Image from keizo/weblog
Hunga Tonga-Hunga Ha'apai (how's that for a name?), a shallow seamount in Tonga, appears to have erupted. An air passenger snapped some pictures of an eruption occurring in the ocean between the Tongatapu and Vava'u and pilots in the area report that (unsurprisingly), the feature is new.
Hunga Tonga-Hunga Ha'apai - at least the part above water (look in the bottom of the image, the islands are marked in green) - is made of two small islands that cap the main seamount and ring the volcano's caldera. The last known eruption from the volcano was in 1988 - over twenty years ago - so this is exciting to see a new event. However, the 1988 eruption was apparently quite small (VEI 0), so the last major eruption might have been as far back as 1937 (VEI 2). Beyond that, not much is know about this volcano in the Tongan arc.