Axial Seamount Volcano - John Seach


Juan de Fuca Ridge, East Pacific Ocean

45.95 N, 130.00 W
summit elevation -1500 m
submarine volcano

Axial volcano is located near the intersection of the Juan de
Fuca ridge and the Cobb-Eickelberg seamount chain, 480 km west of Cannon Beach, Oregon, USA.

The summit contains a 3 x 8 km wide caldera, breached on SE. Hydrothermal vents colonized with biological communities are located near the caldera. The summit caldera is relatively smooth compared to the volcano flanks. The rectangular shaped summit caldera is the main feature of the summit plateau. The caldera is larger than calderas in Hawaii, but smaller than those in Iceland. There is extensive fissuring associated with the north rift zone. A group of fissures are located in 100-200 m area across the crest of a ridge that extends for 5 km.

D.D. Cone, is located about 3 km northwest of the caldera. It is about 2 km in diameter and 100 m in relief and has a small breached crater facing ENE.

Volcanic activity is associated with the Cobb hotspot. The volcano rises 700 metres above the ridge, has rift zones extending 50 kilometres north and south.

Hydrothermal Vents
Most hydrothermal vents are located on the south caldera, and are associated with the south rift zone. The Axial Caldera chimneys are young in appearance and lack associated sulfide mound deposits such as those described from some other ridge-crest sites.

1998 Eruption
An eruption was detected seismically in January 1998 when lava erupted from a 9 km long fissure. The caldera subsided by 3 m during the eruption.

1983 Hydrothermal Venting
Hydrothermal venting was discovered at the volcano in 1983.

Axial Seamount Volcano Eruptions