Krummel-Garbuna-Welcker

Geography & Climate

Krummel-Garbuna-Welcker is located in Papua New Guinea, within the Bismarck Volcanic Arc of the broader Southwestern Pacific Volcanic Regions. Situated at 5.42° S, 150.03° E in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 564 meters above sea level, Krummel-Garbuna-Welcker 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

Krummel-Garbuna-Welcker 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 Papua New Guinea near Krummel-Garbuna-Welcker, 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

Krummel-Garbuna-Welcker has 4 recorded eruptions in the geological database, spanning from 150 CE to 2008 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 2008 CE, reaching VEI 2 on the Volcanic Explosivity Index. These eruptions span roughly 1,858 years of volcanic history. With eruptive activity as recently as 2008 CE, Krummel-Garbuna-Welcker remains an actively monitored volcano.

GVP Reference Summary

The basaltic-to-dacitic Krummel-Garbuna-Welcker Volcanic Complex consists of three volcanic peaks located along a 7-km N-S line above a shield-like foundation at the southern end of the Willaumez Peninsula. The central and lower peaks of the centrally located Garbuna contain a large vegetation-free area that is probably the most extensive thermal field in Papua New Guinea. A prominent lava dome and blocky lava flow in the center of thermal area have resisted destruction by thermal activity, and may be of Holocene age. Krummel volcano at the south end of the group contains a summit crater, breached to the NW. The highest peak of the group is Welcker volcano, which has fed blocky lava flows that extend to the eastern coast of the peninsula. The last major eruption from both it and Garbuna volcanoes took place about 1800 years ago. The first historical eruption took place at Garbuna in October 2005.

— Smithsonian Institution, Global Volcanism Program