The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that ash was present in emissions at Raung during 5-7 June. Emissions became continuous around 0600 on 5 June. The ash-bearing white to medium-gray plumes rose 600 m above the summit and drifted NE. Seismic energy did not increase and deformation data showed subsidence, suggesting that the source of the emissions was relatively shallow. Gray gas-and-ash plumes were continuous on 7 June, and possibly continuous at least through 2329 on 8 June, rising to 400 m above the crater rim. Ashfall was reported in the Linggusar and Sumberwringin area, Bondowoso Regency, about 17 km NNW. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.

Geological Summary. Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The unvegetated summit is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively.

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