Global Volcanism Program | Image GVP-11433
The three small islands of Nguna, Pele, and Emau at the upper left, are located N of the large island of Efete (also known as Vate). Nguna and Pele appear to be a single island in this NASA Space Shuttle image (N is to the upper left), and Emau is the small circular island at the at the top center. These islands are thought to lie along or near the southern rim of a largely-submarine caldera of uncertain dimensions that extends to the N and may have formed about 2,000 years ago.
NASA Space Shuttle image STS068-206-50, 1994 (http://eol.jsc.nasa.gov/).
This image is made available as a Public Domain Work, but proper attribution is appreciated.