This project will investigate the seismic structure of oceanic mantle lithosphere using an active-source seismic refraction experiment along an 800-km-long transect in the Western Atlantic Ocean. The transect extends along a plate kinematic flow line that lies entirely within a single spreading-center segment, on lithosphere ranging from 87 to 145 million years old. The experiment will determine if the lithospheric mantle in the Atlantic is stratified, the magnitude and form of anisotropy over length scales of a few hundred kilometers, the constraints the character of oceanic Pn coda places on the nature of small-scale lateral heterogeneity, and the parameters that maximize the range at which mantle phases can be recorded using airgun source and ocean-bottom receivers.
