A plume from the summit area of Welirang . . . was photographed by Space Shuttle astronauts on 13 September at [1535] (photo no. S48-151-064) (figure 1). The dense portion of the apparently ash-poor plume extended roughly 50 km N and more diffuse material continued for another 65 km. The summit area was white and apparently de-vegetated. A plume was observed again on direct video downlink from the spacecraft on [17] September at [1306]. No ground reports were available at press time.

Geologic Background. The twin volcanoes of Arjuno and Welirang anchor the SE and NW ends, respectively, of a 6-km-long line of volcanic cones and craters. The Arjuno-Welirang complex overlies two older volcanoes, Gunung Ringgit to the east and Gunung Linting to the south. The summit areas of both volcanoes are unvegetated. Additional pyroclastic cones are located on the north flank of Gunung Welirang and along an E-W line cutting across the southern side of Gunung Arjuno that extends to the lower SE flank. Fumarolic areas with sulfur deposition occur at several locations on Gunung Welirang.

Information Contacts: C. Evans and D. Helms, NASA-SSEOP.