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Full-Text Articles in Geophysics and Seismology
Investigating The 2016 Jackson, Wyoming Earthquake Sequence Using Waveform Cross-Correlation And Seismic Array Methods, Emily Jo Graves
Investigating The 2016 Jackson, Wyoming Earthquake Sequence Using Waveform Cross-Correlation And Seismic Array Methods, Emily Jo Graves
Open Access Theses & Dissertations
During a visual inspection of PDAR data extracted for the catalog events, I observed additional, unreported events, which is to be expected during an energetic swarm or seismic sequence. The casual observation of missed events strongly implied that more such missed events could be found in the data, which could improve the completeness of the earthquake catalog for the Jackson, Wyoming area. Catalog completeness improves our assessment of a region's tectonic behavior and earthquake exposure. To search for recurring swarm or earthquake sequence behavior, I applied waveform correlation methods to scan nearly two decades of continuous PDAR waveforms, comparing to …
Analysis Of Shallow Seismicity And Stress Fields In Southeastern Alaska, Hugo Rodriguez
Analysis Of Shallow Seismicity And Stress Fields In Southeastern Alaska, Hugo Rodriguez
Open Access Theses & Dissertations
Southeastern Alaska is dominated by strike-slip motion along the Queen Charlotte-southern Fairweather fault system (QCFS) in the south and transitions to oblique convergent motion partitioned between strike-slip motion along the Denali and northern Fairweather fault systems and thrusting along faults of the St. Elias region. Geologic complications are further increased by the subduction of the Yakutat microplate beneath North America and glacial processes. By studying regional background seismicity we intend to better determine the current state of stress of southeastern Alaska from the Dixon Entrance to Yakutat Bay. Phase data was gathered for over 4000 earthquakes of depths <20 km and magnitude <5 that occurred from 1973-2005 from Alaskan and Canadian databases. We relocated these earthquakes using the Double-Difference joint hypocenter method. Two areas of interest were identified with high concentrations of seismicity after relocation calculations for the entire southeast Alaska region; Glacier Bay through Yakutat (GBY) and the area surrounding Mt. Ogden (MOG). Earthquake locations in GBY are diffuse with some isolated clusters. The MOG subregion is dominated by a large northeast to southwest trending cluster that trends along the Speel River. We used these relocations and first motion data to estimate the stress fields for earthquake clusters that formed. Only a few of the calculated stress tensors were successful in representing the region's overall tectonic signature. We combined the calculated stress information with GPS, magnetic and gravity data in order determine how plate motion is partitioned in this region and to identify other potentially active faults.