Many factors such as rift history, crustal structure and distribution of high thermal conductivity salt bodies throughout the sediment pile affect the present day thermal structure of the deepwater Scotian Slope. Understanding the basin's thermal evolution is crucial in determining the hydrocarbon maturation potential of this deepwater frontier basin. The Late Jurassic Verrill Canyon Formation of the deepwater slope has been inferred as the primary source rock interval for the Scotian Basin. However, to date, only twelve boreholes have sampled the Scotian Slope, and of these, none penetrate beneath the uppermost Jurassic sediments. Therefore, the distribution and maturation of deeper source rock intervals through standard vitrinite reflectance analysis remains unknown. In this study we attempt to better constrain the thermal history and maturation potential of the central Scotian Slope using a combination of recently acquired seafloor heat flow data, 2D seismic reflection data, available well data, simple lithospheric rift models and 3D thermal and petroleum systems modelling. We have derived a method of combining seafloor heat flow data with simple lithospheric rift models to provide first order constraints on the hydrocarbon maturation potential of frontier basins in dynamic 3D thermal models for regions lacking vitrinite reflectance and temperature data from boreholes. In July 2008, 47 seafloor heat flow measurements were acquired across the central Scotian Slope in an attempt to better constrain the region's thermal structure. Locations seaward of the salt diapiric province, thus unaffected by the high thermal conductivity of salt, recorded seafloor heat flow values of ~41-46 mWm-2. Significant increases in seafloor heat flow were noted for stations overlying salt diapiric structures, reaching values upwards of 72 mWm-2. The seafloor heat flow data have been corrected to remove the conductive effects of salt and the cooling effects of seafloor sedimentation on measured heat flow. The corrected data are compared with basal heat flux predictions from simple lithospheric rift models as constrained using crustal ( ) and lithospheric ( ) stretching factors after Wu (2007) to constrain heat flux history through time. Seafloor heat flow and simple modelling results suggest present day basal heat flux does not vary significantly across the slope. Present day basal heat flux across the central Scotian Slope is ~44-46 mWm-2. Basal heat flux curves from simple lithospheric rift models are used to constrain the heat flux history in 3D thermal and petroleum systems models of the central Scotian Slope. Numerous basal heat flux histories were tested to determine which heat flux history yielded the best match between modelled and measured seafloor heat flow data and to determine how varying basal heat flux affects the modelled hydrocarbon maturation of Verrill Canyon source rocks. The basal heat flux history which yielded the best match to measured seafloor heat flow data suggests that the Late Jurassic source rock interval rests primarily within the late oil window. Variations in radiogenic heat production across the margin associated with thickening continental crust were tested and suggest that significant variations in both maturation and seafloor heat flow may occur if radiogenic heat producing elements occur in high enough concentrations in the crust.

Sensible heat flux, a key component of the surface energy balance, is difficult to estimate in practice. This study was conducted to see if backpropagation neural networks could estimate sensible heat flux by using horizontal wind speed, air temperature, radiometric surface temperature, net radiation, and time as input. Ground measurements from the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE), collected in 1987 and 1989 over a prairie grassland in Kansas, were used for network training and validation. Networks trained on part of the data from a narrow range of space-time coordinates performed well over the other part, with error (root mean square error divided by mean of observations) values as low as 0.24. This indicates the potential in neural networks for linking sensible heat flux to routinely measured meteorological variables and variables amenable to remote sensing. When the networks were tested with data from other space-times, performance varied from good to poor, with average error values around 1.26. This was mainly due to lack of input variables parameterizing canopy morphology and soil moisture, indicating that such variables should be incorporated in the design of future networks intended for large scale applications.

Thesis (M.Sc.) - Carleton University, 2002. / Includes bibliographical references (p. 100-104). Also available in electronic format on the Internet.

Thèse (D.R.M.)--Université du Québec à Montréal, 1999. / Bibliogr.: f. 176-197. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph.D.)--Memorial University of Newfoundland. / Typescript. Bibliography: leaves 151-157. Also available online.

No description available.

Abstract Knowledge of the thermal conditions in the lithosphere is based on theoretical models of heat transfer constrained by geological and geophysical data. The present dissertation focuses on the uncertainties of calculated temperature and heat flow density results and on how they depend on the uncertainties of thermal properties of rocks, as well as on the relevant boundary conditions. Due to the high number of involved variables of typical models, the random simulation technique was chosen as the applied tool in the analysis. Further, the random simulation technique was applied in inverse Monte Carlo solutions of geothermal models. In addition to modelling technique development, new measurements on thermal conductivity and diffusivity of middle and lower crustal rocks in elevated pressure and temperature were carried out. In the uncertainty analysis it was found that a temperature uncertainty of 50 K at the Moho level, which is at a 50 km's depth in the layered model, is produced by an uncertainty of only 0.5 W m-1 K-1 in thermal conductivity values or 0.2 orders of magnitude uncertainty in heat production rate (mW m-3). Similar uncertainties are obtained in Moho temperature, given that the lower boundary condition varies by ± 115 K in temperature (nominal value 1373 K) or ± 1.7 mW m-2 in mantle heat-flow density (nominal value 13.2 mW m-2). Temperature and pressure dependencies of thermal conductivity are minor in comparison to the previous effects. The inversion results indicated that the Monte Carlo technique is a powerful tool in geothermal modelling. When only surface heat-flow density data are used as a fitting object, temperatures at the depth of 200 km can be inverted with an uncertainty of 120 - 170 K. When petrological temperature-depth (pressure) data on kimberlite-hosted mantle xenoliths were used also as a fitting object, the uncertainty was reduced to 60 - 130 K. The inversion does not remove the ambiguity of the models completely, but it reduces significantly the uncertainty of the temperature results.

An Fourier Series solution is presented that describes the simultaneous, one-dimensional, vertical flow of heat and ground water in homogeneous, porous media beneath streams. Use of this analytical solution provides an indirect method of determining vertical flow rates and the effective vertical hydraulic connection between sediments and overlying streams. The method consists of varying the Darcy velocity in the solution until the temperature profiles predicted by the solution match those measured in the field. The method was applied at three field sites in Central Massachusetts. At the first site, which is underlain by lacustrine clay, the vertical flow rate through the clay was determined to be less than 5x10⁻⁷ cm/s and the vertical hydraulic conductivity was less than 0.08 cm/s. The vertical flow rate through mixed sand and gravel underlying the second site equaled 7.5x10⁻⁶ cm/s and vertical hydraulic conductivities of sediments underlying the site ranged from 3.8x10⁻⁴ to 3.1x10⁻³ cm/s. The vertical flow rate through mixed sand and gravel underlying the third site ranged from 3x10⁻⁵ to 7x10⁻⁵ cm/s and vertical hydraulic conductivities of sediments underlying the site ranged from 1x10⁻³ to 4x10⁻³ cm/s. The simultaneous flow of heat and ground water in sediments beneath streams may be more complex than that assumed for the Fourier Series solution. The additional complexity may be partially attributable to two factors: the presence of horizontal ground-water flow, and the presence of thermal conditions near the stream that differ from conditions in the stream itself. The effects of that these two factors have on thermal regimes in sediments beneath streams were investigated using numerical simulations. Results indicate, for example, that under conditions of no horizontal ground-water flow, thermal conditions near the stream can affect temperatures in sediments beneath the stream as far as 900 cm from the stream bank. For horizontal flow rates greater than about 1x10⁻⁴ cm/s, thermal conditions near the stream can affect temperatures in sediments beneath the stream as far as 1500 cm from the stream bank. The method of determining flow rates and hydraulic connection has been applied to stream-aquifer systems. However, the method also may have application in other hydrologic settings. Two such applications might be to determine flow rates to and from lakes and rates of recharge to aquifers.

This research describes a two-dimensional modelling effort of heat and mass transport in simplified intrusive models of sills and their feeder dykes. These simplified models resembled a complex intrusive system such as the Great Dyke of Zimbabwe. This study investigated the impact of variable geometry to transport processes in two ways. First the time evolution of heat and mass transport during cooling was investigated. Then emphasis was placed on the application of convective scavenging as a mechanism that leads to the formation of minerals of economic interest, in particular the Platinum Group Elements (PGEs). The Navier-Stokes equations employed generated regions of high shear within the magma where we expected enhanced collisions between the immiscible sulphide liquid particles and PGEs. These collisions scavenge PGEs from the primary melt, aggregate and concentrate it to form PGEs enrichment in zero shear zones. The PGEs scavenge; concentrate and 'glue' in zero shear zones in the early history of convection because of viscosity and dispersive pressure (Bagnold effect). The effect of increasing the geometry size enhances scavenging, creates bigger zero shear zones with dilute concentrate of PGEs but you get high shear near the roots of the dyke/sill where the concentration will not be dilute. The time evolution calculations show that increasing the size of the magma chamber results in stronger initial convection currents for large magma models than for small ones. However, convection takes, approximately the same time to cease for both models. The research concludes that the time evolution for convective heat transfer is dependent on the viscosity rather than on geometry size. However, conductive heat transfer to the e-folding temperature was almost six times as long for the large model (M4) than the small one (M2). Variable viscosity as a physical property was applied to models 2 and 4 only. Video animations that simulate the cooling process for these models are enclosed in a CD at the back of this thesis. These simulations provide information with regard to the emplacement history and distribution of PGEs ore bodies. This will assist the reserve estimation and the location of economic minerals.

First, I attempt to present a unified approach to the study of transport phenomena in multicoponent anisotropic space plasmas. In the limit of small temperature anisotropies this system of generalized transport equations reduces to Grad's 13-moment system of transport equations. In the collisionless limit, the generalized transport equations account for collisionless heat flow, cillisionless viscosity, and large temperature anisotropies. Also, I show that with the appropriate assumptions, the system of generalized transport equations reduces to all of the other major systems of transport equations for anisotropic plasmas that have been derived to date. Next, for application to aeronomy and space physics problems involving strongly magnetized plasma flows, I derive momentum and energy exchange collision terms for interpenetrating bi-Maxwellian gases. Collision terms are derived for Coulomb, Maxwell molecule, and constant collision cross section interaction potentials. The collision terms are valid for arbitrary flow velocity differences and temperature differences between the interacting gases as well as for arbitrary temperature anisotropies. The collision terms have to be evaluated numerically and the appropriate coefficients are presented in tables However, the collision terms are also fitted with simplified expressions, the accuracy of which depends on both the interaction potential and the temperature anisotropy. In addition, I derive the closed set of transport equations that are associated with the momentum and energy collision terms. Finally, I study the extent to which Maxwellian and bi-Maxwellian series expansions can describe plasma flows characterized by non-Maxwellian velocity distributions, with emphasis given to modeling the anisotropic character of the distribution function. The problem considered is the steady state flow of a weakly-ionized plasma subjected to homogeneous electric and magnetic fields, and different collision models are used. In the case of relaxation collision model, a closed form expression is found for the ion velocity distribution function, while for more regorous models (polarization and hard sphere) I have to use the Monte Carlo simulation. These provided a basis for determining the adequacy of a given series expansion. I find that, in general, the bi-Maxwellian-based expansions for the velocity distribution function is better suited to describing anisotropic plasmas than the Maxwellian-based expansions. (166 pages)