The island of Vanua Lava, with a surface area of 334 km², corresponds to the emerged part of a vast building about 35 km wide and 2500 m high from the ocean floor. It is one of the largest Banks Islands in Vanuatu.
Unlike other large volcanoes in Vanuatu, predominantly basaltic to andesitic, the Suretamatai has no caldera at the top.
A chain of small stratovolcans, oriented along an NNE-SSW line, gives the volcano a slight slope and an irregular profile.
The youngest cone near the northern end of the chain is the highest and contains a lake 900 meters wide and 100 m deep in its crater at the top.
The island is dominated by the active cone, the Suretamatai (921 m). The latter was active in 1841, 1856 and 1865.
In 1965, an ash plume was emitted by a new crater on the NW flank, while in 1966 small explosions (probably related to water-magma interactions) occurred. Recent activity is reduced to that of solfatare.
At present, the main geothermal zone along the Sulfur River on the eastern flank of the active cone contains fumaroles, hot springs and boiling ponds.
(Ph. Bani et al., (2012) A. Beaumais et al. (2013).)