About Kita-Bayonnaise
Kita-Bayonnaise is a caldera rising to -360 meters (-1,181 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
Kita-Bayonnaise is located in Japan, within the Izu Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 32.10° N, 139.85° E in the Northern Hemisphere, the volcano lies within a subtropical climate zone. With an elevation of -360 meters — below sea level — Kita-Bayonnaise 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 caldera, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Kita-Bayonnaise 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 Kita-Bayonnaise, 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 rhyolite, a silica-rich volcanic rock associated with highly viscous magma. Rhyolitic eruptions can be extremely explosive and are responsible for some of the largest volcanic events in Earth's history, including supervolcanic caldera-forming eruptions. The high silica content traps dissolved gases, building enormous pressure that can lead to catastrophic explosive releases.
GVP Reference Summary
The large submarine Kita-Bayonnaise (North Bayonnaise) submarine caldera, also known as Myojin Knoll, lies between the Aogashima and Myojinsho (also called Beyonesu Rocks) calderas abotu 300 km SSE of the Izu Peninsula. The 6-7 km wide caldera has walls 500-900 m high that reveal rhyolitic lava flows, shallow intrusions, and volcaniclastic deposits. The high point on the western rim is a pumice-mantled remnant of the pre-collapse volcanic complex that reaches a depth of 360 m. A voluminous deposit of coarse rhyolitic pumice from the caldera-forming eruption covers the rim and outer flanks. Post-caldera eruptions formed a lava dome that rises 250 m above the caldera floor. The age of the caldera is not known, but was considered by Fiske et al. (2001) to perhaps be as young as a few thousand years. An active hydrothermal vent field lies on the eastern caldera floor and has produced a polymetallic sulfide deposit from vent chimneys up to 30 m high that emit fluids as hot as 278°C.
— Smithsonian Institution, Global Volcanism Program
0 Recorded Eruptions
No eruption records available for Kita-Bayonnaise.
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Kita-Bayonnaise
Is Kita-Bayonnaise an active volcano?+
Kita-Bayonnaise is not currently classified as active. Its activity evidence is listed as "Evidence Uncertain." No recorded eruptions have been documented. However, no volcano is ever considered permanently extinct.
How high is Kita-Bayonnaise?+
Kita-Bayonnaise has a summit elevation of -360 meters (-1,181 feet) above sea level. With an elevation of -360 meters (below sea level), this is a submarine or submerged volcanic feature.
What type of volcano is Kita-Bayonnaise?+
Kita-Bayonnaise is classified as a Caldera. Calderas are large volcanic depressions formed when a volcano erupts so powerfully that its magma chamber collapses, creating a basin that can be kilometers wide. They are often sites of some of Earth's largest eruptions.
Where is Kita-Bayonnaise located?+
Kita-Bayonnaise is located in Japan, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Izu Volcanic Arc. Its exact coordinates are 32.100° latitude, 139.850° longitude.
Is it safe to visit Kita-Bayonnaise?+
Kita-Bayonnaise 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.
