About Upolu
Upolu is a shield rising to 1,100 meters (3,609 feet) in Samoa's Southern Pacific Volcanic Regions. No historical eruptions have been recorded, though the volcano is classified based on geological evidence of past activity.
Geography & Climate
Upolu is located in Samoa, within the Samoan Hotspot Volcano Group of the broader Southern Pacific Volcanic Regions. Situated at 13.94° S, 171.72° W in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 1,100 meters above sea level, Upolu is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a shield, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Upolu 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 Samoa near Upolu, 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 basalt / picro-basalt, 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.
GVP Reference Summary
The massive, basaltic shield volcano forming 75-km-long Upolu Island in Samoa is elongated in an E-W direction and was constructed during two periods of extensive eruptions during the Pliocene and Pleistocene. The most extensive activity during the Pleistocene took place along a 20-km segment along the central axis of the island. Following a lengthy period of erosion, the latest lava flows, at least three of which were estimated to be as young as a few hundred to a few thousand years old, were erupted from vents near the crest of the island at its center and western side (Stearns, 1944). One of the youngest flows reached the north-central coast along a roughly 1.5-km-wide front east of Vailele Bay, and another traveled down the Lefaga River channel and reached the SW coast at Lefaga Bay. Apolima Island off the western tip of Upolu is a Holocene tuff cone too young to be fringed by a coral reef, and other reef-free areas along the coastline may be formed by Holocene lava flows.
— Smithsonian Institution, Global Volcanism Program
0 Recorded Eruptions
No eruption records available for Upolu.
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Upolu
Is Upolu an active volcano?+
Upolu is classified as active based on credible evidence of past eruptions. Although its last known eruption was in prehistoric times, volcanologists consider it capable of erupting again.
How high is Upolu?+
Upolu has a summit elevation of 1,100 meters (3,609 feet) above sea level. At 1,100 meters, it is a moderately sized volcanic peak, roughly comparable to Mount Vesuvius (1,281m).
What type of volcano is Upolu?+
Upolu is classified as a Shield. Shield volcanoes have distinct geological characteristics that set them apart from other volcanic types.
Where is Upolu located?+
Upolu is located in Samoa, in the Southern Pacific Volcanic Regions. More specifically, it lies within the Samoan Hotspot Volcano Group. Its exact coordinates are -13.935° latitude, -171.720° longitude.
Is it safe to visit Upolu?+
Upolu can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Samoa may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
