Volcanoes in Japan

In short

What “active” means

In Japan, an active volcano is a volcano that has erupted within about the last 10,000 years, or that now has active fumaroles (vents giving off volcanic gas).

In 2003, the Coordinating Committee for Prediction of Volcanic Eruptions set this definition.

From 108 to 111

At first there were 108 active volcanoes under this definition. Two more were added in 2011 and one in 2017, so there are now 111.

No more “dormant” or “extinct”

In the past, only volcanoes erupting now were called active. Volcanoes such as Mount Fuji, with eruptions in written history but quiet now, were called “dormant”, and those with no recorded eruptions were called “extinct”.

But volcanoes live a very long time, and a rest of a few hundred years is only a short sleep. From the 1950s, the idea spread around the world of calling every volcano that has erupted in the record, or may erupt in the future, an active volcano.

Think about it

• Q1Why is 10,000 years a better yardstick than “erupting now”?
• Q2Mount Fuji was once called “dormant”. What is it called now, and why?
• Q3Are there volcanoes in your country? When did they last erupt?

There is no single right answer. Talking it over with someone at home is a good way to learn.