Overview of Chokaisan
Chokaisan is a stratovolcano located in Japan. It has an elevation of 2,236 meters and is situated in a subduction zone setting with continental crust greater than 25 kilometers thick. The volcano has a documented history of activity spanning approximately three millennia, with 14 confirmed eruptions recorded in the official source.
Eruption History by Century
Historical records indicate that volcanic activity at Chokaisan has occurred in various centuries, with the 9th century CE showing the highest frequency of events in the available data.
| Century | Number of Eruptions |
|---|---|
| 11th century BCE | 1 |
| 5th century BCE | 1 |
| 7th century BCE | 1 |
| 10th century CE | 1 |
| 8th century CE | 1 |
| 9th century CE | 3 |
| 17th century CE | 1 |
| 18th century CE | 2 |
| 19th century CE | 2 |
| 20th century CE | 1 |
Notable Eruptions
While the table above summarizes the frequency of eruptions by century, the following are specific examples of confirmed eruptions recorded by the source:
- 1050 BCE: An eruption occurred on the west flank, specifically at the Saruana crater. This event is classified as a VEI 0 eruption and was identified through tephrochronology.
- 711 CE: A confirmed eruption is recorded, though the exact year is uncertain by a margin of three years.
- 871 CE: An eruption began on May 5 and is recorded as a VEI 2 event.
- 1834 CE: A significant eruption occurred from July 9 to July 16, classified as a VEI 2 event.
- 1974 CE: The most recent confirmed eruption began on March 1 and ended on April 30. This event, also a VEI 2, was observed on the east side of Shinzan, west of Kojin-yama.
Volcanic Explosivity Index (VEI)
The Volcanic Explosivity Index (VEI) is a scale used to measure the size of volcanic eruptions. The largest recorded eruption at Chokaisan was a VEI 2, which is considered a moderate eruption. The source records seven VEI observations across the volcano's history.
Current Status
According to the official record, the last known eruption of Chokaisan occurred in 1974. As of the latest data retrieval, the volcano is not currently erupting.
Frequently asked questions
When was the last eruption at Chokaisan?
The last known eruption at Chokaisan occurred in 1974.
What is the largest recorded eruption at Chokaisan?
The largest recorded eruption at Chokaisan was a VEI 2.
How many confirmed eruptions has Chokaisan had?
There are 14 confirmed eruptions recorded in the official source.
Sources and further context
Official datasets support the event-specific facts.