According to the Darwin VAAC eruptive activity at Barren Island produced ash plumes during 28 March-1 April. Ash plumes identified in satellite images at 1320 and 1930 on 28 March rose to 2.4 km (8,000 ft) a.s.l. and drifted NW. A strong thermal anomaly over the summit was visible in the 1930 image. Ash dissipated within about four hours. A larger thermal anomaly was visible in a satellite image at 0410 on 31 March. Ash plumes visible in images at 0410 and 1010 on 31 March rose to 2.4 km a.s.l. and drifted W. By 1440 ash was not visible, though weather conditions prevented views. At 1010 on 1 April a continuous ash plume rose to 1.8 km (6,000 ft) a.s.l. and drifted S.

Geological Summary. Barren Island, a possession of India in the Andaman Sea about 135 km NE of Port Blair in the Andaman Islands, is the only historically active volcano along the N-S volcanic arc extending between Sumatra and Burma (Myanmar). It is the emergent summit of a volcano that rises from a depth of about 2250 m. The small, uninhabited 3-km-wide island contains a roughly 2-km-wide caldera with walls 250-350 m high. The caldera, which is open to the sea on the west, was created during a major explosive eruption in the late Pleistocene that produced pyroclastic-flow and -surge deposits. Historical eruptions have changed the morphology of the pyroclastic cone in the center of the caldera, and lava flows that fill much of the caldera floor have reached the sea along the western coast.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)