The East Blanco Depression (EBD) is a pull-apart basin within the western Blanco Transform Fault Zone, a right-lateral transform fault that links the Juan de Fuca Ridge and Gorda Ridge (Dziak et al., 1996). In January 1994 a T-wave swarm suggested eruptive activity. Investigations later that year were inconclusive regarding an associated eruption, but found an active hydrothermal mound on the flanks of a pillow-lava volcano. Dziak et al. (1996) considered the EBD to have been the site of recent seafloor eruptions.