Report on Gamkonora (Indonesia) — 11 July-17 July 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
11 July-17 July 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Gamkonora (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 11 July-17 July 2007. Smithsonian Institution and US Geological Survey.
1.38°N, 127.53°E; summit elev. 1635 m
All times are local (unless otherwise noted)
CVGHM reported that on 10 July, incandescent material from Gamkonora was propelled about 5 m above the summit and intermittently showered the flank. On 11 July, ash plumes rose to altitudes of 5.9-9.4 km (19,400-30,800 ft) a.s.l. During 12-15 July, visual observations of ash plumes were hindered by cloud cover. On 16 July, the Alert Level was lowered from 4 to 3 (on a scale of 1-4) due to a drastic decrease in seismic activity, a decline in ash plume altitudes, and the absence of incandescence observed at the summit during 11-15 July.
Geological Summary. The shifting of eruption centers on Gamkonora, the highest peak of Halmahera, has produced an elongated series of summit craters along a N-S trending rift. Youthful-looking lava flows originate near the cones of Gunung Alon and Popolojo, south of Gamkonora. Since its first recorded eruption in the 16th century, typical activity has been small-to-moderate explosive eruptions. Its largest historical eruption, in 1673, was accompanied by tsunamis that inundated villages.