BackgroundA group of small islands south of Tongoa Island were considered to be remnants of a once-larger landmass that foundered during the Holocene. Ewose, Buninga, and Tongariki islands, at the southern end of the Shepherd Islands, lie on the rim of a proposed caldera thought to be one of several formed in the central volcanic chain of Vanuatu about 2000 years ago (Crawford et al. 1988, Macfarlane et al. 1988). Eissen et al. (1991) did not find evidence for a caldera at this location. Pyroclastic rocks intruded by dikes are exposed on Ewose, whereas Buninga and Makura are largely composed of tilted lava flows. Tongariki consists of remnants of a basaltic stratovolcano with dacitic pumiceous tuffs in low-lying areas.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8