The Most Active Volcanoes in the World—And Which Countries Have Most

The recent eruption of Italy's Stromboli volcano has the potentially deadly natural phenomenon on everyone's radar as Hawaii's Mauna Loa is also displaying signs of increased seismic activity.

Stromboli and Mauna Loa are two of the world's most active volcanoes.

There are about 1,350 potentially active volcanoes in the world, according to the United States Geological Survey (USGS). But not all the active volcanoes in the world have erupted recently. The USGS estimates that around 500 of Earth's active volcanoes have erupted in historic times.

Dave McGarvie, a volcanologist and honorary researcher at Lancaster University in the United Kingdom, told Newsweek that the term "active" often causes confusion.

"It would be simpler if everyone agreed to use the term 'active' to describe a volcano that is actually erupting or at least has magma bubbling away in a lava lake. And if we all agreed that 'dormant' is used for a volcano that is currently quiet but is very likely to erupt again in the future. And we agree that a third term, 'dead,' refers to a volcano that is almost certainly never going to erupt again," McGarvie said.

"One of the issues is that 'dormant' periods for different volcanoes vary hugely. Some volcanoes with lava lakes, for example Villarrica in Chile, are almost never dormant, but as the lava sits confined within a summit cone and just heaves and spurts a bit, it's fairly harmless and becomes a huge attraction for tourists prepared to hike to the top of this snow-capped volcano.

"When it becomes more active, it's not safe to be anywhere near the summit, as then there are explosions, lava fills the crater and flows down the sides, and there can be water floods which can turn into mudflows which have in the past killed people and destroyed properties around Villarrica. Other volcanoes, especially large ones such as Yellowstone and Long Valley (both U.S.), can have dormant periods that last several hundreds of thousands of years—and yet we don't consider them 'dead'—we are confident that they will erupt again at some time in the future."

While it would be impossible to list all of Earth's active volcanoes, here are some of the most notable.

Kīlauea, Hawaii, U.S

Kīlauea—located to the southeast of Hawaii—is not only one of Earth's most active volcanoes, but also one of the most dangerous. It last erupted in September 2021. Kīlauea is estimated to have caused around 400 deaths in total.

It is considered one of the most dangerous volcanoes in the U.S., with the highest "threat score" of any of the active volcanoes in the country. This is based off factors such as eruption recurrence, volcano type, historic unrest and the ground-based population at the site.

Mauna Loa, Hawaii, U.S

Mauna Loa is another of the five volcanoes that makes up Hawaii.

It is the largest volcano on the planet and is also considered one of the most active volcanoes on Earth. Mauna Loa rises 13,000 feet above sea level.

The volcano has recently been under supervision after it showed shows of heightened unrest. On October 5, the National Park Service announced the summit would be closed until further notice due to the increase in seismic activity. Mauna Loa last erupted from March 25 to April 15, 1984, following nearly two years of increased seismic activity.

Stromboli, Italy

Stromboli, located off the north coast of Sicily, is so active that it has been erupting almost continuously since 1932. Its last notable eruption was in October 2022. Thankfully, nobody was killed.

Fagradalsfjall, Iceland

Fagradalsfjall, located 40 kilometers from Reykjavík, had not erupted for 6,000 years before it then erupted for two years in a row in 2021 and 2022. Its last eruption began on August 3, 2022, just six months after the previous one.

McGarvie said that while Iceland has "many active volcanoes," deaths caused by them are relatively few.

"Iceland now has an excellent network of volcano monitoring stations, and the ability to deploy extra equipment when volcanoes show unrest, and a higher level of monitoring is needed. And they have good scientists, plans for many likely eruption and evacuation scenarios, and protocols to ensure that the various agencies work effectively together," he said.

Mount Merapi, Indonesia

Mount Merapi is located on the border of Central Java. It has erupted regularly since 1584 and is one of the most active volcanoes in the country.

Villarrica

Villarrica is one of Chile's most active volcanoes. It watches over a town of the same name located 750 kilometers south of Santiago.

"Chile has a fairly good network of volcano monitoring stations, though it is always a challenge maintaining these so that there is good coverage all the time. Hazard maps have been produced for many volcanoes, and there are good alert procedures in place for the volcanoes that erupt most frequently, such as Villarrica," McGarvie said.

What Country Has the Most Volcanoes?

Indonesia is the country with the most active volcanoes. It is also where volcanoes have caused the most fatalities.

Other active volcanoes in Indonesia include Sinabung, Ibu, Dukono, Semeru, and Lewotolo.

The United States also has a high number of the Earth's volcanoes. The U.S. is home to 162 volcanoes, with 42 remaining active.

Are Active Volcanoes Always Dangerous?

While many volcanoes can be considered active, many of them are not considered among the world's most dangerous. What exactly constitutes a dangerous volcano also remains debatable among scientists.

"There are too many dangerous volcanoes to list, but some that I personally consider particularly dangerous include Whakaari (White Island) in New Zealand. This island is just the very accessible top crater of an active volcano, and an eruption in 2019 killed 22 people and badly injured others," McGarvie said. "It is not a volcano that I would ever personally visit, due to the inherent instability of the material within the crater, and the risk of a sudden steam blast and/or eruption."

McGarvie said he would also personally never visit Hekla—a volcano in Iceland that is "not what many people would consider a dangerous volcano, as it does not produce eruptions that regularly endangers lives."

"But much as I love getting to the tops of volcanoes, I would not go to the summit of Hekla because it has a reputation of giving very little warning that it is about to erupt—sometimes as little as 25 minutes," McGarvie said.

"Other 'dangerous' volcanoes include those that have a track record of erupting two to three times in a generation in countries where there aren't the resources to adequately monitor each volcano, and so the signals that a volcano is showing unrest that may lead to an eruption are missed, and so it can erupt apparently without warning."