Raung (front) and Ijen (back) volcanoes. The crew of Quatas flight 41 (Sydney-Jakarta) observed a very dense black plume emerging intermittently from a flank vent on 10 September at 1508 (local time). The plume was drifting N at about 6 km altitude, well below the aircraft's altitude of nearly 12 km. This slide (taken two days later from a commercial flight) shows a voluminous, dense, mostly white plume with small pulses of ash in its center. Photo by Jeff Post, 1991 (Smithsonian Institution).

A boatload of visitors prepares to sail to Anak Krakatau Island, seen behind the mast of the boat. Anak Krakatau was constructed within the 1883 caldera, whose southern rim forms the conical Rakata peak in the right background. Photo by Dick Fiske, 1983 (Smithsonian Institution).

Steam rises from a sulfur-encrusted fumarole at Kawah Mas ("Golden Crater"), a frequently visited destination at Papandayan volcano. A large number of high-temperature fumaroles, with temperatures of several hundred degrees Centigrade, are located within Kawah Mas. Photo by Lee Siebert, 1995 (Smithsonian Institution).

Farmers cultivate land on the eastern flank of picturesque Gunung Sundoro, one of the most symmetrical volcanoes in Java. The 3136-m-high stratovolcano towers 2500 m above its base, immediately NW of its neighboring conical volcano, Gunung Sumbing. Photo by Lee Siebert, 1995 (Smithsonian Institution).