Rumble III

Geography & Climate

Rumble III is located in New Zealand, within the Southern Kermadec Volcanic Arc of the broader Tonga-Kermadec Volcanic Regions. Situated at 35.74° S, 178.48° E in the Southern Hemisphere, the volcano lies within a temperate climate zone. With an elevation of -220 meters — below sea level — Rumble III is a submarine or submerged volcanic feature. Submarine volcanoes make up the majority of Earth's volcanic activity, though most eruptions go unobserved beneath the ocean surface. 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

Rumble III 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 New Zealand near Rumble III, 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

Rumble III has 6 recorded eruptions in the geological database, spanning from 1958 CE to 2008 CE. This eruption frequency indicates a moderately active volcanic system with periodic reawakenings. With eruptive activity as recently as 2008 CE, Rumble III remains an actively monitored volcano.

Significance

With 6 recorded eruptions on file, Rumble III has enough documented activity to help scientists identify patterns in its eruptive behavior. Given its recent activity, Rumble III is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

Rumble III seamount, the largest of the Rumbles group of submarine volcanoes along the South Kermadec Ridge, rises 2,300 m from the seafloor to within about 200 m of the surface. Collapse of the edifice produced a scarp open to the west and a large debris-avalanche deposit. Fresh-looking andesitic rocks have been dredged from the summit and basaltic lava from its flanks. It has been the source of several submarine eruptions detected by hydrophone signals.

— Smithsonian Institution, Global Volcanism Program