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Investigation Of Ambient Seismic Noise Using Seismic Interferometry In The Midwestern United States, Joshua Dakota Boschelli

Open Access Theses

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 …

Seismic Body-Wave Interferometry Using Noise Autocorrelations For Crustal Structure And A Tutorial On 3d Seismic Processing And Imaging Using Madagascar, Can Oren

Open Access Theses

Seismic body-wave interferometry is applied to selected seismic stations from the USArray Earthscope Transportable Array (TA) by autocorrelating ambient seismic noise recordings to construct effective zero-offset reflection seismograms. The robustness of the auto-correlations of noise traces is first tested on a TA station in Nevada where body-wave reflections similar to those found in an earlier study are identified. This approach is then applied to several TA stations in the central U.S., and the results are compared with synthetic data. Different stacking time periods are then examined to find the shortest time intervals that provide stable correlation stacks.

A tutorial on …

Callovian (Upper Middle Jurassic) Magnetostratigraphy: A Composite Polarity Pattern From France, Britain And Germany, And Its Correlation To The Pacific Marine Magnetic Anomaly Model, Rachel Anne Gipe

Open Access Theses

Callovian strata from sixteen exposures across western Europe produced a nearly continuous composite geomagnetic polarity reference sequence spanning the latest Bathonian (Clydoniceras discus Zone) through the entire Callovian and into the earliest Oxfordian (Quenstedtoceras mariae zone). This sequence is compiled from multi-section sequences from France and England, a section in southern Germany, and a section on the Isle of Skye (Scotland). These sections are calibrated with ammonite biostratigraphy, brachiopod associations and sequence stratigraphy. Over 400 oriented core samples were subjected to progressive thermal demagnetization and filtered according to magnetic behavior; the highest quality suite produced mean paleopoles of 67.3°N, 174.8°E …