Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 22 May-28 May 2013
Managing Editor: Sally Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Gamkonora (Indonesia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 22 May-28 May 2013. Smithsonian Institution and US Geological Survey. https://volcano.si.edu/showreport.cfm?gvpvar=GVP.WVAR20130522-268040
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.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
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 recorded eruption, in 1673, was accompanied by tsunamis that inundated villages.