In this dissertation we analyze plasma sheet magnetic field and plasma data observed during varying levels of auroral activity from very small, isolated events known as pseudobreakups to large, global events known as substorms. The plasma and magnetic field data are taken from instruments onboard the WIND spacecraft while it ...

The geometry of the subducting Juan de Fuca plate beneath the Olympic Peninsula of Western Washington is modeled using wide-angle P mP reflections off the slab Moho. Active-source reflection data collected from the 1998 WET SHIPS project were augmented with earthquake-source reflections to increase the spatial distribution ...

Infrasonic signals provide a valuable tool for the study of volcanic eruptions because volcanoes generate the majority of their acoustic energy in the infrasonic bandwidth and infrasound is only slightly affected by propagation filters, transmission losses, dispersion, and instrument site responses. Though changing atmospheric ...