ALBERT

Description / Table of Contents: CONTENTS: Introduction. - Sea ice as a material. - Experimental procedures. - Results and analysis. - Conclusion. - Literature cited. - Appendix A. Error analysis. - Abstract.

Description / Table of Contents: An investigation is made into the determination of the relationship between the extinction coefficient and the salinity of sea ice. A HeNe laser is used to propagate a beam of red light, of wavelength 6328Å, through a series of ice samples at -20°C. The optical extinction coefficients were calculated and plotted against the measured salinities. The results of the experiment indicated an exponential relationship between extinction coefficient and salinity. The relationship may be described by the equation: y = 2.41 + 0.001 exp (1.19x) where y is the extinction coefficient and x is the salinity.

Description / Table of Contents: CONTENTS: Introduction. - 1. Coastal stations. - Alaska. - Canada. - Greenland. - Europe and Russia. - II. The interior Arctic Ocean. - Zone 1. - Zone 2.. - Zone 3. - Zone 4. - Zone 5. - Zone 6.. - Summary and discussion. - Supplemental data. - Literature cited. - Appendix A. Winds. - Appendix B. Arctic surface winds. - Appendix C. Excerpt from Cold Regions Science and Engineering, USA CRREL Monograph I-A3b. - Appendix D. Excerpt from Proceedings of the Arctic Basin Symposium October 1962. - Abstract.

Description / Table of Contents: Prevailing monthly and seasonal surface wind directions were obtained from 1) weather records for 21 coastal stations around the Arctic Ocean and 2) a series of U.S. Navy wind charts for 15 to 20 locations in the arctic marginal seas and the ocean's interior. This information was combined and analyzed to develop 2 charts which depict the surface flow of air in these areas during the mid-summer and mid-winter months. Since the ice floe stations used in the offshore wind analysis are not permanently located, the Arctic Ocean was selectively divided into 6 zones. Three of these zones separate Polar regions north of 84°N latitude, and 3 other zones each separate the seas bordering the north coasts of Europe, Siberian Russia and North America. Except for a few stations where wind directions are apparently controlled by local influences the results showed the following mid-winter patterns: 1) a near anticlockwise flow within the circle north of 75°N, 2) winds from the north in and near the Chukchi and Bering Seas, 3) northeast winds along the Alaskan coast and northwest along the Canadian Archipelago Islands, and 4) southwest and southeast winds along the northern coasts of Europe and Asia respectively. Although the wind directions during mid-summer become more variable the study showed that the prevailing surface winds for most areas in this season are nearly opposite those observed in winter.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Glenn Creek watershed. - Location. - Topography. - Geology, soils and permafrost. - Climate. - Vegetation. - Data collection. - Precipitation. - Stream flow. - Air temperature and relative humidity. - Water temperature. - Evaporation. - Snow surveys. - Depth of thaw. - Dissolved solids. - Hydrology. - Introduction. - General channel description. - Hydraulic geometry. - Characteristics of hydrographs. - Sources of streamflow. - Attempts at flow separation. - Hydrograph modeling. - Summary and conclusions. - Literature cited. - Appendix A: Summary of permafrost probe observations, Glenn Creek watershed.. - Appendix B: Water-holding and-transmitting properties of moss. - Appendix C: Summary of hydraulic geometry data from 1964 discharge measurements. - Appendix D: Summary of data used in computing recession constants.

Description / Table of Contents: The results of a four-summer (1964-1967) hydrologic study of the watershed of Glenn Creek, about 8 miles north of Fairbanks, Alaska, in the Yukon-Tanana uplands physiographic province, are presented. This work was initiated to provide initial baseline hydrologic data for a small subar ctic watershed, the first of its kind in North America. Standard hydrologic and meteorologic instrumentation was used, and streamflow characteristics were analyzed by standard hydrograph-analysis techniques. The stream is second-order, and drains an area of 0.70 square mile. Basin elevations are from 842 ft to 1618 ft. In regard to topography, geology, soils, permafrost, vegetation, and climate, the watershed seems to be representative of low-order, low-elevation drainage basins in the province. Analysis of rainfall-runoff data indicates that about half the 12.3-in. normal annual precipitation is runoff. The remainder is the actual evapotranspiration , which equals only about 30% of estimated potential evapotranspiration. For individual storms, runoff/rainfall proportions were from 0.03 to 0.42 and were positively correlated with antecedent discharge of the stream, which is a measure of watershed wetness. The stream responds rapidly to rainstorms except when the basin is very dry, and has markedly slow recessions compared with temperate region streams of similar size. Rate of recessions is apparentlv controlled by concurrent evapotranspiration rates. Analysis of hydrographs and knowledge of the physical characteristics of the basin indicate that storm runoff occurs initially as surface runoff from bare soil areas adjacent to the stream, while recessions are dominated by a combination of tunnel flow beneath moss-covered parts of the basins and typical groundwater flow through the moss and soils. Peak discharges for individual storms could be well estimated by an equation including antecedent discharge, total precipitation and storm duration, and average recession constant. These results represent the first detailed hydrologic data from the discontinuous permafrost zone of the North American taiga and should be of significance to the International Hydrological Decade and International Biological Program.

Description / Table of Contents: CONTENTS: Preface. - Introduction. - Principle of the IR scanner. - Advantages of mobile infrared thermography. - Discussion of field measurements. - Recommendations for future work on thermography of buildings. - Other potential applications of infrared thermography of buildings. - Appendix A: Thermograms of northern exposure of USA CRREL building. - Appendix B: Sample thermograms of heat loss survey at Pease Air Force Base. -Appendix C: Sample thermograms of heat loss survey at Dartmouth College. - Abstract.

Description / Table of Contents: A method to assess quickly the insulation effectiveness of buildings using mobile infrared thermography has been developed at USA CRREL. In contrast to the infrared thermography done in Sweden, this method concentrates on obtaining useful data by measuring the outside surface temperature of structures. This report outlines the basic principles involved in these measurements, and discusses field measurements and the inherent advantages of infrared thermography. Typical thermograms are presented in the appendixes.

Description / Table of Contents: CONTENTS: Introduction. - Drilling and field observations. - Interpretation. - Implications for the feasibility study. - Conclusions. - Literature cited. - Abstract.

Description / Table of Contents: Two holes were drilled through the Greenland ice sheet during 1973 and temperature measurements were made in one hole drilled during 1972. These measurements show that the area of liquid water beneath the ice cap extends to ice depths as shallow as 100 m. The consequences of removing the frozen margin of glacial ice could be serious and more temperature measurements are needed to exactly locate the subglacial water. Petrographic studies of a few ice cores revealed a strongly oriented crystal fabric and an appreciable surface accumulation of superimposed ice.

Description / Table of Contents: Experiments by Smith-Johannsen on the adhesion of ice frozen from a number of 1 x 10^-3 ? electrolyte solutions to a wax-treated aluminum surface at -10°C are discussed. It is concluded that the adhesive strength measured by the force per square centimeter needed to shear the ice off the substrate surface is mainly due to a liquid interfacial solution layer between the ice and the substrate surface. The thickness of such a layer is largely determined by the same considerations as the thickness of grain boundary layers in ice obtained from dilute electrolyte solutions.

Description / Table of Contents: CONTENTS: Introduction. - Materials and methods. - Materials. - Methods. - Results and discussion. - Literature cited. - Appendix A.

Description / Table of Contents: Clay mineral and soil samples were subjected to neutron activation analysis in order to identify and measure the abundances of trace elements having radionuclides with long half-lives. After exposure of cadmium-shielded samples to neutrons for a period of five days, the gamma radiation associated with the decay of the resulting radionuclides was observed using a high resolution Ge(Li) detector. Trace elements identified without prior chemical separation using the gross gamma-ray spectra included Fe, Zn, Ti, Ni, Co, Cr, Sr, Ba, Ca, La, Eu, Tb, Hf, Ta, Th, and U. It should be possible to determine quantitatively the amount of each of these elements. This is a considerable improvement over the number of elements determined in soils previously by activation analysis without destructive chemical treatments.

Description / Table of Contents: Contents: Preface. - List of symbols. - Introduction. - Adsorption of volatile chemicals by soil. - Introduction. - Experimental procedure. - Results and discussion. - Diffusion of volatile chemicals in soil. - Introduction. - Experimental procedure. - Calculations. - Results and discussion. - Prediction of vapor diffusion in soil. - Introduction. - Construction of model. - Computations. - Results and discussion. - A statistical method for analysis of diffusion through soil. - Introduction. - Theory. - Application. - Literature cited. - Abstract.

Description / Table of Contents: Detection of mines, explosives, and tunnels may be accomplished by sensing associated volatile effluvia. This investigation was undertaken to provide a basis for predicting the diffusion of volatile compounds from underground sources into the atmosphere. Diffusion of a volatile compound was studied for a range of soil conditions utilizing soils from the mine detection sites in Puerto Rico. A new mathematical analysis based on the Monte Carlo method was developed for predicting vapor diffusion through soil into the atmosphere. It was determined that diffusion in soil can be reliably predicted if soil porosity, moisture content, and affinity for the compound are known. Appearance in the atmosphere is also dependent on accumulation of the compound in air at the soil/atmosphere interface. Diffusion of volatile compounds through soil into the atmosphere is not likely to be an important factor in tunnel detection due to depth of overburden. However, adsorption of compounds at tunnel walls is likely to significantly reduce the amount of vapor appearing in the atmosphere through entrances and vents. Detection in the atmosphere of TNT vapor from mines and explosives buried in moist, porous soil should be possible under ideal sample collection conditions.

Description / Table of Contents: The solution for the vibration of an elastic plate floating on water is developed. The water is assumed to be incompressible and to have irrotational flow. In free vibration upon release of the plate, the maximum negative rebound of the deflection is 25%. For forced vibration, the steady state part of the solution shows that there is a frequency at which the deflection is a maximum. The stresses become a maximum at a frequency higher than the one for deflection. These critical frequencies depend upon the plate's characteristic length and the depth of the water. For most situations the critical frequency for stress is less than 0.2 cycle per second. At this critical frequency the stresses are amplified over the static case by a factor less than 10%.

Description / Table of Contents: CONTENTS: Preface. - Nomenclature. - Introduction. - Funicular regime. - Grain growth. - Grain contacts. - Densification. - Pendular regime. - Discussion and conclusions. - Literature cited. - Abstract.

Description / Table of Contents: Grain growth, bond growth and densification of wet snow are described in terms of the distribution of equilibrium temperature in the snow matrix. At high water saturations the equilibrium temperature increases with grain size; hence, small particles melt away as large particles grow. Melting also occurs at the intergrain bonds, causing a low strength and rapid densification. At low saturations the equilibrium temperature is determined by the capillary pressure and the particle sizes have only a second order effect. Therefore, grain growth proceeds slowly and, even at large overburden pressures, no intergrain melting occurs. At low saturations the water "tension" acts through a finite area, thus large attractive forces exist between the grains, and the strength of the snow matrix is large.

Description / Table of Contents: CONTENTS: Introduction. - Previous work. - Sea ice terrain model. - Traffic ability model. - Analytic calculation of DT/DSL. - Monte Carlo calculation. - Results of traffic ability computations. - Experimental traffic ability ratios using ridge overlays. - Regional variations in ridging intensity. - Additional traffic ability aspects of sea ice. - Shear zone and rubble fields. - Linear lead systems. - Conclusions. - Literature cited. - Appendix A. Distribution of the lateral extent of ridges. - Abstract.

Description / Table of Contents: A sea ice terrain model, based upon previously tested height and spacing distributions for sea ice pressure ridging, is developed. Using this model, and additional information on pressure ridge extents, a trafficability model for vehicles traversing the pack ice is developed. Both analytic and Monte Carlo calculations of vehicle trafficability, measured in terms of the average ratio of the total distance traveled over a straight-line distance, are performed. The calculations include cul-de-sacs due to ridge intersections. The trafficability ratio is given as a function of ridge-height-clearance ability of the vehicle and of ridging parameters which may be obtained from laser profiles of the arctic pack ice. Results are in good agreement with simulated routes through sea ice terrain taken from aerial photo mosaics. Contour plots of ridging parameters taken from laser profilometry are also supplied. These plots, together with the trafficability model, supply mobility information for the whole of the western portion of the Arctic Basin.

Description / Table of Contents: CONTENTS: Preface. - Notation. - Introduction. - Review of observations. - Review of theory. - Water flow through textured layers. - Water flow past semipermeable layers. - Discussion. - Literature cited. - Abstract.

Description / Table of Contents: The flow of water through layered snowpacks is discussed. A method for predicting flow through unsaturated layers is given. The flow along ice layers and through ice layers is analyzed in terms of the slope, permeability, thickness and length of the layers. It is shown that the permeability of ice layers required to cause large flow diversions is quite small. The effect of slope is large even at small angles.

Description / Table of Contents: CONTENTS: Preface. - Symbols. - Introduction. - Physical setting. - Flow model. - Calculated flow. - Existing profile. - Proposed profiles. - Profile 1. - Profile 2. - Profile 3. - Profile 4. - Profile 5. - Profile 6. - Profile 7. - Total excavation. - Interpretation and conclusions. - Sources of error. - Recommendations. - Literature cited. - Appendix A. - Abstract.

Description / Table of Contents: The Marcona Corporation and Kryolitselskabet ?resund, A/S (a Danish corporation) are cooperatively investigating the possibility of developing an open-pit mine along the edge of the Greenland Ice Cap. The response of the glacier to a sudden change in surface slope and thickness is calculated. The existing flow is diverted away from the mineral deposit but will increase when the excavation begins. It is calculated that 66 million cubic meters of ice must be removed in order to establish a stable profile beyond the pit. An additional 7.9 million cubic meters of ice must be removed yearly in order to maintain the profile.

Description / Table of Contents: CONTENTS: Preface. - Introduction. - Theory of formation, growth and precipitation of ice crystals. - Fog characteristics. - Liquid water content. - Size distribution of liquid water droplets. - Results and discussion. - Sudden expansion system. - Continuous flow. - Conclusions and recommendations. - Conclusions. - Recommendations. - Literature cited. - Abstract.

Description / Table of Contents: Two compressed air systems for glaciating supercooled clouds were studied in the laboratory. The first system used the sudden expansion of compressed air and was found to be most efficient at 27 psig producing an average of 5.2 x 10^8 ice crystals per cm^3 of air. The second system used a continuous flow of air through nozzles of various designs, of which the supersonic nozzle was found to be the most efficient, producing a maximum of 2.5 x 10^8 crystals per cm^3 of air at 27 psig. The above data were obtained at an ambient temperature of -4°C, but data for other temperatures and pressures were obtained and are presented in the text.

Description / Table of Contents: CONTENTS: Introduction. - Regional setting. - General description and topography. - Geology. - Soils. - Climate. - Precipitation. - Temperature. - Weather during period of study. - Vegetation. - Hydrology. - Water balance. - Introduction. - Yield. - Precipitation. - Loss of glacial storage. - Evapotranspiration. - Summary. - Flow variability. - Flow-duration curves. - Flood estimation. - Response to rain and meltwater. - Water quality. - Introduction. - Suspended sediment. - Bedload. - Dissolved sediment. - Water temperatures. - Channel shape and process. - General characteristics of braided channels. - Channel material. - Channel shape. - Channel changes. - Introduction. - Channel profiles. - Ground photography. -Vertical aerial photography. - Freeze-up and breakup. - Summary. - Literature cited. - Selected bibliography. - Appendix A: Measurement site locations and methods. - Appendix B: Installation of water-level recorder. - Appendix C: Delta river quicksilts - properties and mode of formation. - Appendix D: Channel shape data. - Abstract.

Description / Table of Contents: A one-year reconnaissance study was made of a large braided glacial river and its drainage basin (drainage area 1665 m^2; elevation range 1000 - 10,000 ft) for which a minimum of hydrometric and meteorologic data existed. The report includes estimates of the water balance, flow-duration curves, and sediment characteristics, and descriptions of stream response to glacial melt and rain, channel geometry and channel processes. Mean annual basin precipitation is estimated at 40.4 in. and mean annual loss of permanent glacial storage is about 1 in. About 30% of this leaves the basin as evapotranspiration, 50% as stream flow, and 20% as groundwater flow. Characteristics of response to glacial melt are outlined. Flow peaks near the mouth occur within 24 hours of rainfall Greater than 0.5 in./day at foothills meteorological stations; rains of less than that amount do not generally produce discernible stream response. Stream channel geometry is described in detail. Most channels on the lower floodplain are asymmetrical and are roughly triangular or parabolic, and have high width/depth ratios. At-a-station hydraulic geometry is described. Surveys and gr ound and aerial photography are used to describe channel changes.

Description / Table of Contents: CONTENTS: Introduction. - Literature review. - Experimental procedure. - Experimental and theoretical equations. - Results and discussion. - Conclusions. - Literature cited. - Appendix A. Some problems in the experimental determination of the extinction coefficient of ice fog. - Appendix B. Ice fog production technique. - Appendix C. Ice fog samples and their corresponding particle spectra. - Abstract.

Description / Table of Contents: Laser extinction measurements in ice fog were made at wavelengths of 0.6328, 1.15 and 3.39 microns. The ice fog was generated in an environmental chamber whose temperature could be lowered to -43°C. Particle sampling was carried out simultaneously with the laser measurements using an impactor. Size distributions were derived from the impactor measurements. These data were used to compute Mie extinction coefficients at the three laser wavelengths. These coefficients were compared with the coefficients derived experimentally. Although some discrepancy exists between theory and experiment, both agree fairly well on the behavior of the extinction coefficient as a function of particle concentration.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - I. Introduction. - II. A statistical theory of trafficability. - Statistical descriptions of trafficability. - Statistical modeling of trafficability. - Trafficability in a variable space with comparison to a fixed space. - III. Statistical description of sea ice. - Homogeneous, isotropic, and normal random function. - Upper bound of probability for finding an obstacle derived from two-point probability density function. - IV. Design criteria of a SEV derived from sea ice surface roughness. - Literature cited. - Appendix: Statistics of a variable space.

Description / Table of Contents: Efforts were made to derive the design criteria of surface effect vehicles operated on arctic sea ice. Statistical theories were developed to describe trafficability of the vehicles and topography of the sea ice. By the use of actual sea ice surface profiles obtained by an aerial laser profiler, the usefulness of the present statistical method was demonstrated.

Description / Table of Contents: CONTENTS: Introduction. - Determination of CEC of earth materials using isotopic exchange. - Determination of CEC of earth materials using isotopic labeling. - Appendix: Procedure for determination of CEC of earth materials by isotopic labeling.

Description / Table of Contents: Two radiochemical methods were investigated for determining the cation exchange capacity of earth materials having a wide range in physicochemical properties. The first method attempted was unsuccessful but involved determination of the radioactivity of a 22Na-NaOAc solution in isotopic equilibrium with a Na+-saturated mineral phase. The logic of this method is presented in order to illustrate principles of isotopic exchange in mineral systems. The method finally adopted is based upon determination of the radioactivity of a salt-free, Na+-saturated mineral sample prepared using a radioactive NaOAc solution with a known 22Na-NaOAc composition. This method is less time-consuming and more accurate than the conventional ammonium acetate method for cation exchange capacity determinations.

Description / Table of Contents: CONTENTS: Introduction. - Analytical procedures. - Measurement of crystal size. - Measurement of crystalorientation. - Results and discussion. - Byrd Station crystal structure and fabrics. - Little America V crystal structure and fabrics. - Conclusions. - Literature cited. - Abstract.

Description / Table of Contents: Radical differences in the crystal structure and fabrics of glacier ice cores at Byrd Station and Little America V, Antarctica, are attributed to gross differences in the thermal and deformational histories of the ice at these two locations. At Byrd Station the mean size of crystals increased more than sixfold between 65 m and the bottom of the drill hole at 309 m. Crystal size was also found to increase linearly with the age of the ice, thus simulating isothermal grain growth in metals. However, this growth was not accompanied by any dimensional orientation of crystals or entrapped bubbles, or by any significant increase in the degree of preferred orientation of crystallographic c-axes. These observations imply that negligible shearing is occurring in the top 300 m of the thick grounded ice sheet at Byrd Station. By contrast very considerable deformation is indicated for the floating 258-m-thick Ross Ice Shelf at Little America. This deformation is characterized by the widespread occurrence of "strained" crystals below 65 m, the existence of elongated oriented bubbles between 95 m and 130 m and the attainment of pronounced crystal orientation (multiple-maxima fabrics) by 100-m depth. Exaggerated growth of crystals below 150 m is attributed to increasing temperatures in the ice shelf. The crystal structure of these cores clearly demonstrates that glacial ice only is present in the Ross Ice Shelf at Little America V.

Description / Table of Contents: CONTENTS: Introduction. - Field sites and procedures. - Results. - Discussion. - Conclusions. - Literature cited. - Appendix A: Tabulation of AIDJEX core data. - Appendix B: Tabulation of average salinity/ice thickness data. - Abstract.

Description / Table of Contents: The salinity distribution in multiyear sea ice is dependent on the ice topography and cannot be adequately represented by a single average profile. The cores collected from areas beneath surface hummocks generally showed a systematic increase in salinity with depth from 0 0/00 at tne surface to about 4 0/00 at the base. The cores collected from areas beneath surface depressions were much more saline and displayed large salinity fluctuations. Salinity observations from sea ice of varying thicknesses and ages collected at various arctic and subarctic locations revealed a strong correlation between the average salinity of the ice, S, and the ice thickness, h. For salinity samples collected from cold sea ice at the end of the growth season, this relationship can be represented by two linear equations: S = 14.24 - 19.39h (h? 0.4 m) ; S = 7.88 - 1.59h (h 〉 0.4 m) . It is suggested that the pronounced break in slope at 0.4 m is due to a change in the dominant brine drainage mechanism from brine expulsion to gravity drainage. A linear regression for the data collected during the melt season gives S = 1.58 + 0.18h. An annual cyclic variation of the mean salinity probably exists for multiyear sea ice. The mean salinity should reach a maximum at the end of the growth season and a minimum at the end of the melt season.

Description / Table of Contents: CONTENTS: Introduction. - Part 1.The concept of isotropy clarified by the introduction of non-coaxial mechanics. - Part 2. Systematization of the theory of plasticity with indefinite angle of non-coaxiality. - Analysis of stress. - Analysis of strain-rate. - Principle of partial coincidence. - Strain-rate characteristic directions. - Equations for practical use. - Conclusion. - Literature cited. - Appendix A.The sense of the [Sigma],[Gamma] coordinate system. - Appendix B. Another derivation of the equations of velocity components. - Appendix C. Equations of velocity components in stress characteristic directions.

Description / Table of Contents: One of the difficulties that have hampered the development of the mathematical theory of soil plasticity was recently overcome by Mandl and Luque. They showed that the non-coaxiality of the principal axes of a stress tensor and a strain-rate tensor can occur only in plane deformation. Their assumption that the angle of non-coaxiality should be a material constant cannot be supported, however. The angle of noncoaxiality should be determined so that the solution to the given problem can exist. It is demonstrated in one of the examples in this paper that a well-known solution in which the angle of non-coaxiality is assumed to be zero does violate the assumed boundary condition. The theory was reorganized bv using new insights given by Mandl and Luque. It is concluded that still missing is one condition that enables us to determine the angle of non-coaxiality as a function of space.

Description / Table of Contents: CONTENTS: Preface. - Introduction. - Part 1:Mesoscale strain measurements on the Beaufort Sea pack ice. - Abstract. - Introduction. - Previous work. - Site location. - Results. - Correlation of synoptic aerial photography with measured strains. - Correlation of estimated wind stress and strain. - Conclusions. - Literature cited. - Part II: Structure of a multiyear pressure ridge. - Abstract. - Introduction. - Profiles. - Internal properties. - Largest ridge sail. - Conclusions. - Literature cited. - Part III: Top and bottom roughness of a multiyear ice floe. - Abstract. - Introduction. - Results. - Literature cited. - Part IV:Airphoto analysis of ice deformation in the Beaufort Sea Abstract. - Introduction. - Study area. - Method of analysis. - Ice deformations. - Net deformational changes. - Pressure ridge distribution. - Summary and conclusions. - Literature cited. - Part V: Data on morphological and physical characteristics of sea ice in the Beaufort Sea.

Description / Table of Contents: Mesoscale strain measurements on the Beaufort Sea pack ice; Structure of a multiyear pressure ridge; Top and bottom roughness of a multiyear ice floe; Airphoto analysis of ice deformation in the Beaufort Sea; Data on morphological and physical characteristics of sea ice in the Beaufort Sea.

Description / Table of Contents: CONTENTS: Preface. - Nomenclature. - Introduction. - Test specimen. - Equipment and procedure. - Test chamber. - Error of eccentricity. - Equipment. - Procedure. - Results. - Tensile strength. - Fracture. - Discussion. - Uniaxial tensile strength. - Brazil test. - Comparison with theory. - Conclusions. - Literature cited. - Appendix A. Test results. - Abstract.

Description / Table of Contents: An investigation was conducted to determine the effect of a compressive stress on the tensile strength of bubbly polycrystalline ice. One hundred forty-five tests were made in an apparatus of novel design. A cylindrical dumbbell specimen was stressed in axial tension and radial and tangential compression by a hydraulic system which minimized bending stresses. Compression-tension ratios ranging from 0.21 to 10.14 were used for the tests. Tensile strength was found to decrease with an increase in the ratio. At the ratio of 3.155 the tensile strength is about one third the uniaxial value. The test results support the evidence that the Brazil test underestimates the tensile strength for ice. They also indicate that the Brazil test value for ice can be no greater than one third the uniaxial tensile strength. A comparison of the experimental results with a few prominent biaxial failure theories indicates a lower tensile strength than predicted by any theory. However, the best approximation to the results is the Coulomb-Mohr criterion.

Description / Table of Contents: CONTENTS: Introduction. - Study lake. - Previous work at Post Pond. - Methods and procedures. - Results and discussion. - Summer stratification. - Autumnal mixing and thermocline disappearance. - Winter period of ice cover. - Spring circulation. - Summary and conclusions. - Literature cited. - Appendix A: Ice sample analysis. - Abstract.

Description / Table of Contents: The temperature structure of Post Pond, a small (46.6 hectares), mid-latitude, dimictic lake in west-central New Hampshire, was studied during autumn,winter and spring of 1968-1969. The lake was instrumented over its maximum depth (11.7 m) with a string of 24 thermocouples which recorded hourly temperatures. Temperatures in 9 m of sediments underlying the lake were measured with a thermistor probe. Secondary and tertiary thermocline development in the epilimnion occurred during short warming periods in the early autumn. The autumn overturn lasted 25 days, whereas the spring overturn lasted only 4 days. The entire lake mixed isothermally in the autumn to 3.2°C. During the period of ice cover, the lower 5 m of water gained approximately 51.5 cal/cm^2, which was supplied by stored heat in the bottom sediments. A steady-state thermal gradient of 0.07°C/m was found for the deeper sediments underlying the lake during ice cover. Late winter cooling of bottom water under the ice cover may be the result of snowmelt in areas adjacent to the lake causing activation of groundwater influx. Melting of the clear ice portion of the ice cover was primarily the result of heat supplied to the lake from snowmelt water, and occurred on the underside of the ice sheet. Thermal instability of the water mass persisted for 9 days during peak snowmelt runoff; this can be partially explained by an increase in dissolved solids with depth.

Description / Table of Contents: Hugoniot curves were generated from simultaneous measurements of shock and free-surface velocities, obtained from samples of frozen Fairbanks (Fox) silt, using the exploding wire technique. The abrupt change in slope of the Us-Up Hugoniot is indicative of a phase change. The shape of the P-V Hugoniot suggests that the transformation begins immediately but does not go to completion. This means that, although the pressure lies slightly above the Rayleigh line through the mixed phase region, the slope does not increase as rapidly as it would if the material had stayed in the initial phase.

Description / Table of Contents: CONTENTS: Preface. - Conversion factors. - Introduction. - Test procedure. - Test results. - Discussion. - Literature cited. - Appendix A: Hugoniot data. - Abstract.

Description / Table of Contents: CONTENTS: Introduction. - Physical basis of microwave moisture sensing. - Physics of transmission and reflection. - General behavior of reflection and transmission of electromagnetic waves through media of finite thicknesses. - Water-content determination by reflection or transmission measurements on micro-waves. - Outlook for microwave moisture sensors. - Future studies. - Bibliography. - Appendix A. Computer program. - Abstract.

Description / Table of Contents: Microwave instrumentation is used for nondestructive measurement of the water content of materials. The basis of all microwave moisture sensors is that the dielectric constants of material that contains water are a strong function of water content. The microwave moisture sensors based on a reflection or transmission principle are shown to have the disadvantage of requiring that a calibration be made for each sample thickness. Several alternative routes for developing reliable microwave moisture sensors are discussed.

Description / Table of Contents: CONTENTS: Introduction. - Test materials. - Testing programs. - Test equipment. - Loading machine. - Environmental chamber. - Platen arrangements. - Stress/strain measurements. - Test procedures. - General. - Uniaxial compressive strength. - Diametral compression tests. - Stress/strain tests. - Test results. - Uniaxial compressive strength. - Brazil tensile strength. - Ring tensile strength. - Stress/strain characteristics. - Discussion. - Strength as a function of water content at room temperature. - Strength as a function of water content at -25°C. - Effect of temperature on the strength of nominally dry rocks. - Effect of low temperature on the strength of water-saturated rocks. - Effect of water on deformability at room temperature. - Deformability of air-dry rock as a function of temperature. - Effect of low temperature on the deformability of water-saturated rocks. - Conclusions and recommendations. - Literature cited. - Appendix A.Test materials for low temperature studies in rock mechanics. - Abstract.

Description / Table of Contents: Strength tests were made on three types of rock, both "air-dry" and water-saturated, at temperatures from +25° to -195°C, and stress/strain tests were made down to -60°C. Strength of air-dry specimens increased with decreasing temperature at an average rate of approximately 2 x 10^-3 °C^-1, and quasi-elastic moduli increased at comparable rates. Static fatigue mechanisms in air-dry rock were apparently influenced by temperature-modification of adsorbed water. Strength of water-saturated specimens increased dramatically as pore water froze, and continued to increase down to -120°C, where compressive and tensile strengths were greater than room temperature values by factors of 5, 4 and 2 for sandstone, limestone and granite respectively. Compressive stress/strain curves for saturated rocks became steeper after freezing, and initial tangent moduli for saturated high porosity rocks increased by well over an order of magnitude.

Description / Table of Contents: CONTENTS: Preface. - General introduction. - A. Pore water freezing data from differential thermal analysis. - Apparatus and technique. - Results. - Discussion. - Conclusions. - B. Indirect determination of pore water freezing data for rocks. - Air penetration tests. - Mercury penetration measurements. - Calculation of unfrozen water content and freezing point depression. - Comparison of calculated and measured freezing characteristics. - Conclusions. - C. Electrical conductivity measurements. - Procedures. - Results. - Discussion of results. - D. Thermal strains in cold rock. - Preliminary tests. - Recording dilatometer. - Test procedure. - Results. - Discussion. - Conclusions. - E. lsothermal compressibility of cold rocks. - Test method. - Test results. - Discussion of results. - Conclusion and recommendations. - General summary of results. - Literature cited. - Appendix A: Water adsorption. - Appendix B: Adsorption and absorption by Rochester shale. - Appendix C: Low temperature conductivity of saturated wood. - Abstract.

Description / Table of Contents: The phase composition of pore water in three types of rock subjected to temperature below 0°C was explored by a variety of techniques. Freezing point depression was measured as a function of water content by differential thermal analysis, the results yielding relationships between unfrozen water content and temperature. In an effort to avoid the practical difficulties involved in differential thermal analysis, attempts were made to determine freezing characteristics indirectly by air penetration and mercury penetration techniques applied at ordinary room temperatures. Electrical conductivity measurements were made as a function of temperature down to -195° C in an attempt to obtain information on characteristics of interfacial water films at low temperatures. Thermal strain was measured as a function of temperature in order to detect direct mechanical effects associated with phase changes, chiefly strain discontinuities brought about by volume changes in the pore water during rapid freezing and thawing. Finally, isothermal compressibility measurements, with pressures up to 27 kb, were made at - 10°C so as to determine whether the rock underwent step changes in volumetric strain at pressures corresponding to those of the phase boundaries for ice polymorphs.

Description / Table of Contents: CONTENTS: Introduction. - Summer temperature data. - Station network and history. - Parameters for data reduction. - Analysis of summer temperatures. - Temperature trends. - Summer temperatures in the highlands. - Lapse rates for summer temperatures. - Spatial variation of summer temperatures. - Summary. - Literature cited. - Appendix A. - Appendix B. - Appendix C. - Abstract.

Description / Table of Contents: Annual degree-day summations over bases of 43°F and 50°F in 15-day periods from May through August are given for the period of record for five interior Alaska climatic stations. Average temperature and precipitation data are included. Patterns of summer temperature in interior Alaska are analyzed in terms of historical, elevational and areal differences. Since 1900, summer temperatures show little long-term change but significant short-term changes. In contrast, winter temperatures show considerable fluctuations, which are reflected in mean annual temperatures to a much greater degree than are summer temperature fluctuations. Average summer lapse rates for the 1600 to 3300 and 3300 to 6600-ft levels were 3.4 and 3.7°F/1000 ft, respectively, based on timberline temperature observations and on upper air data from Fairbanks. Correlation analysis of daily and monthly average July temperatures indicates areas of uniformity with respect to temperature variation. This provides information on lowland climatic stations that are representative of highland locations, especially the Yukon-Tanana Uplands

Description / Table of Contents: CONTENTS: Introduction. - Background. - Physical characteristics of snow. - Mechanical behavior of snow. - Failure mechanism of snow. - Description of experimental work. - Method. - Preparation of test samples. - Test apparatus and equipment. - Procedure. - Results and discussion. - Mechanical properties of test samples. - Experimental results. - Summary, conclusions, and recommendations. - Literature cited. - Selected bibliography. - Appendix A. Development of theoretical equations. - Appendix B. Test data and calculations. - Appendix C. Selected, representative photographs. - Appendix D. Schedule of tests performed. - Abstract.

Description / Table of Contents: This report presents the results of a study performed on the behavior, particularly the deformation, of snow under a load applied to a rigid plate at a constant rate of penetration. The results will eventually be used in the development of design criteria for snow roads, runways, and foundations in the polar regions. The tests were conducted on snow samples having a high width/length ratio, simulating a two-dimensional case. The effect of snow density, plate size, and pressure on the deformation of snow below the load was investigated. The pressure-sinkage relationships and the bearing strength as functions of density were also investigated. It was determined that density, in the range 0.3 to 0.6 g/cm^3, can be used as a reasonably reliable index for predicting deformation and behavior of snow under load. In general, the critical pressure (bearing strength) increased as a power function of density, and critical sinkage decreased as a power function of density. It was also observed that the deformation bulb resembled the typical Boussinesq stress bulb. The experimental pressure-sinkage relationships agreed closely with recently developed theoretical values. For the range of plate sizes used, the test data did not provide conclusive evidence of the effect of plate size on deformation and bearing capacity of snow. The possibility of using the Moire fringe method for determing deformation patterns in snow and soils under various loading conditions should be investigated.

Description / Table of Contents: An infinite plate on an elastic foundation is considered for a uniform load distributed over a circular area. The analysis of the problem is based on three-dimensional theory of elasticity. A numerical evaluation for the critical stress is made assuming a bending type of failure and the results closely agree with Westergaard's equations.

Description / Table of Contents: From a geological perspective, gas hydrates are an important feature of the shallow geosphere. If current estimates are correct, gas hydrates contain more potential fossil fuel energy than is present in conventional oil, gas and coal deposits, although it is uncertain how much of this can be exploited. They are also geological agents that affect the physical, geophysical and geochemical properties of sediments. Oceanic gas hydrates are increasingly recognized as a major potential ha~rd for the stability of offshore structures in various deep-water hydrocarbon provinces. The possibility also exists that a large release of methane from gas hydrates may have a significant impact on the radiative properties of the atmosphere and thus influence global Climatei past~ present and future, Following an introduction and overviews, this book covers; analysis .and modelling of hydrate formation; exploration strategy and reservoir evaluation; regional case studies; relevance to margin~stability and climate change. Hydrate research informatiloln is presented from the USA, Russia, South Asia and the European Union. The individual papers, drawing on hydrate research: by leading :European and American scentists, are well written, with extensive references and high quality graphs and figures. Thorough index. Recommended as a valuable state,of-the-art reference in natural gas hydrates, marine geology, and the environment for students in all the earth science disciplines.

Description / Table of Contents: CONTENTS: Introduction. - Sampling. - Byrd Station. - Plateau Station. - Camp Century. - lnge Lehmann. - Grain-crystal relations. - Analytical techniques. - Thin sections. - Crystal size measurements. - Results and discussion. - Literature cited. - Appendix A: Crystal size as a function of depth and age in the Antarctic and Greenland ice sheets. - Abstract.

Description / Table of Contents: The growth of ice crystals as a function of depth and time in polar firn and glacier ice has been investigated at a number of locations in Antarctica and Greenland. Thin sections of snow and ice were used to measure crystal size variations which showed, in all cases, that crystal size increases essentially linearly with the age of samples. Crystal growth rates are strongly temperature dependent. At Camp Century, Greenland, where the firn temperature is -24°C, crystals grow approximately 23 times faster than at Plateau Station, Antarctica, where the in situ temperature is -57°C. Extrapolation of the existing data indicates that crystal growth rates in polar firn and ice could be expected to vary by about two orders of magnitude over the temperature range -60°C to -15°C. Examination of the changes in the pore-crystal structure relationships to a dpeth of 100 m at Camp Century shows that these changes closely resemble those occuring in the full-scale isothermal sintering of powder compacts.

Description / Table of Contents: CONTENTS: Introduction. - 1.The flow of organic nutrients in plants in cold-dominated ecosystems and the influence of man's activities on this flow. - Methodology for extraction and estimation of plant lipids, alcohol and water-soluble carbohydrates, starch and fructans. - Seasonal cycles in lipids and alcohol-soluble carbohydrates in plants at Barrow, Alaska. - Biochemical changes in plants at the heated soil experiment at Barrow. - Literature cited. - II. Contributions of carbon dioxide from frozen soil into the arctic atmosphere. - Introduction. - Laboratory study. - Field study. - Conclusions. - Literature cited. - III. Biochemical estimations of underground plant biomass. - Appendix A. Methodology. - Abstract.

Description / Table of Contents: Two approaches were used to study the carbon cycling in a cold-dominated ecosystem at Barrow, Alaska. One involved a detailed analysis of the flow of CO2 between the atmosphere, soil and biota and the other concentrated on the internal carbon cycling in plants. A pilot study was also conducted which investigated the possibility of estimating underground plant biomass by biochemical means. Both laboratory and field studies were conducted to analyze the input of CO2 to the arctic atmosphere by frozen tundra soils. Data are presented which indicate that frozen soil is a major source of CO2. It is hypothesized that CO2 trapped in soils during bi-directional freezing in the fall and winter is released during the spring thaw, thus producing a spring rise in CO2 content of the atmosphere. A procedure for the extraction and estimation of organic nutrients (lipids and carbohydrates) was developed and used to follow the seasonal cycle of these nutrients of plants obtained at Barrow, Alaska. No cycling in levels of carbohydrates (alcohol-soluble) was observed in the foliage during the season, however a definite cycling in lipid levels was seen for all the species studied. The species were synchronous. Plant survival and organic nutrient levels were followed during the winter over a heated-soil experiment at Barrow, Alaska. During the winter, the heating of the soil caused ponding which resulted in the elimination of Dupontia fischeri by mid-winter and the eventual death of all plants by spring. The carbohydrate levels indicated a starvation condition was created where a marked decrease in storage polymers (starch and fructans) occurred without a concurrent large increase in the alcohol-soluble carbohydrate levels. An increase in the fresh/dry weight ratios was also observed indicating etiolated, succulent growth in early winter. Four techniques were tried for estimating the below-ground biomass of plants. Two of these were eliminated as unsuitable, however two other methods(ATP and phospholipid-levels) remain to be fully evaluated.

Description / Table of Contents: CONTENTS: Preface. - Notation. - 1.Introduction. - 1.1Definition and scope of problem. - 1.2 Theoretical background. - 1.3 Previous work on the single plate-grouser problem. - 1.4 Background of the present investigation. - 2.Theory of two-dimensional soil failure by a plate-grouser. - 2.1 Basic criteria and assumptions. - 2.2 Rupture zones and boundaries. - 2.3 Forces in the spiral and Rankine zones. - 2.4 Solution to forces of the equilibrium wedge abc when [Theta]c 〉 [Theta] 〉 (- [Epsilon] [equal to or greater] -[Beta]). - 2.5 Solution to the forces H and V. - 3. Observation of soil rupture patterns. - 3.1 General. - 3.2 Test equipment and photographic technique. - 3.3 Photographing failure patterns. - 3.4 Observation of the equilibrium wedge when [Theta]c 〉 [Theta] 〉 - [Epsilon]. - 3.5 Rupture patterns at [Theta] = 90°. - 4. Force measurements. - 4.1Test program. - 4.2 The plate-grouser test apparatus. - 4.3 The measurement of soil strength. - 4.4 Results of controlled [Theta] tests. - 5. Conclusions. - Literature cited. - Appendix A: Details of mathematical methods. - Appendix B: Computer program. - Appendix C: Examples of application. - Appendix D: Photographs of failure patterns. - Abstract.

Description / Table of Contents: The most common example of the application of inclined loads to the soil is the plate-grouser. This consists of a strip footing with a vertical arm at one end. The most usual loading arrangement is one in which a fixed vertical load is applied and then the horizontal load is increased until failure occurs. A theory has been developed which will predict the maximum horizontal force, assuming that the soil is dense enough to be reasonably described by the Coulomb equation. The theory is based on slip line fields including wedges of soil that are not failing. These slip line fields vary systematically with the interface angle [Beta] and the angle of internal shearing resistance of the soil [Phi] and they are a function of the direction of motion of the interface [Theta]. A computer program is provided which will solve the problem directly if the direction of motion [Theta] is given. It will also solve the more practical situation described above by an iterative procedure. The postulated slip line fields have been shown to be correct by means of glass box photographs giving excellent agreement with the theory. The predictions of passive pressure have been verified by a series of force measurements on quite large grousers driven into saturated clay, dry sand and an intermediate loam.

Description / Table of Contents: CONTENTS: Preface. - Nomenclature. - Introduction. - Basic equations. - Equation of motion. - Equation of continuity. - Artificial viscosity. - Equation of state. - Equation of motion. - Equation of continuity. - Artificial viscosity. - Equation of state. - Finite difference approximation. - Equation of motion. - Equation of continuity. - Artificial viscosity. - Equation of state. - Boundary conditions. - Results and discussion. - Literature cited. - Abstract.

Description / Table of Contents: A finite difference method for predicting the effect of shock waves on a circular cylindrical cavity in elastic-plastic media was studied. A two-dimensional Lagrangean code was found quite satisfactory. Attenuation of the shock waves through the cavity and the deformation of the cavity wall were discussed.

Description / Table of Contents: CONTENTS: Introduction. - The ice/ice interface. - The ice/air interface. - The silicate/water/silicate interface. - The silicate/water/ice interface. - Summary. - Literature cited. - Abstract.

Description / Table of Contents: Interfacial regions in frozen soils are of the following types: ice/ice (grain boundary) ice/water/air, silicate/water/silicate (interlamellar) and silicate/water /ice (extralamellar). For the last, the mid-portion of the interfacial region should be regarded as a liquid-like solution of the ionic and undissociated substances sorbed by the interface and expelled from the ice during freezing. The interfacial forces operative in these regions result in distinct differences in the properties and behavior of the interfacial water, compared with water in bulk; but, in spite of strong interfacial forces, the interfacial water exhibits liquid-like mobility in its response to many kinds of driving forces. From the evidence and arguments considered, it is concluded that distinctly different zones of orientational order can be distinguished within the interfacial regions. For an advancing silicate/water/ice interface it is proposed that there is a zone of strong perturbation and disorder immediately proximate to silicate surfaces in which the protons of water molecules are partially delocalized; this makes them more easily dissociated. Two or three molecular diameters removed from the silicate surface the interfacial forces operative there combine to create a zone of enhanced order in the molecular configurations. At some farther distance, depending upon the temperature below freezing, it is suggested that there exists a disordered transition zone proximate to the ice surface as portrayed in Drost-Hansen's model. It is suggested that future investigations will contribute refinements in the model and will uncover still further complexities in the various interfaces mentioned.

Description / Table of Contents: This paper considers a load moving with a constant velocity across an ice sheet that is floating on water. The ice sheet is assumed to be an isotropic, elastic, thin plate extending to infinity. The water is assumed to be inviscous, incompressible, and of a constant depth. The dynamic equations describing this ice-water system are solved for the steady state solution. Both a concentrated load and a uniform load distributed over a circular area are considered. The velocity which causes resonance is determined. The deflection and stress directly under the load are numerically evaluated.

Description / Table of Contents: A theory is developed to describe the percolation of water through isothermal snow with a vertical porosity gradient. While the necessary laboratory experiments have not been done for snow, concepts from the general theory of two phase flow through porous media are used in the development. The general solution for the one-dimensional problem is given, which, when combined with any periodic boundary condition, can be used to make quantitative predictions. The theory is applied to water percolation through firn on the upper Seward Glacier (Sharp, 1951a). Using appropriate values for the parameters, theory shows a wave of volume flux which travels down into the firn and develops features similar to those observed by Sharp. These include an initially symmetric wave which distorts with depth, continuous (rather than intermittent) downward flow beneath the surface, and a decreasing value for the wave crest with depth. The rate at which the waves propagate is calculated using the method of characteristics and is in fair agreement with the observed rate where the permeability of the bulk firn with ice layers is reduced by a factor of two over homogeneous snow samples studied in the laboratory (Kuroiwa, 1963). The theory predicts that the waves advance with a shock front which grows with depth. The shock front is thought to be only an approximation to the actual physical process

Description / Table of Contents: CONTENTS: Preface. - Symbols. - Introduction. - Theory. - Darcy's Law. - Functional permeability. - Equations. - Characteristics. - Seward Glacier firn. - Discussion. - Summary. - Literature cited. - Abstract.

Description / Table of Contents: CONTENTS: Introduction. - What is a spline function?. - 1. Determination of a cubic spline. - 2. Effect of end conditions. - 3. Some properties of cubic splines. - Application to a lake temperature observation. - 1. Observed temperatures. - 2. Integral residuals of the observed temperatures. - 3. Theoretical temperature distributions. - Conclusion. - Literature cited.

Description / Table of Contents: Numerical differentiation by use of classical interpolation formulas yields a diversity of results. Consistent numerical differentiation can be performed by using a spline function as an interpolating function. As an application, temperature observed in a lake is numerically differentiated as a function of time and of depth by use of cubic splines. The deviation of the actual heat transfer mechanism from vertical heat conduction can thus be detected. The reliability of numerical differentiation by spline functions is manifest in this example.

Description / Table of Contents: The internal friction of single-crystal ice has been attributed to reorientation of the water molecule under periodic stress. However, the theory for damped dislocations, which offers another mechanism for the internal friction of ice, has not been investigated. The effects of scratching the surface of 41 ice samples and X-irradiating and plastically deforming them were evaluated. The effects observed on the internal friction of pure, single-crystal ice, in the flexure mode of oscillation between 400 and 1400 Hz, supported the existence of a dislocation-controlled mechanism, with the drag produced by the interaction of the dislocation with the protons in the crystal. In addition, analysis of the detailed shape of the data curve showed two peaks of tan delta as a function of temperature. The second peak, which had not been previously reported, had an activation energy of 0.16 eV and a relaxation time of 1.7 x 10^8 sec at infinite temperature. These experiments indicated that both peaks vrere controlled by the dislocation mechanism described above.

Description / Table of Contents: CONTENTS: Introduction. - Experimental procedure. - Results and discussion. - Derivation of unfrozen water contents from these results. - Literature cited. - Abstract.

Description / Table of Contents: Low temperature differential thermal analyses of selected clay-water systems were made to locate important phase change temperatures and to define fruitful temperature-pressure fields for precise calorimetric investigation. In addition to an exotherm corresponding to initial freezing, one, two or three exotherms were observed between -35°C and -60°C. The low temperature exotherms do not depend critically upon water content, but clearly they are related to clay mineral and exchangeable cation type. The evolution of heat in this temperature range probably corresponds to a phase change in the interfacial water.

Description / Table of Contents: CONTENTS : Introduction. - Basic analysis. - Part I: Far field surface motion. - A single oscillating source. - A group of forces over a finite area. - Part II: Near field study. - Motion at center of source. - Approximation of displacements. - Conclusion. - Literature cited. - Abstract.

Description / Table of Contents: Wave propagation generated by vibratory load on a homogeneous, isotropic, linear viscoelastic half-space is studied. The effect of a single concentrated force and a group of forces applied over a circular area has been examined and solutions of the displacement functions are presented. In the case of the group forces, the three types of force distribution used by Reissner and Sung were employed. At a great distance (far field) from the applied load, surface displacements are reduced to closed form expressions. A field method based on these results is recommended for determining the complex modulus and the damping property of a viscoelastic material. For areas near the source (near field), numerical procedures were employed to evaluate the integral solution. To facilitate the application, two simplified versions are provided for calculating the center displacement under the load. They both provide good approximation to the integral solution and, most important of all, they speed up the computation enormously

Description / Table of Contents: Although it has long been recognized that what ultimately drives metamorphism and metamorphic reactions is heat, what was less certain is the distribution of heat within the crust, the type and location of major heat sources and the rates of heat flux through crustal rocks. This book explores the factors that control metamorphism and rates of metamorphic processes.

Description / Table of Contents: The Mediterranean Region represents a complex mosaic of continental, microcontinental and ophiolitic terranes, whose overall evolution has been controlled by relative movements between the African and Eurasian plates. Deciphering the sequence of tectonic events in this region can be likened to attempting to reconstruct all the pictures in a stack of jigsaw puzzles when 90% of the pieces are missing (and the remaining 10% are no longer in their original shape!). Palaeomagnetic studies have played an important part in unravelling this 3D puzzle. The palaeomagnetic technique provides quantitative constraints on our reconstruction, since it can tell us which way each of the remaining pieces should be oriented (using magnetic declinations), their relative position with respect to the top of each picture (using magnetic inclinations), and in some cases which piece belongs to which picture (using magnetic dating). Perhaps more importantly, palaeomagnetism can also tell us something about the processes that led to the present confusion in our puzzle box. The 33 papers in this volume span the full width of the Mediterranean basin and present results from Permian to Quaternary rocks. Together they provide a snap-shot of the current state of palaeomagnetic research in the Mediterranean region. In addition to tectonic and magnetostratigraphic applications of palaeomagnetism, several contributions describe archaeomagnetic studies in the Mediterranean realm.

Description / Table of Contents: This book provides a synthesis of Archaean and Proterozoic crustal evolution in the North Atlantic Region. There is particular reference to Proterozoic collisional tectonics. The main topics include: Archaean crustal growth; Proterozoic crustal growth; orogenic processes during the Proterozic; geochronology of Proterozoic tectono-thermal processes; and provenance of Proterozoic sediments.

Description / Table of Contents: Microorganisms cause mineral precipitation and dissolution and control the distribution of elements in diverse environments at and below the surface of the Earth. Conversely, mineralogical and geochemical factors exert important controls on microbial evolution and the structure of microbial communities. This was the rationale for the Short Course on Geomicrobiology presented by the Mineralogical Society of America on October 18 and 19, 1997, at the Alta Peruvian Lodge in Alta, Utah. Minerals have been known and honored since humans realized their essential contributions to the "terra firma" and stone tools thrust our species on the path of cultural evolution. Microbes are the oldest living creatures, probably inhabiting at least a few salubrious environments on the earth as early as 3.8 billion years ago. At this moment in history we are only beginning to appreciate the intimate juxtaposition and interdependence of minerals and microbes. We have been nudged into this position by the realization that our earth is finite, and the recognition of many global environmental problems that minerals and microbes contribute to, both positively and negatively. In addition, our globe may not be the only site in the solar system where 'life' arose, or may persist. What all of these concerns enunciate is that we as scientists only dimly comprehend our own dynamic "terrestrial halls." This short course and volume have been generated with great enthusiasm for grasping as much as possible of the whole panorama of possibilities that involve both the inorganic and biologic realms . Over 3600 mineral species have been defined and their relationships to each other and the environments in which they form have been documented. This vast data base, collected over the past several hundred years and constantly added to and upgraded, is a monument to the research efforts of many geoscientists focused on the inorganic realm. Much of this data has come from investigators intrigued by the novelty, beauty, and versatility of minerals, direct expressions of the chemistry and physics of geologic processes. We are now adding a new dimension to questions of mineral formation, dissolution, and distribution: what were, are, and will be the contributions of microbes to these basic components of the environment. Microbes have also been known for hundreds of years. However, their small size (0.5 to 5 µm in diameter) and the difficulties associated with identifying a species unless it was grown in the laboratory (cultured), precluded thorough analysis. The advent of molecular biology has only recently made it possible to evaluate microbial evolutionary relatedness (phylogeny) and physiological diversity. These techniques are now being applied to study of microbial populations in natural environments. It is becoming very clear that the surface of Earth is populated by far more species of microbes than there are types of minerals. We are now exploring every portion of the globe and finding the relationships under the rubric "geomicrobiology." The ocean deeps are characterized by a diversity of microorganisms, including those associated with manganese nodules. The profusion and concentration of minerals created at ocean ridges and vents matches the variety of microorganisms, large animals, and plants there. The snowy tops of mountain ranges and glaciers of Antarctica harbor not just ice but whole bacterial communities whose cellular types and activities need elucidation. The equatorial jungles and the deserts, with their enormous diversity of ecological niches, further challenge us. The diversity of geographic, geologic, and biologic environments, including some contributed by humans (e.g. mines, air-conditioning equipment), can now also be explored in detail. Modern studies use protocols developed to preserve or measure in situ chemical and physical characteristics. Electron microscopes allow direct characterization of mineral and biological morphology and internal structures. Spectroscopic techniques permit complimentary chemical analysis, including determination of oxidation states, with very high spatial resolution. Other studies quantitatively measure isotopic abudances. These data serve to distinguish biologically mediated, or biologically controlled formation of the mineral from an abiotic process and mechanism. Each ecological niche requires accurate characterization of the mineralogic and biologic entities in order for us to begin to understand the range of dynamic relationships. We can pose many questions. Is the mineral only a substrate, or is its occurrence and stability impacted by microbiologic activity and metabolic requirements? Which minerals are of microbiological rather than inorganic origin and what are the mechanisms by which organisms dictate the morphology and structure of the solid phase formed? How do organic metabolic products bind metals and change their form and distribution, with implications for metal toxicity and geochemical cycles? How do inorganic reactions such as mineral dissolution and precipitation impact microbial populations through control of their physical and chemical environments? Clearly, new and excitingly research areas exist for all varieties of scientists. Although published by the Mineralogical Society of America, the authors of this volume include microbiologists, molecular biologists, biochemists, biophysicists, bioengineers as well as biomineralogists. Here, they bring together their respective expertise and perspectives to provide disciplinary and interdisciplinary background needed to define and further explore the topic of geomicrobiology. The volume is organized so as to first introduce the nature, diversity, and metabolic impact of microorganisms and the types of solid phases they interact with. This is followed by a discussion of processes that occur at cell surfaces, interfaces between microbes and minerals, and within cells, and the resulting mineral precipitation, dissolution, and changes in aqueous geochemistry. The volume concludes with a discussion of the carbon cycle over geologic time. In detail: Nealson and Stahl acquaint us with the basic properties of prokaryotes, including their size and structure. They define the types and ranges of microorganisms and their metabolisms and describe their impacts on some important biogeochemical cycles. Barns and Nierzwicki-Bauer document the phylogenetic relationships and evolution of microorganisms, begging some fundamental questions that might be now just beyond our grasp: What was the 'last common ancestor'? The physiology, biochemistry and ecology of hyperthermophilic, and the many diverse geologically important microbial species from the lithosphere and hydrosphere, as well as some of the techniques employed, are presented. Banfield and Hamers describe and integrate the processes acting on minerals and at surfaces relevant to microorganisms, examining the factors that control mineralogy, mineral forms, and the stability of phases. Surface properties and reaction rates for dissolution, precipitation, and growth of important classes of minerals are discussed. The possible role of mineral surfaces in formation of prebiotic molecules needed to explain the origin of life is examined. Little, Wagner and Lewandowski describe biofilms, an essential interface between microbes and minerals. They demonstrate that these membranes, with their unique morphological and structural attributes, are sites where much activity related to dissolution and/or formation of minerals takes place. Biology makes it possible to move molecules and elements against a gradient. Many questions regarding the transfer of elements from minerals to microbes at this important heterogeneous interface remain. Fortin, Ferris and Beveridge review surface-mediated mineral development by bacteria. Fresh or oceanic waters, anaerobic or aerobic environments provide discretely different ecologies, bacterial entities, and resulting mineralogies. It is obvious from this presentation that investigators have just scratched the surface of microbial mineralization processes. Bazlinski and Moskowitz review the magnetic biominerals and provide insights into the environmental and biological significance of these few tens of nanometer-sized mineral products. The magnetosome chemistry and biochemistry is probably the best understood of any biologically precipitated mineral. Their formation and unique properties underscore the roles these biomaterials play in the rock magnetic record and in geochemical cycles. Tebo, Ghiorse, van Waasbergen, Siering and Caspi contribute data on the roles of Mnminerals and Mn(II) oxidation in geologic environments. Their chapter encompasses molecular genetic and biochemical investigations. Manganese oxides and oxyhydroxides are notoriously difficult to identify and the crystal chemistry of these phases is a research effort on its own. The prospect of learning how microbes utilize the multiple oxidation states of Mn (2+, 3+ and 4+) as a source of energy sharpens the motivation for interdisciplinary study. Manganese is also known as a cofactor in the production and activation of the enzymes that digest large biomolecules that must be the source of the smaller molecular species and ultimately the building blocks of C, N, 0, H required by all species. How have the mechanisms identified in the bacterial systems been transferred up the phylogenetic tree to plants and humans? This is an expanding and intriguing area for further investigation. DeVrind-de Jong and de Vrind address silicate and carbonate deposition by algae (eukaryotic photosynthetic microorganisms). This chapter documents the mechanisms of biomineralization of diatoms and coccoliths. These abundant aquatic organisms are responsible for huge volumes of siliceous sediments and calcium carbonate deposits world wide. The implications of algal biomineralization for climatic variation throughout much of the Earth's history may be quite significant. Stone leads us though a quantitative approach to evaluating reactions between organic molecules and cations. He considers available extracellular organic ligands and the roles these play in uptake of metals. He documents the basic chemical speciation and complexation for several elements, making metal to metal comparisons. Remaining challenges involve coordinating the organic and inorganic results of biologic activity. Following the discussion of biomineralization and interactions between organic compounds and cations, Silver discusses the strategies microorganisms have evolved to deal with toxic metal concentrations in solution. Beyond the fundamental biological significance, this has important implications for understanding microbial populations in contaminated environments. The impact on the geochemical form (speciation) and distribution of elements is also discussed. Nordstrom and Southam summarize sulfide mineral oxidation and dissolution kinetics and devote considerable effort to describing the specific contributions of microorganisms, mostly bacteria. Despite the vast amount of accumulated information, many unanswered questions remain. Barker, Welch and Banfield address weathering of silicate minerals. This topic encompasses not only mineralogy but geomorphology, microbiology, and geochemistry. The necessary interdisciplinary mode of these investigations is highlighted by discussion of the role(s) of bacterial nutrition, groundwater chemistry, and biochemistry. There are obvious implications for hazardous waste storage, a currently daunting and politicized topic that requires predictions over thousands to millions of years. Finally, Des Marais treats the long term evolution of the carbon cycle, adopting a biogeochemical view. He discusses the sources, sinks and the transfer of the element over geologic time. Consideration of such a basic series of questions relating to the partitioning of carbon necessitate interdisciplinary crossovers. It is a fitting conclusion to a dialogue in progress.