ice were found, generally, to yield significantly higher flexural strengths than the same beams tested in the cantilever mode. Data support the view that a significant stress concentration may exist at the fixed corners of the cantilever beams. Maximum effects are experienced with beams of cold, brittle ice substantially free of structural imperfections; for this kind of ice the strength difference factor, here attributed to the effect of stress concentrations, may exceed 2.0; that is, simply supported beams test a factor of 2 or more stronger than the same beams tested in the cantilever mode. In ice that has undergone extensive thermal degradation, the stress concentration effect may be eliminated entirely. Simply supported beams generally yield higher strengths when the top surfaces are placed in tension. This behavior is attributed to differences in ice type; the fine-grained, crack-free top layer of snow-ice which constituted up to 50% of the ice cover in the current series of tests usually reacted more strongly in tension than the coarse-grained crack-prone bottom lake ice.

Description / Table of Contents: The interaction of a 5.1-GHz transverse electric surface wave with a dielectric slab is experimentally investigated. The wave is initially supported by a dielectric substrate resting upon a metallic ground-plane. A slab, made of the same dielectric material as the substrate and variable in height, is then placed upon the waveguide. The results for a small slab sitting on the substrate showed that the discontinuity was a very inefficient launcher of reflected surface waves. Investigations of these reflections with a trough waveguide showed that, for values of slab height comparable to the exponential decay height of the surface wave, the reflections remain very small. However, as the slab height is increased beyond the decay height, the reflected amplitude approaches the theoretical value for a plane wave reflected from the interface between air and the same dielectric. The results are applicable to surface wave methods of microwave deicing of wings and helicopter rotors.

Description / Table of Contents: The viscoelastic deflection of an infinite floating ice plate subjected to a circular load was solved, assuming the Maxwell-Voigt type four-element model. An effective method of numerical integration of the solution integrals was developed, of which each integrand contains a product of Bessel functions extending to infinity. The theoretical curve was fitted to the field data, but the material constants thus found varied with time and location.

Description / Table of Contents: A new freezing mechanism, called segregation freezing, is proposed to explain the generation of the suction force that draws pore water up to the freezing surface of a growing ice lens. The segregation freezing temperature is derived by applying thermodynamics to a soil mechanics concept that distinguishes the effective pressure from the neutral pressure. The frost-heaving pressure is formulated in the solution of the differential equations of the simultaneous flow of heat and water, of which the segregation freezing temperature is one of the boundary conditions.

Description / Table of Contents: The mathematical theory for the bearing capacity of river ice for vehicles is presented. The floating ice sheet is assumed to have simple supports at the shore line. Solutions are presented for loads uniformly distributed over circular and rectangular areas. Numerical evaluations are made for a number of vehicles and the results presented in graphical form

Description / Table of Contents: The use of radio-echo sounding records to indicate the presence of internal layers within large ice sheets is of interest to glaciologists because it offers a means of tracking the internal properties of the ice sheets over large distances. The interpretation of the reflections obtained in this manner is more valuable, however, if a physical property change relating to the glaciological regime can be related to the dielectric property change producing the radio-echo reflections. In this report, we use the measured physical properties of core to bedrock taken at Cape Folger, East Antarctica (66 deg 22 min s, 111 deg (E), 324-m depth), to compute a profile of dielectric properties and from this, a depth-reflection coefficient profile for comparison with observed radio-echo reflections. The measurements available on physical properties are: density variations, bubble size and shape changes, and crystal fabric variations. The depths of the strong reflections shown on the available radio-echo records are in reasonable agreement with the depths corresponding to the highest reflection coefficients computed from the combined physical property measurements. In calculations to differentiate the separate effects of different physical properties, it appears that density variations account for the primary contributions to the calculated dielectric property changes corresponding to the highest reflection coefficients. However, bubble changes alone can also account for reasonable, though lower, reflection coefficients at the appropriate depths. Crystal fabric variations correspond poorly with the reflection locations. Density variations are normally associated with depositional events in the history of the ice sheet.

Description / Table of Contents: Many of the technical questions relating to iceberg transport are given brief, but quantitative, consideration. These include iceberg genesis and properties, the mechanical stability of icebergs at sea, towing forces and tug characteristics, drag coefficients, ablation rates, and handling and processing the iceberg at both the pick-up site and at the final destination. In particular the paper attempts to make technical information on glaciological and ice engineering aspects of the problem more readily available to the interested planner or engineer. Specific conclusions include: (1) No unprotected iceberg, no matter how long or wide, would be likely to survive the ablation caused by a long trip to low latitudes. (2) Icebergs that have a horizontal dimension exceeding 2 km may well be prone to breakup by long wavelength swells. (3) To avoid the dangers associated with an iceberg capsizing, the width of a 200-m thick iceberg should always be more than 300 m. (4) For towing efficiency the length/width ratio of a towed iceberg should be appreciably greater than unity. (5) For a pilot project, the selected iceberg would have to be quite small, if for no other reason than the practical availability of tug power.

Description / Table of Contents: This report summarizes the advances in understanding of the Arctic which have come about since the inception of the ARPA Arctic Surface Effect Vehicle Program in 1970, primarily as the result of CRREL’s participation. Major efforts to increase knowledge of sea ice, terrestrial, and coastal topographic features are described. Special empha­sis is placed upon the quantitative understanding of pressure ridging. Other areas of major interest are atmospheric characteristics and ecological effects. A list of publications generated is included.

Description / Table of Contents: Mining Research Corporation, Inc., under contract with Snow Ice, and Permafrost Research Establishment, Corps of Engineers, U.S. Army, conducted explosion tests in frozen Keweenaw silt, to determine; (1) the most efficient type of explosive for blasts in frozen ground, (2) the fundamental relation between weight of explosive and depth of charge, (3) the proper position of the charge relative to the frozen-ground interface, (4) the feasibility of fracturing the frozen layer by placing a charge in the underlying unfrozen material, and (5) the effect of the diameter of the borehole and of the shape of the charge upon the resultsof blasting. Information obtained from the tests applies to the specific problem of excavating in frozen ground and to fundamental explosives research. Conclusions and recommendations based on this information are presented here concerning the feasibility of using explosives for fox-holes in frozen ground; methods of placing the charge; mechanics of crater formation; the crater equation; future instrumentation; classification of explosives; and correlation of blast data.

Description / Table of Contents: The thermal structure and ice conditions of Lake Champlain, a mid-latitude large lake, near Shelburne Point, Vermont, were studied during the winter of 1974-75. The lake was instrumented to a depth of 8.5 m with a string of highly calibrated thermistors, connected to a data logger on shore which recorded water temperatures every four hours. An ice mooring system was developed to anchor the thermistor string so that ice and water temperatures could be obtained at known levels. This temperature recording system measured vertical and horizontal variations in ice and water temperature regimes during ice formation, growth and decay. Meteorological data were measured during the winter period November 1974 through March 1975 at the site. Ice stratigraphy was determined for the ice at the site at its maximum seasonal growth for comparison with ice from St. Albans Bay (at the northern end of Lake Champlain) which had formed earlier. Correlations were determined between ice growth and accumulated degree days of freezing. The operation of a bubbler system installed near the measurement site around a service dock was observed.

Description / Table of Contents: CONTENTS: Abstract. - Preface. - Introduction. - Test locations. - Post Pond. - Mascoma Lake. - Winter freeze-up. - Ice cover properties. - Stratigraphy. - Microstructure. - Porosity. - Impurity content. - Flexural strength. - Test sites. - Beam test procedure. - Beam dimensions. - Beam temperatures. - Beam strengths. - Results. - Post Pond, Site PB, 12 February 1974. - Post Pond, Site PC, 21 February 1974. - Mascoma Lake, Site MD, 25 February 1974. - Mascoma Lake, Site MD, 26 February 1974. - Mascoma Lake, Site MD, 1 March 1974. - Post Pond, Site PA, 4 March 1974. - Post Pond, Site PA, 7 March 1974. - Post Pond, Site PA, 8 March 1974. - Post Pond, Site PB, 12 March 1974. - Post Pond, Midway between Sites PB and PC, 15 March 1974. - Post Pond, Midway between Sites PA and PB, 26 March 1974. - Post Pond, Midway between Sites PA and PB, 29 March 1974. - Post Pond, Midway between Sites PA and PB, 3 April 1974. - Conclusions. - Literature cited.

Description / Table of Contents: In-place cantilever beam tests on Post Pond and Mascoma Lake ice yielded a maximum flexural strength of 7.1 kg/cm^2. The minimum strength, unrelated to failure along pre-existing cracks in the ice, was 2.9 kg/cm^2. The majority of tests were performed in the push-down mode after it was discovered that beams tested in the pull-up mode, which places the bottom surface in tension, frequently broke prematurely along cracks in the bottom of the ice. Premature failures of this kind usually occurred at stresses of 2-3 kg/cm^2. Data further demonstrate that the intrinsic strength of lake ice decreases significantly as the surface air temperature goes to 0°C. Ice that has just become isothermal, but has not yet begun to candle, has a strength of about 4 kg/cm^2; ice that has been subjected to prolonged periods of above-freezing air temperatures generally fails at about 3 kg/cm^2. Tests also show that cold unrecrystallized snow-ice is as strong as the underlying lake ice. Tests of the effect of crystalline structure indicate that ice composed of crystals with their c-axes horizontal is measurably stronger than ice in which the crystals are oriented with their c-axes vertical.

Description / Table of Contents: CONTENTS: Abstract. - Preface. - Introduction. - Experimental procedure. - Results. - Work-hardening effect. - Strain rate sensitivity of flow stress. - Discussion. - Conclusions. - Literature cited.

Description / Table of Contents: Single crystals of high purity ice deformed by uniaxial compression on an Instron machine showed remarkable work-hardening after about 8% strain. By changing the strain rate during compression tests in the plastic region of the stress-strain curve, an apparent activation volume V* and a dislocation mobility exponent m were calculated from the strain rate sensitivity of flow stress. The large work-hardening and the rapid increase in the value of m beyond about 10% strain indicate that the plastic flow in this region is controlled by dislocation intersections and nonconservative motion of jogs.