About Suiyo Seamount
Suiyo Seamount is a stratovolcano rising to -991 meters (-3,251 feet) in Japan's Northwestern Pacific Volcanic Regions. No historical eruptions have been recorded, though the volcano is classified based on geological evidence of past activity.
Geography & Climate
Suiyo Seamount is located in Japan, within the Ogasawara Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 28.57° N, 140.63° E in the Northern Hemisphere, the volcano lies within a subtropical climate zone. With an elevation of -991 meters — below sea level — Suiyo Seamount 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
Suiyo Seamount 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 Japan near Suiyo Seamount, 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.
GVP Reference Summary
Suiyo, one of the Shichiyo Seamounts, named for the seven days of the week, lies south of Sofugan volcano. Suiyo ("Wednesday") is a basaltic-to-dacitic submarine volcano and lava dome that rises about 1,400 m from the sea floor to within about 1,000 m of the surface. The summit crater is 1.5 km wide and about 500 m deep. Major hydrothermal activity was observed in July 1991, with temperatures reaching more the 290°C, and the volcano was reclassified as active by the Japan Meteorological Agency.
— Smithsonian Institution, Global Volcanism Program
0 Recorded Eruptions
No eruption records available for Suiyo Seamount.
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Suiyo Seamount
Is Suiyo Seamount an active volcano?+
Suiyo Seamount is not currently classified as active. Its activity evidence is listed as "Unrest / Holocene." No recorded eruptions have been documented. However, no volcano is ever considered permanently extinct.
How high is Suiyo Seamount?+
Suiyo Seamount has a summit elevation of -991 meters (-3,251 feet) above sea level. With an elevation of -991 meters (below sea level), this is a submarine or submerged volcanic feature.
What type of volcano is Suiyo Seamount?+
Suiyo Seamount 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 Suiyo Seamount located?+
Suiyo Seamount is located in Japan, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Ogasawara Volcanic Arc. Its exact coordinates are 28.575° latitude, 140.633° longitude.
Is it safe to visit Suiyo Seamount?+
Suiyo Seamount can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Japan may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
