Report on Gamkonora (Indonesia) — 22 May-28 May 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 May-28 May 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Gamkonora (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 May-28 May 2013. 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 a phreatic eruption at Gamkonora on 23 January was preceded by increased seismicity. Some types of seismic signals increased during March-April while others decreased. On 24 May seismicity indicative of shallow magma movement increased and diffuse white plumes rose 100-300 above the crater. During 25-27 May dense white-to-gray plumes rose 200-500 m above the crater. On 27 May the Alert Level was raised to 3 (on a scale of 1-4). Residents and tourists were asked not to venture near the crater within a radius of 3 km.
Geologic Background. 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.