About Guguan
Guguan is a stratovolcano rising to 232 meters (761 feet) in United States's Northwestern Pacific Volcanic Regions. Its last known eruption was in 1883 CE. The volcano has produced 1 recorded eruption, with a maximum Volcanic Explosivity Index (VEI) of 2.
Geography & Climate
Guguan is located in United States, within the Mariana Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 17.31° N, 145.84° E in the Northern Hemisphere, the volcano lies within a tropical climate zone. At just 232 meters above sea level, Guguan is a relatively low-elevation volcanic feature. Despite its modest height, it remains an active geological formation with the same underlying magmatic processes as its taller counterparts. 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
Guguan 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 United States near Guguan, 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
Guguan has 1 recorded eruption in the geological database, spanning from 1883 CE to 1883 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1883 CE, reaching VEI 2 on the Volcanic Explosivity Index.
GVP Reference Summary
The island of Guguan, ~2.8 km in diameter, is composed of an eroded volcano on the south, a caldera with a post-caldera cone, and a northern volcano. The latter has three coalescing cones and a breached summit crater that fed lava flows to the W and NW. The only known reported eruption, between 1882 and 1884, produced the northern volcano and lava flows that reached the coast. Freycinet (Uranie 1817 Expedition) confused Guguan and Alamagan; reported eruptions in 1819 and 1901 (Kuno, 1962 CAVW) actually refer to solfataric activity on Alamagan (Corwin, 1971).
— Smithsonian Institution, Global Volcanism Program
1 Recorded Eruption
| Year | VEI | Type | Area |
|---|---|---|---|
| 1883 | 2 | Confirmed Eruption | — |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Guguan
Is Guguan an active volcano?+
Guguan is classified as active based on credible evidence of past eruptions. Although its last known eruption was in 1883 CE, volcanologists consider it capable of erupting again.
When did Guguan last erupt?+
The most recent recorded eruption of Guguan occurred in 1883 CE with a Volcanic Explosivity Index (VEI) of 2. The eruption was classified as a "Confirmed Eruption." Guguan has 1 recorded eruption in total.
How high is Guguan?+
Guguan has a summit elevation of 232 meters (761 feet) above sea level. At 232 meters, it is a relatively low-elevation volcano.
What type of volcano is Guguan?+
Guguan 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 Guguan located?+
Guguan is located in United States, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Mariana Volcanic Arc. Its exact coordinates are 17.314° latitude, 145.840° longitude.
Is it safe to visit Guguan?+
Guguan can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. United States may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
