About Unnamed
Unnamed is a stratovolcano rising to -296 meters (-971 feet) in Tonga's Tonga-Kermadec Volcanic Regions. It has been active in recent decades, with its last eruption in 2017 CE. The volcano has produced 5 recorded eruptions, with a maximum Volcanic Explosivity Index (VEI) of 1.
Geography & Climate
Unnamed is located in Tonga, within the Tofua Volcanic Arc of the broader Tonga-Kermadec Volcanic Regions. Situated at 20.85° S, 175.55° W in the Southern Hemisphere, the volcano lies within a tropical climate zone. With an elevation of -296 meters — below sea level — Unnamed 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
Unnamed 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 Tonga near Unnamed, 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 no data (checked), which influences the viscosity of the magma and, consequently, the style of eruptions this volcano produces. Rock chemistry is one of the most important factors in determining whether a volcano erupts explosively or effusively.
Eruption History Summary
Unnamed has 5 recorded eruptions in the geological database, spanning from 1911 CE to 2017 CE. The most powerful recorded event was a gentle, effusive event in 1999 CE, reaching VEI 1 on the Volcanic Explosivity Index. This eruption frequency indicates a moderately active volcanic system with periodic reawakenings. With eruptive activity as recently as 2017 CE, Unnamed remains an actively monitored volcano.
Significance
With 5 recorded eruptions on file, Unnamed has enough documented activity to help scientists identify patterns in its eruptive behavior. Given its recent activity, Unnamed is closely monitored by geological survey organizations to provide early warning of future unrest.
GVP Reference Summary
An unnamed submarine volcano is located along the Tofus volcanic arc 35 km NW of the Niu Aunofo lighthouse on Tongatapu Island. The first documented eruptions took place in 1911 and 1923; an ephemeral island was formed in 1999. A submarine eruption in January 2017 produced discolored water visible in satellite imagery.
— Smithsonian Institution, Global Volcanism Program
5 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 2017 | 0 | Confirmed Eruption | Submarine |
| 1999 | 1 | Confirmed Eruption | — |
| 1970 | 0 | Uncertain Eruption | — |
| 1923 | 0 | Confirmed Eruption | — |
| 1911 | 0 | Confirmed Eruption | — |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Unnamed
Is Unnamed an active volcano?+
Yes, Unnamed is considered an active volcano. Its most recent eruption was in 2017 CE. The volcano is monitored by geological agencies, and its activity status is based on observed eruptions within recorded history.
When did Unnamed last erupt?+
The most recent recorded eruption of Unnamed occurred in 2017 CE with a Volcanic Explosivity Index (VEI) of 0. The eruption was classified as a "Confirmed Eruption." Unnamed has 5 recorded eruptions in total.
How high is Unnamed?+
Unnamed has a summit elevation of -296 meters (-971 feet) above sea level. With an elevation of -296 meters (below sea level), this is a submarine or submerged volcanic feature.
What type of volcano is Unnamed?+
Unnamed is classified as a Stratovolcano. Stratovolcanoes (also called composite volcanoes) are steep, conical volcanoes built up by many layers of hardened lava, tephra, and volcanic ash. They are among the most common and dangerous types, known for explosive eruptions.
Where is Unnamed located?+
Unnamed is located in Tonga, in the Tonga-Kermadec Volcanic Regions. More specifically, it lies within the Tofua Volcanic Arc. Its exact coordinates are -20.852° latitude, -175.550° longitude.
Is it safe to visit Unnamed?+
Visiting Unnamed requires checking current volcanic activity and alert levels. As an active volcano with eruptions as recent as 2017 CE, conditions can change rapidly. Always consult local geological authorities and follow official warnings before visiting. Many active volcanoes have designated safe viewing areas and guided tour options.
