Tinakula

Geography & Climate

Tinakula is located in Solomon Islands, within the Vanuatu Volcanic Arc of the broader Southwestern Pacific Volcanic Regions. Situated at 10.39° S, 165.80° E in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 796 meters above sea level, Tinakula 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

Tinakula 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 Solomon Islands near Tinakula, 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

Tinakula has 20 recorded eruptions in the geological database, spanning from 1869 CE to 2018 CE. The most powerful recorded event was a severe eruption capable of regional ash fall and pyroclastic flows in 2017 CE, reaching VEI 3 on the Volcanic Explosivity Index. Notable eruptions include 2017 CE (VEI 3), 1965 CE (VEI 3), 1951 CE (VEI 3). With an average interval of roughly 7 years between eruptions over a span of 149 years, this is one of the more frequently active volcanoes in the database. This persistent activity suggests a robust and well-supplied magma system beneath the volcano. With eruptive activity as recently as 2018 CE, Tinakula remains an actively monitored volcano.

Significance

With a maximum recorded VEI of 3, Tinakula has produced eruptions capable of generating pyroclastic flows and significant ash fall in the surrounding area. While not among the largest eruptions globally, VEI 3 events pose serious hazards to local populations and can disrupt regional air travel. Its 20 recorded eruptions make it one of the most prolific volcanoes in our database, reflecting a persistent and well-documented eruptive history that has provided volcanologists with extensive data for understanding eruption patterns and forecasting future activity. Given its recent activity, Tinakula is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

The small 3.5-km-wide island of Tinakula is the exposed summit of a massive stratovolcano at the NW end of the Santa Cruz islands. It has a breached summit crater that extends from the summit to below sea level. Landslides enlarged this scarp in 1965, creating an embayment on the NW coast. The Mendana cone is located on the SE side. The dominantly andesitic volcano has frequently been observed in eruption since the era of Spanish exploration began in 1595. In about 1840, an explosive eruption apparently produced pyroclastic flows that swept all sides of the island, killing its inhabitants. Recorded eruptions have frequently originated from a cone constructed within the large breached crater. These have left the upper flanks and the steep apron of lava flows and volcaniclastic debris within the breach unvegetated.

— Smithsonian Institution, Global Volcanism Program