The electrical conductivity of the pyromagmas from the Northeast Crater of Mount Etna, Sicily was measured over the temperature range 1032°C to 1071°C and over the frequency range 1 kHz to 400 kHz. Measurements were made using a four-terminal Wenner array in conjunction with a Wavetek Model 110B portable signal generator and Hewlett Packard Model 731 portable electronic voltmeters. The electrical conductivity is of the order of 0.4 mhos/m with less than 20% dispersion over the frequency range. Over the 40 degree temperature interval the temperature coefficient of resistance corresponds to an activation energy of 1.5 ± 0.5 eV. The value for the electrical conductivity of the gas-charged pyromagma is related to values determined in the laboratory for gas-free melts of lava and for glasses and slags of similar chemical composition. An original design of semi-expendable graphite-molybdenum electrode contributed greatly to the reliability of the measurements. A chromatographic analysis of the vent gases, and a silicate analysis, a modal analysis and a normal analysis of the lavas are included for completeness. Finally, as an aid to future electromagnetic probing activity, an analysis and estimate are made of the variation of electrical conductivity of pyromagma with depth in a volcanic conduit. / Graduation date: 1970

Graduation date: 2002

Rock glaciers are dynamic landforms and, as such, exhibit interesting and welldeveloped structural features, which translate to surface morphology in the form of ridges and furrows. These distinguishing features have led researchers to study the physics behind the movement and internal deformation of rock glaciers. For years researchers had no access to the internal makeup of rock glaciers. Thus, proposed models and discussion have been based on theoretical concepts of electromagnetic (EM) wave propogation. With the application of ground penetrating radar (GPR) to provide a view of the interior structure of a rock glacier, researchers had “real” data to verify their models. However, no comparison has been made between a GPR profile and an actual cross-section of a rock glacier. The purpose of this thesis is to validate the fidelity of GPR in showing the actual structure of a rock glacier. A trench that was excavated through the toe of a rock glacier on Mount Mestas in south central Colorado provided a view of the actual structure of the landform. The structure in the trench was compared with GPR and EM data. The GPR study was conducted using a PulsEKKOTM 100A subsurface imaging radar with 25, 50, and 100 MHz antennas, to detect dielectric contrasts within the rock glacier. A frequency domain EM34 by Geonics LtdTM was also used to supplement the GPR data by measuring the rock glacier’s conductivity at various depths. This thesis proved, by utilizing statistics, that GPR is a useful tool in visualizing the interior structure of rock glaciers. The 100 MHz antennas clearly show small scale reflection horizons caused by changes in clast orientation and subsurface material composition. These events coincide with structures seen in the trench. Individual clasts greater than 0.375 m were also recognized as point sources in the GPR profiles. Large continuous bedding layers were observed with the 25 and 50 MHz antennas, which reflect the structure seen in the trench. A large scale thrust fault was also located with the GPR. However, this was not visible in the panoramic photograph because the fault occurs below the base of the trench.

Thesis (Ph. D.)--Brigham Young University. Dept. of Sociology, 2004. / Includes bibliographical references (p. 162-178).

Thesis (D.M.A.)--University of Texas at Austin, 2003. / Supervisor: Donald Grantham. Vita. Includes bibliographical references. Available also from UMI Company.

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Thesis (M.A. in Theological Studies)--Associated Mennonite Biblical Seminary, 1996. / Includes bibliographical references (leaves 94-100).

Thesis (Ph. D.)--University of Washington. / Bibliography: l. [139]-143.