Active Volcanoes Around the World

A volcano is considered active if it has erupted within the last 10,000 years (the Holocene epoch) and is expected to erupt again. Volcanologists generally recognize around 1,350 potentially active volcanoes worldwide, though definitions vary between agencies. An active volcano may be erupting right now, or it may be in a quiet phase between eruptions — what scientists call a repose period.

A dormant volcano is one that is not currently erupting but has erupted in recorded history and retains the potential to erupt again. Think of dormancy as a long sleep rather than permanent retirement. Mount Fuji, which last erupted in 1707, is a classic example. Dormant volcanoes can awaken with little warning, sometimes after centuries of silence, making them particularly dangerous because communities may not expect or prepare for an eruption.

An extinct volcano is one that scientists believe will never erupt again. It has been cut off from its magma supply, and the tectonic conditions that fed it no longer exist. However, the distinction between dormant and extinct is not always clear. Several volcanoes once considered extinct have erupted unexpectedly — Mount Pinatubo in the Philippines had no recorded eruptions for 500 years before its catastrophic 1991 blast.