Suretamatai

Geography & Climate

Suretamatai is located in Vanuatu, within the Vanuatu Volcanic Arc of the broader Southwestern Pacific Volcanic Regions. Situated at 13.80° S, 167.47° E in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 921 meters above sea level, Suretamatai is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Suretamatai sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Vanuatu near Suretamatai, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Suretamatai has 4 recorded eruptions in the geological database, spanning from 1841 CE to 1965 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1965 CE, reaching VEI 2 on the Volcanic Explosivity Index. These eruptions span roughly 124 years of volcanic history. The most recent eruption in 1965 CE places this volcano within the modern era of volcanological observation.

GVP Reference Summary

Suretamatai volcano (also known as Soritimeat) forms much of Vanua Lava Island, one of the largest of Vanuatu's Banks Islands. The younger lavas overlie a number of small older stratovolcanoes that form the island. In contrast to other large volcanoes of Vanuatu, the dominantly basaltic-to-andesitic Suretamatai does not contain a youthful summit caldera. A chain of small stratovolcanoes oriented along a NNE-SSW line gives the low-angle volcano an irregular profile. The youngest cone, near the northern end of the chain, is the largest and contains a lake of variable depth within its 900-m-wide, 100-m-deep summit crater. Activity reported during the 19th century consisted of moderate explosive eruptions.

— Smithsonian Institution, Global Volcanism Program