Myokosan (Japan): Recorded Eruptions and Historical Activity

Myokosan is a stratovolcano located in Japan at an elevation of 2,454 meters, situated in a subduction zone and continental crust tectonic setting. According to official records from the Smithsonian Global Volcanism Program, the volcano features 10 confirmed historical eruptions spanning from ancient history up to 750 BCE.

Overview of Historical Activity

The historical record for Myokosan spans multiple centuries BCE, compiled through scientific methods such as calibrated radiocarbon dating and tephrochronology (the analysis of ash layers). The earliest recorded eruption in the collection occurred around 4750 BCE, with a stated uncertainty of 300 years. Subsequent confirmed eruptions are documented across various centuries leading up to the latest recorded eruption in 750 BCE.

Where available, the Smithsonian Global Volcanism Program records provide specific dating evidence methods for individual events. For instance, the earliest event relied on calibrated 14C isotopic dating, while several subsequent eruptions throughout the timeline were identified using tephrochronology correlations.

Chronology of Confirmed Eruptions

The table below summarizes representative confirmed eruptions from the official record, illustrating the timeline and evidence methods associated with Myokosan's historical activity.

Among the recorded events, the largest assigned Volcanic Explosivity Index (VEI) reaches a value of 5.0. The VEI scale describes the relative size and explosiveness of volcanic eruptions based on criteria such as volume of products ejected, though it does not serve as a complete measure of total damage or local danger.