The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that Raung continued to erupt during 18-25 June. Seismicity during 16-18 June fluctuated but increased overall. A thermal anomaly on the crater floor was identified in a satellite image on 18 June. Ash plumes rose 500-1,100 m above the crater rim and drifted in multiple directions. Ash plumes during 19-20 June rose as high has 2 km above the crater rim and drifted SE, S, SW, and W. Incandescent emanated from the summit crater during 0302-0500 on 20 June; seismicity decreased that same day. Ash plumes rose 1-2 km above the crater rim and drifted S, SW, and W. PVMBG noted that eruptive activity during 5-20 June produced ash plumes that mostly deposited ash around the crater area. An ash plume on each day during 21-23 June rose 300-600 m above the crater rim and drifted N, NW, W, and SW. 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)