Hokkaido-Komagatake (Japan): Recorded Eruptions and Historical Activity

Hokkaido-Komagatake is a stratovolcano located in Japan, standing at an elevation of 1,131 meters within a subduction zone and continental crust tectonic setting. Official records from the Smithsonian Global Volcanism Program document a total of 19 confirmed eruptions for this volcano. These events span a vast timeline, stretching from prehistoric activity evaluated through calibrated carbon-14 dating up to historical observations documented in the modern era.

Overview of Eruption History

The confirmed eruption record for Hokkaido-Komagatake includes events evaluated through different evidentiary methods, ranging from isotopic dating for ancient periods to direct human observations for later centuries. The documented activity features a wide range of magnitudes on the Volcanic Explosivity Index (VEI), reaching up to a maximum recorded VEI of 5.0. Across the compiled record of 19 confirmed eruptions, 18 events include assigned VEI values.

Prehistoric activity in the record begins around 4600 BCE, represented by an event with an estimated start-year uncertainty of 50 years and a VEI of 5.0, determined via calibrated carbon-14 isotopic evidence. Subsequent centuries and millennia include intermittent eruptive episodes, with activity distribution shifting heavily into historical and modern centuries.

Chronological Distribution by Century

The recorded eruptions are distributed across various centuries in the official database:

• 46th century BCE: 1 event
• 45th century BCE: 1 event
• 44th century BCE: 1 event
• 17th century CE: 2 events
• 19th century CE: 2 events
• 20th century CE: 12 events

Notable historical events include a large VEI 5.0 eruption that started on July 31, 1640, and concluded on October 9, 1640, documented through reported observations. Later in that same century, a VEI 4.0 eruption occurred from July 4, 1694, to July 6, 1694. Activity continued into the 20th century, which accounts for the majority of the recorded eruptions in the dataset—such as a VEI 2.0 eruption beginning on May 22, 1922.

Latest Recorded Activity

The latest confirmed eruption in the official record began on September 4, 2000, and ended on November 8, 2000, with a recorded VEI of 1.0 based on reported observations. The profile's last-known eruption year is listed as 2000, and the latest confirmed eruption date is September 4, 2000. Official records do not indicate any continuing eruptive activity.