About Megata
Megata is a maar(s) rising to 160 meters (525 feet) in Japan's Northwestern Pacific Volcanic Regions. The volcano is currently active, with its most recent eruption in 2050 BCE. The volcano has produced 2 recorded eruptions.
Geography & Climate
Megata is located in Japan, within the Northeast Japan Volcanic Arc of the broader Northwestern Pacific Volcanic Regions. Situated at 39.95° N, 139.72° E in the Northern Hemisphere, the volcano lies within a temperate climate zone. At just 160 meters above sea level, Megata 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 minor (basaltic), which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Megata 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 Megata, 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
Megata has 2 recorded eruptions in the geological database, spanning from 7050 BCE to 2050 BCE. These eruptions span roughly 5,000 years of volcanic history.
GVP Reference Summary
Megata, a group of three small maars along the tip of the Oga Peninsula in NW Honshu, has been active during the Holocene (Ishikawa et al., 1957). Lakes 300-600 m wide fill the basaltic-to-dacitic maars, which are a noted locality for mantle-derived xenoliths. Ichinomegata, the easternmost, largest, and oldest of the three maars, is 600 m in diameter. Ninomegata and Sannomegata are located immediately E and S of Toga Bay, which itself is a maar. The rim of the rhyolitic Toga (Togowan) maar, larger than the Megata maars, is breached by the sea on the western side and was formed about 450,000 years ago. The Megata maars are mostly late Pleistocene in age, but Murayama (1987) noted that pottery from roughly 4,000 years before present (Jomon Period) has been found within tephra layers from the maars.
— Smithsonian Institution, Global Volcanism Program
2 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 2050 BCE | — | Confirmed Eruption | — |
| 7050 BCE | — | Confirmed Eruption | — |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Megata
Is Megata an active volcano?+
Megata is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 2050 BCE. However, no volcano is ever considered permanently extinct.
When did Megata last erupt?+
The most recent recorded eruption of Megata occurred in 2050 BCE. The eruption was classified as a "Confirmed Eruption." Megata has 2 recorded eruptions in total.
How high is Megata?+
Megata has a summit elevation of 160 meters (525 feet) above sea level. At 160 meters, it is a relatively low-elevation volcano.
What type of volcano is Megata?+
Megata is classified as a Maar(s). Maar(s) volcanoes have distinct geological characteristics that set them apart from other volcanic types.
Where is Megata located?+
Megata is located in Japan, in the Northwestern Pacific Volcanic Regions. More specifically, it lies within the Northeast Japan Volcanic Arc. Its exact coordinates are 39.950° latitude, 139.725° longitude.
Is it safe to visit Megata?+
Megata 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.
