Ofu-Olosega

sopka – Shield(s), United States, Southern Pacific Volcanic Regions

Kde

United States, Southern Pacific Volcanic Regions

Typ (GVP)

Shield(s)

Nadmořská výška

639 m

Tektonické prostředí

Subduction zone / Oceanic crust (< 15 km)

Poslední známá erupce

1866

Poloha

-14,175°, -169,618°

The two triangle-shaped islands of Ofu and Olosega in eastern Samoa, with a combined length of 6 km, are separated by a narrow strait. The islands are formed by two eroded, coalescing basaltic shield volcanoes whose slopes dip to the east and west. Steep cliffs up to 600-m high truncate the northern and southern sides of the islands. The narrow, steep-sided ridge forming the eastern tip of Ofu Island consists of a dike complex. The shield volcano on Ofu is cut on the north by the A'ofa caldera; bathymetry suggests that a caldera may also exist on the Sili shield volcano of Olosega. The Nu'utele tuff cone, forming a small crescent-shaped island immediately off the west end of Ofu Island, is Holocene in age. A submarine eruption took place in 1866 at the opposite end of the two islands, 3 km SE of Olosega, along the ridge connecting Olosega with Ta'u Island.

Text: Smithsonian Global Volcanism Program.

Údaje o sopce: Smithsonian Global Volcanism Program. Další sopky a průduchy.