PVMBG issued VONAs noting recent increased gas emissions at Batu Tara but no confirmed eruptions. Ground-based observers reported that at 1453 and 1617 on 28 April gas emissions rose 1-1.2 km above the summit and drifted W. At 0054 on 2 May gas emissions rose 500 m and drifted W. The Alert Level remained at 1 (on a scale of 1-4).

Geological Summary. The small isolated island of Batu Tara in the Flores Sea about 50 km N of Lembata (fomerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks to within 50 m of the summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption, during 1847-52, produced explosions and a lava flow.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)