Longest-Running Volcanic Eruptions Active in 2025

What this chart shows
The eruptions that were active during 2025 and had lasted at least 11 full years, ranked by their length in years. All but one were still continuing at the Smithsonian's last data update; the exception is Erta Ale in Ethiopia, whose eruption ended in August 2025.

How the data is collected
The lengths are the "Eruption Years" figures from the Global Volcanism Program's list of the longest eruptions, which covers eruptions that started in 1800 or later and lasted at least 60 consecutive months. Only eruptions that also appear on its list of eruptions active during 2025 were kept. For continuing eruptions, the length runs to the latest stop date the database gives, in March 2026.

Background
The Smithsonian counts eruption months from the start date to the stop date and converts them to full years. Pauses shorter than three months do not break an eruption, but renewed activity after more than three months of inactivity is recorded as a new eruption. Yasur in Vanuatu is left off the list because it has no clear start date; the program notes that Captain Cook saw it erupting in 1774 and that the same style of activity may have begun around 1270 CE.

Limits
Start dates for older eruptions carry uncertainty, and some are recorded only as "in or before" a given date, so the true lengths may be longer. The ranking measures how long activity lasted, not how much material was erupted. Because continuing eruptions are measured to March 2026, their figures run a few months past the end of 2025.