CVGHM reported that observations of Batu Tara from 30 March indicated that the E side of the volcano was most impacted by recent activity. Plant life on the E side was affected by hot ashfall and incandescent rockslides and cooled lava flows were observed at the E foot of the volcano. Steam and occasional ash plumes rose from the area where hot material interacted with the sea. White plumes rose from the summit to an altitude of approximately 1.7 km (5,600 ft) a.s.l. and drifted E. Based on satellite imagery and information from CVGHM, the Darwin VAAC reported that diffuse plumes rose to altitudes of 1.5 km (5,000 ft) a.s.l. and drifted W and NW during 4-10 April. On 5 April, plumes rose to 3 km (10,000 ft) a.s.l.

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.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)