IMAGING THE MOHO BENEATH THE SOUTHERN APPALACHIANS USING GLOBAL SEISMIC PHASES RECORDED BY THE SESAME BROADBAND ARRAY

Global-phase seismic interferometry (GloPSI) is a seismic method that allows for the extraction of zero-offset reflections generated by reverberated seismic phases. This study utilizes the GloPSI method, using the global seismic phase PKIKP as a virtual source to generate reflection profiles along three survey lines of the Southeastern Suture of the Appalachian Margin Experiment (SESAME) array. The SESAME array consisted of 85 broadband seismometers deployed along three survey lines that parallel Consortium for Continental Reflection Profiling (COCORP) lines: a north-south trending line (W) extending from the Blue Ridge Mountains of western Georgia south to Florida, a north-south trending line (E) extending across the Coastal Plain of eastern Georgia and Florida, and a northwest-southeast trending line (D) extending across the Valley and Ridge, Blue Ridge, Inner Piedmont, and Carolina Terrane. This study investigates structure of the continental lithosphere and asthenosphere, particularly in relation to Paleozoic collisional tectonics and Mesozoic rifting. Additionally, through experimentation with deconvolution and autocorrelation techniques, we investigate the structure, nature, and seismic response of sediments from the Coastal Plain province, an area that has been known to be plagued by seismic reflection multiples as well as other complications. Through the use of low frequency images, this study serves to supplement the COCORP reflection profiles from the area. Earthquakes for analysis were selected on four fundamental criteria: source to receiver distances between 115 and 180 degrees, excluding distances between 145 - 160 degrees due to the interfering arrival of the seismic phase PKP, earthquake moment magnitudes ranging from 6.0 – 7.2, earthquake event depths of at least 50 km, and reasonably high initial signal to noise within the earthquake trace. The result of this study is the generation of three reflection profiles D, W, and E with approximate lengths of 350, 550, and 400 kilometers respectively, which provide reflection responses of the Moho over a wide range of frequencies to detail the crust-mantle transition and provide insight into the geologic history of the provinces.