Axial Seamount

A submarine volcano in seven thousand feet of water, 300 miles off the coast of Oregon, may have grown to an underwater elevation of 2,000 feet off the ocean floor. Named by scientists “Axial Seamount”, the underwater volcano is thought to have also erupted in 1998 and 2011.

The Juan de Fuca plate and ridge are important bits of geology between Portland and the eruption. These features are further out to sea than the infamous Cascadia Subduction Zone. 20 miles off the coast of Oregon, the 1700 Cascadia earthquake caused tsunamis in Japan, lowered Cascade forest into tidal swamps, and may have caused waves 60 feet high.

Between the Cascadia fault and Axial Seamount lies the Juan de Fuca plate, one of the Earth’s smallest plate remnants. At some point in our geologic future, the subduction of the Juan de Fuca plate under the Cascadia Subduction Zone will violently tilt the remainder of the plate upwards, which could cause a Tsunami of epic proportions.

http://www.seattletimes.com/seattle-news/science/did-she-blow-nw-submarine-volcano-likely-just-erupted/