Geophysics and Seismology Commons^™

Electrical Resistivity Of Nickel, Iron And Iron-Silicon Alloy Melts At High Pressure With Implications For The Thermal Conductivity Of The Earth’S Core, Reynold E. Silber

Electronic Thesis and Dissertation Repository

The Earth’s liquid outer core (OC) is composed of Fe alloyed with up to 10% Ni and a small fraction of light elements. However, the effect of light elements such as Si on the transport properties of liquid Fe-alloy in Earth’s OC is not clear. Thermal conductivity (κ) and related electrical resistivity (ρ) are the least constrained parameters in OC. Therefore, the characterization of transport properties of Ni, Fe and Fe-Si at high pressure has important geophysical implications for the Earth’s core. The ρ of solid and liquid Ni, Fe and Fe 4%Si was measured at …

Robust Earthquake Site Classification Assessment At Ontario Bridge Sites., Alex Bilson Darko

Electronic Thesis and Dissertation Repository

Canadian seismic design guidelines classify subsurface ground conditions based on the average shear-wave velocity (V_S) of the upper 30 meters (V_S30). We seek to optimize a robust earthquake site classification procedure for Ontario bridge sites, assessed primarily from blind comparison of non-invasive V_S depth profiling techniques. Non-invasive seismic testing is performed at 10 bridge sites in southern Ontario co-located with invasive penetration and/or borehole V_S measurements. Non-invasive surface wave dispersion and site amplification functions are jointly inverted to retrieve V_S profiles at each site. A general correlation between corrected V_S and cone …

Empirical Characterization Of Induced Seismicity In Alberta And Oklahoma, Mark Novakovic

Electronic Thesis and Dissertation Repository

This thesis characterizes ground motions from induced seismic events in Alberta and Oklahoma, following an overall methodology that uses ground-motion recordings to calibrate the parameters of a seismological model. This body of work is carried out in three related studies.

In the first study, we perform a preliminary evaluation of ground motions in Alberta using thousands of observations of natural, induced and blast events of magnitude 1 to 4, recorded on a newly-deployed regional seismograph array. We evaluate the applicability of a moment magnitude (M) estimation algorithm for the events and compare the observed ground motions with expectations …

Impact Craters On Titan: Finalizing Titan's Crater Population, Joshua E. Hedgepeth

Electronic Thesis and Dissertation Repository

Titan is one of the most dynamic moons in the solar system. It is smaller than Earth and much colder, yet Titan is eerily similar to Earth, with rivers, rain, and seas, as well as sand seas that wrap around the equator. However, the rivers are made of hydrocarbons rather than water and the sand made of organics rather rock. We can use Titan’s impact craters to study how these processes modify the surface by comparing the craters depths, diameters and rim heights of Titan’s craters with fresh craters. Therefore, we have used the complete data set from NASA’s Cassini …

Geomechanical Modelling Of Induced Seismicity, Bodi Zhao

Electronic Thesis and Dissertation Repository

In recent years, there has been a dramatic increase in seismicity (earthquakes) due to anthropogenic activities related to the unconventional oil and gas exploration in the Western Canada Sedimentary Basin (WCSB) and the central U.S. There are compelling evidences that hydraulic fracturing and wastewater injection operations in those areas play a key role in induced seismicity. To better understand the physical mechanisms involved, this thesis aims to explore the mechanisms responsible for occurrence of induced earthquakes: mainshock-aftershock triggering mechanism and poroelastic response. In the first approach, the obtained results indicate the relationship between the Coulomb stress changes after 4 moderate …