Seismic refraction measurements along two unreversed lines indicate that the earth's crust is 26 km thick in southeastern Alaska and 30 km thick along the Inside Passage of British Columbia. The crust in southeastern Alaska, north of Dixon Entrance, consists of a layer 9 km thick with a seismic velocity of 5.90 km/sec, a layer 7 km thick with a seismic velocity of 6.30 km/sec. and a layer 10 km thick with a seismic velocity of 6.96 km/sec. The crust along the Inside Passage of British Columbia, south of Dixon Entrance, consists of a layer 13 km thick with a seismic velocity of 6.03 km/sec, a layer 5 km thick with a seismic velocity of 6.41 km/sec, and a layer 12 km thick with a seismic velocity of 6.70 km/sec. The velocity of the mantle below the M discontinuity is 7.86 km/sec in southeastern Alaska and 8.11 km/sec in British Columbia. A compilation of Bouguer gravity data along the Inside Passage from northern Vancouver Island to northern southeastern Alaska indicates near-zero anomalies between steep gradients offshore and near the western margin of the Coast Mountains. A two-dimensional gravity model, constrained by seismic refraction measurements, suggests that the thickness of the crust is constant beneath the region of near-zero gravity anomalies and indicates a step-like transition between oceanic and continental structure. Seismic reflection, gravity, and magnetic measurements, obtained during a 1970 cruise of the R/V Yaquina, help to determine upper crustal structures in Dixon Entrance. Gravity models, constructed to agree with these data and the measurements of previous investigators, indicate sediment thicknesses of nearly 3 km east of Learmonth Bank and west of Celestial Reef. Magnetic models suggest large lateral changes in basement susceptibility. Either highly metamorphosed rock or basaltic intrusions can account for these changes in susceptibility. Folded sediments suggest post depositional distortion due either to regional compression or to major local intrusions. Several linear gravity features, observed in northern Dixon Entrance, disappear north of Graham Island. Either the structures responsible for the gravity features end or thick layers of basalt, extending northward from Graham Island, obscure the effect of the structures. A single-station survey detected microearthquakes at nine locations in western British Columbia and southeastern Alaska. The majority of the observed distant microearthquakes probably originated in the Queen Charlotte Islands fault zone. However, observed nearby microearthquakes indicate a microearthquake seismicity of several events per day along the mainland coast of British Columbia. Temporary seismic arrays located at a site along the central portion of Chatham Strait near the Chatham Strait fault and at a site in Glacier Bay recorded few nearby microearthquakes. Arrivals at the arrays permitted the location of distant microearthquakes, however, with epicenters in the vicinity of northern Lynn Canal and along the Fairweather fault. / Graduation date: 1972

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 96-97). Also available via the Internet.

No description available.

No description available.

Thesis (Ph. D.)--University of New South Wales, 2001. / Also available online.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 176-181).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 37-38).

M.Phil. (Optometry) / An investigation of the nature of variability or variation of refractive behaviour (in a sample of universi ty students studying optometry) is described. Measurements of refractive behaviour were obtained by means of autorefraction. This study was based upon multivariate methods of statistical analysis which have only recently become available in optometric science. Variation is examined using both quali tative and quanti tative methods including stereo-pair scatter plots, confidence and distribution ellipsoids, trajectories of change of dioptric power, meridional profiles, testing of hypotheses on means and variance-covariance, and graphs which represent the type of uniform variation in a 2-dimensional plane known as the i)-plane. These methods are of great assistance in developing an understanding of the nature of the variation shown, as well as, in developing an awareness of the distribution or spread of the population from which the sample was drawn. Analyses of variability of refractive behaviour on both an artificial, or test eye, and on several individual human eyes are also described. The significance of some important aspects of variabili ty of refractive behaviour involving normality and departures therefrom (such as results from outliers) are discussed and illustrated by means of examples. Distributions were found in which more than one mode was present (polymodal or multimodal behaviour). Distributions were also observed to vary from having an almost spherical spread of measurements (of refractive behaviour) to having a spindle or rod-like spread of measurements instead...