Kie Besi

Geography & Climate

Kie Besi is located in Indonesia, within the Halmahera Volcanic Arc of the broader Western Pacific Volcanic Regions. Situated at 0.32° N, 127.40° E in the Northern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 1,357 meters above sea level, Kie Besi is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Kie Besi sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Indonesia near Kie Besi, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Kie Besi has 11 recorded eruptions in the geological database, spanning from 1550 CE to 1988 CE. The most powerful recorded event was a cataclysmic eruption with ash columns reaching the stratosphere in 1861 CE, reaching VEI 4 on the Volcanic Explosivity Index. Notable eruptions include 1988 CE (VEI 3), 1861 CE (VEI 4), 1760 CE (VEI 4). This level of eruptive frequency indicates a persistently active volcanic system that warrants ongoing monitoring. The most recent eruption in 1988 CE places this volcano within the modern era of volcanological observation.

Significance

With a maximum recorded VEI of 4, Kie Besi has demonstrated the capacity for significant explosive eruptions that can impact regional aviation, agriculture, and communities tens of kilometers from the summit. VEI 4 eruptions produce ash columns reaching 15-25 kilometers into the atmosphere. With 11 recorded eruptions, Kie Besi has a substantial eruptive history that provides valuable data for understanding volcanic behavior and assessing future hazards in the Western Pacific Volcanic Regions region. Given its recent activity, Kie Besi is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

Kie Besi volcano, forming the 10-km-wide Makian island off the west coast of Halmahera, has been the source of infrequent, but strong eruptions that have devastated villages on the island. The large 1.5-km-wide summit crater, containing a small lake on the NE side, gives the peak a flat-topped profile. Two prominent valleys extend to the coast from the summit crater on the north and east sides. Four cones are found on the western flanks. Eruption have been recorded since about 1550; major eruptions in 1646, 1760-61, 1861-62, 1890, and 1988 caused extensive damage and many fatalities.

— Smithsonian Institution, Global Volcanism Program