Spotlight 8: Vailulu’u Seamount

• Main Authors: Anthony A.P. Koppers, Hubert Staudigel, Stanley R. Hart, Craig Young, Jasper G. Konter
• Format: Article
• Language: English
• Published: The Oceanography Society 2010-03-01
• Series: Oceanography
• Subjects: Vailulu’u; seamounts; Nafanua
• Online Access: http://tos.org/oceanography/issues/issue_archive/issue_pdfs/23_1/23-1_koppers2.pdf

Vailulu’u seamount is an active underwater volcano that marks the end of the Samoan hotspot trail. Vailulu’u has a simple conical morphology with a largely enclosed volcanic crater at relatively shallow water depths, ranging from 590 m (highest point on the crater rim) to 1050 m (crater floor). The crater hosts a 300-m-high central volcanic cone, Nafanua, that was formed between 2001 and 2004. Seismic activity at Vailulu’u included a series of globally recorded magnitude 4.1–4.9 earthquakes in 1973 and 1995, and substantial volcano-tectonic activity recorded over 45 days in 2000, with an average of four earthquakes per day and a maximum of 40 per day. Hypocenter locations are directly located below the major hydrothermal vent areas.