When we say active volcanoes could explode at any minute, that may be a stretch, but the thing that makes some of the world’s most active volcanoes so interesting is the element of unpredictability. Technically, an active volcano doesn’t mean that it’s spewing lava and erupting every couple of years, instead, volcanologists use this term to describe the volcano if it has erupted at least once during the past 10,000 years, Volcano Discovery reports.

After laying dormant for hundreds of years, there could be another volcanic eruption, as proven by Iceland’s Eyjafjallajökull (which is also the volcano responsible for the air travel disruptions in 2010), while other volcanoes have persistent, low-level activity. And then there are the truly dangerous and fascinating volcanoes, those that pique the interest of volcanologists because there is no stopping them. These volcanoes, like Mount Pinatubo and Kīlauea, are considered especially dangerous because of their destructive eruptions, although Time points out that there are a number of contributing factors when attempting to determine which volcanoes are a higher risk, and these include population density and the type of magma.

Below are 20 active volcanoes across the world that have an interesting geological history, and could erupt again at some point in the future, leaving destruction in their wake.

20 Hawaii's Kīlauea Is Considered To Be The World's Most Active Volcano

Some consider Kīlauea to be the most active volcano in the world, and most recently, in 2018, it started spewing lava again. According to CNN, the volcano has been active since 1983 and has 61 recorded eruptions.

Kīlauea is one of several active volcanoes on the Hawaiian islands and is located on Hawaii’s Big Island. Its frequent eruptions have resulted in the loss of life and evacuations, in addition to the damage that has been caused to homes, rainforests and highways, Atlas & Boots reports. While CNN reports that the lava has physically changed the island, resulting in hundreds of acres of new land.

19 Mount Etna Is A Place Of Outstanding Universal Value

The active stratovolcano known as Mount Etna is located in Italy’s east coast of Sicily, and is the highest volcano in Europe, measuring 3327 meters high, Visit Sicily reports.

Interestingly, Mount Etna has also been listed on the UNESCO World Heritage Site for its’ outstanding universal value. The reason for this, according to UNESCO, is because the volcano is of the world’s most active volcanoes and is known for its level of activity which makes it, an “outstanding example of ongoing geological processes and volcanic landforms.”

18 Mount Vesuvius Is The Volcano Responsible For The Destruction Of Pompeii

Mount Vesuvius is located on the Gulf of Naples and is one of the more well-known active volcanoes in the world because it is believed to be responsible for one of history’s most catastrophic eruptions, which led to the destruction of Pompeii.

The event happened in 79 AD, and the volcano is still considered one of the most active and dangerous in the world. And according to How Stuff Works, volcanologists believe it could be overdue an explosion. The publication notes that there are hundreds of thousands of people living in the red zone area, and the Italian government has devised an evacuation plan in the volcano ever erupted again.

17 The Sarychev Peak Eruption In 2009 Was Photographed From Space

Russia’s Kuril Islands are home to the Sarychev Peak, a volcano which has been the subject of some of the most interesting photos. During the early stages of an eruption on June 12 of 2009, photos were taken of the volcano by an astronaut onboard the International Space Station.

According to NASA, this photograph was “exciting to volcanologists” because it gave a glimpse into the early stages of the volcanic eruption. Sarychev Peak is one of the most active volcanoes on the Kuril Islands, and prior to 2009, it also erupted in 1989, 1986, 1976, 1954 and 1946.

16 Mount Pinatubo Lay Dormant For 600 Years Before Erupting Back To Life

Mount Pinatubo is located in central Luzon in the Philippines and is considered one of the most dangerous active volcanoes after its series of eruptions in 1991. According to Britannica, this was the volcano's first eruption for 600 years, and resulted in significant damage, as the heavy ashfalls left hundreds of thousands of people homeless and caused several hundred people to lose their lives.

U.S Geological Survey referred to the eruption as the second-largest volcanic eruption in this century. The site also notes that even years later, the effects of the explosion were still being felt and the “valley-filling pyroclastic-flow deposits” had retained much of its heat.

15 Popocatépetl Is An Attraction To Be Viewed From Afar

Mexico’s Popocatépetl has become an attraction to view from a distance, and experienced its last known eruption in 2018 when it sent a huge ash plume into the sky. But according to the Smithsonian Institution, frequent eruptions have been reported since the 14th century.

The volcano is located 70 km south-east of the capital, Mexico City, and according to Volcano Discovery, after being dormant for over 50 years, Popocatépetl erupted in 1994 and has continued to erupt at irregular intervals ever since. BBC notes that this has, at times, resulted in travel delays, like the eruption in 2013, which caused airlines to cancel scheduled flights.

14 Campi Flegrei Has Become The Subject Of A Study As Scientists Determine When It Could Erupt Again

The Campi Flegrei volcano made headlines in 2018 after it became the topic of a study published in Science Advances, which noted that molten rock (magma) under the volcano had been building up towards an eruption, The Verge reports. However, the timeline of events relating to the eruption of this volcano -- which is located on the western edge of Naples -- remains unclear, and the publication notes that volcanic eruptions can take thousands of years.

National Geographic reports that the most recent event Campi Flegrei had was in 1538.

13 Sakurajima Is Continually Monitored Because Of It's Close Proximity To A City

Japan’s Sakurajima (located in southern Kyushu) was making headlines as recently as November of 2018 because it once again became engulfed in lava. According to Express, this is the third event in 2018 in which the volcano, which stands over 1,400 meters high, has erupted.

The activity of Sakurajima has been recorded for hundreds of years, but according to Volcano Discovery, the largest historical eruptions occurred between 1471 and 1476, and more recently, in 1914. It is a volcano that is continually monitored because of its close proximity to the city of Kagoshima.

12 Iceland's Eyjafjallajökull Was Responsible For Days Of Air Traffic Disruptions

If your air travel was disrupted in 2010, then you may have had Eyjafjallajökull to blame.

The volcanic eruptions of Iceland’s volcano created travel issues because of volcanic ash which was thrown into the atmosphere, Iceland Travel reports. This resulted in flights being grounded in north-west Europe and the closure of airspace over many European countries leaving thousands of travelers stranded over the course of six days.

Prior to this event, not many people knew about this volcano because according to The Guardian, the 2010 event was Eyjafjallajökull’s first major eruption since 1821, having lain dormant before then.

11 The Island Of Ambrym Is Home To Two Active Volcanoes

Ambrym is a volcanic island in Vanuatu that has become a popular tourist destination and according to Lonely Planet, the island contains two twin volcanoes, Mt. Marum and Mt. Benbow. Travelers to this area typically choose to climb the volcanoes, and because the area lacks roads, the best way to explore is by foot or boat.

According to Ambrym Travel, the two volcanoes have created a caldera (a cauldron-like hole) of 10 to 12 km in diameter in the middle of the island, and their activity has resulted in multiple evacuations over generations.

10 Mt. Cleveland In Alaska Has Regularly Erupted During The Millennium

Mount Cleveland, or Cleveland Volcano as it’s also known, is located in the Aleutian Islands and according to Geology, it is one of the most active volcanoes in the region.

The volcano, which rises to an elevation of 1,730 meters, has had regular activity and a series of eruptions since 2000. These eruptions have resulted in air traffic disruptions because volcanic ash can cause significant damage to an airplane and can result in engine failure. In fact, it is these ash plumes which poses the most danger, because the island is uninhabited.

9 Mount Erebus Constantly Sputters Lava And Hot Gases

It may seem strange to have a volcano that has the potential to spew molten lava in one of the coldest parts of the world, but Antarctica's Mount Erebus is the world’s southernmost volcano, Atlas Obscura reports.

Mount Erebus is a much-studied one, and according to the Smithsonian it “constantly sputters hot gas and lava.” The volcano was first discovered in 1841 during an expedition by explorer Sir James Clark Ross, who named Erebus, and Mount Terror, the volcano located next to it, after his ships (H.M.S. Erebus and H.M.S. Terror), National Geographic reports.

8 Indonesia's Mount Agung Poses A Major Risk To The People Living Near It

Indonesia is home to several active volcanoes, and Mount Agung is among them. Located in Bali, Mount Agung's most recent major event, according to Time, took place in 1963 and lasted for 11 months. The eruption resulted in significant loss of property, but more than 1,000 people also lost their lives.

Then, after more than 50 years, the volcano made headlines in 2017, when according to MSN, it started spewing lava and plumes of smoke. The eruptions of Mount Agung have been ongoing, and in 2018, an eruption resulted in the evacuation of residents living on the slopes and caused disruption to air travel, Express reports.

7 Mount St. Helens Caused More Than $1 Billion In Damage During A Single Eruption

The 2,550-meter tall stratovolcano Mount St. Helens is a volcano located in southwestern Washington, and it has attracted much attention from volcanologists. It also claimed the life of volcanologist David Johnston, during an eruption in 1980, who was on a U.S. Geological Survey (USGS) base on the side of the volcano, Express reports.

It was this year that the volcano caused more than $1 billion in damage and claimed the lives of 57 people, many of which were the result of asphyxiation due to hot ash.

6 There Are Millions Of People Living In The Red Zone Of Mount Merapi

Mount Merapi (which means mountain of fire) is one of Indonesia’s most active volcanoes, out of its 130 active volcanoes, Britannica reports. There have been multiple major eruptions throughout history, including an eruption in 1994, which claimed several lives, and again in 2010.

What makes this volcano of interest is the area surrounding the volcano is densely populated, with more than 24 million people calling it their home, Time reports. This poses an issue with regards to evacuation and makes Mount Merapi one of the most dangerous volcanoes in the world.

5 The Piton de la Fournaise Has Become A Much Loved And Visited Attraction

Located on the Reunion Island is the Piton de la Fournaise, or Peak of the Furnace volcano. It rises up 2632 meters from sea level, and according to France, it takes up a third of the island’s surface.

Piton de la Fournaise has become one of the most visited attractions on the island, and is also one of the world’s most active volcanoes; in the last ten years, it has erupted, on average, every nine months. Although there is frequent activity, Volcano Discovery reports that the eruptions are short and pose little threat to humans as the active areas are uninhabited.

4 Volcán Pacaya Has Erupted Almost Every Year Since 1999

Guatemala has 22 volcanoes, another of which we will mention later, but the Volcán Pacaya, located near the city of Antigua, is one of the few active volcanoes left in the country, Earth Magazine reports. The volcano's activity has been recorded, with the publication noting that there have been 48 eruptions since 1565, and more recently, in 1999, the activity began to increase. Since then, there has been an eruption almost every year.

But that doesn’t stop tourists flocking to the destination, and Volcán Pacaya is a popular hiking destination, Bucket List Journey reports.

3 Paektu Mountain Is Considered By North Koreans To Be A Sacred Site

Located on the border of China and North Korea, the Paektu Mountain is considered a sacred place by North Koreans, ABC reports. The active volcano rises 2,750 meters above sea level and has attracted tourists from across the globe, with the publication noting that a New Zealand-born hiker has been taking Western tour groups on a hiking tour of the region.

The National Geographic reports that the mountain has been dormant, but there was a time when it caused one of the largest eruptions in recorded history. Scientists are now studying the volcano, searching for magma to determine if it will erupt again.

2 Galeras' Has Been Active For A Million Years

Galeras is considered one of Columbia’s most frequently active volcanoes, and although activity has been recorded here since the 16th Century, Geology reports that this volcano has been erupting for more than a million years. This volcano is particularly dangerous to humans because of its close proximity to the city of Pasto, and the publication reports that at least 300,000 people in the area would find themselves in trouble were Galeras to erupt again.

In 1993, the volcano made headlines after erupting while a group of tourists and volcanologists were inside its crater, Volcano Discovery reports.

1 Santa María Is Responsible For One Of The Biggest Eruptions In The Twentieth Century

Another of Guatemala’s active volcanoes is Santa María, a large stratovolcano with an elevation of 3772 meters, Oregon State University reports.

Located in the country’s western highlands, Santa María is responsible for one of the biggest eruptions of the twentieth century, Geology reports. This happened in 1902, after a series of earthquakes, and Santa María began to erupt. It lasted for several weeks spreading tephra as far as Mexico.

After this event, a crater formed, and two decades later in 1922, a dacite lava dome called Santiaguito formed in the crater, according to Oregon State University, the activity is ongoing.

References: Volcano DiscoveryAtlas & Boots, CNN, UNESCO, Visit Sicily, How Stuff Works, NASA, Britannica, USGS, Smithsonian Institution, BBC, The Guardian