Date of Award


Degree Type


Degree Name

Master of Science (MS)


Earth, Atmospheric, and Planetary Sciences

First Advisor

Hersh J. Gilbert

Committee Chair

Hersh J. Gilbert

Committee Member 1

Robert L. Nowack

Committee Member 2

Kenneth D. Ridgway


The portion of the North American craton occupied by the Midwestern United States is a cratonic platform, where a veneer of Phanerozoic sedimentary strata buries the Precambrian basement up to 7 km. Due to the sediment cover and low topographic relief, the at depth structure of the region remains poorly understood. This region is of particular interest because over the past half-billion years tectonic forces have resulted in the formation of epeirogenic provinces in a stable cratonic interior. Using the OIINK flexible seismic array and the Earthscope Transportable Array, Ambient Seismic Noise Tomography was applied to investigate the crustal structure and produce high-resolution structural models of the region. For our analysis we used the vertical component of seismograms recorded between January 2011 and December 2014, where spurious events were filtered out to establish the background seismic noise of the region. Seismic observations based on the cross-correlations of seismic noise from 46,665 station pairs were used to obtain phase velocities at periods from 4 to 40 s. From these measurements a high resolution model was formed, improving the our understanding of the complex basement geology of the Midwestern United States.