Abstract: The oceans are mysterious, dangerous and largely unexplored, yet they are central to the habitability of life on Earth. Many natural phenomena that occur throughout the world's oceans and seafloor also occur in, on, and above the Juan de Fuca tectonic plate, which sits just off our coast. Scientists with the National Science Foundation's Ocean Observatories Initiative will use a planned underwater research observatory associated with the plate to investigate such global processes as major ocean currents, active earthquake zones, creation of new seafloor, and rich environments of marine plants and animals in an effort to explore and better understand this last frontier on Earth.