Active volcanoes

The Japan Meteorological Agency (JMA) defines an active volcano as one that has erupted within roughly the last 10,000 years or shows vigorous fumarolic activity today. Japan has 111 active volcanoes, 31 of them in Hokkaido including the Northern Territories.

No more "dormant" or "extinct"

Volcanoes not erupting used to be called dormant or extinct. But volcanoes live long, and a rest of a few hundred years is only a short sleep, so the idea spread of calling every volcano with recorded eruptions, or that may erupt in future, active.

The definition itself has changed: in 1975 it covered volcanoes with recorded eruptions or vigorous fumarolic activity, in 1991 those that had erupted within about the last 2,000 years, and since 2003 those within roughly the last 10,000 years.

Active volcanoes in this catalog

The JMA list of active volcanoes gives the position of each volcano by naming representative peaks. This catalog marks the 20 mountains named there as active volcanoes. Peaks that lie within a volcano but are not named in the list, such as Mount Hokuchin in the Daisetsu group, are not marked.