Volcanoes have shaped the Earth’s landscape for millions of years, creating mountains, islands, and fertile soils. However, their eruptions can also bring catastrophic destruction. While many volcanoes remain dormant, some active ones pose significant threats due to their explosive potential, population density around them, and their past history of devastating eruptions. Here are five of the most dangerous volcanoes in the world that could erupt.
1. Mount Vesuvius (Italy)
Located near Naples, Italy, Mount Vesuvius is infamous for its eruption in 79 AD, which buried the Roman cities of Pompeii and Herculaneum under layers of volcanic ash. Today, more than 3 million people live within the vicinity of this volatile volcano, making it one of the most dangerous in the world. Vesuvius last erupted in 1944, and scientists consider it to be an "active" volcano. Its proximity to heavily populated areas, combined with its potential for violent, pyroclastic eruptions, makes it a constant threat.
What makes Vesuvius particularly concerning is the likelihood of a Plinian eruption, characterized by its explosive power and pyroclastic flows that can destroy anything in their path. A major eruption today could have catastrophic consequences for Naples and surrounding communities.
2. Mount St. Helens (USA)
Located in Washington State, Mount St. Helens is known for its catastrophic eruption in 1980, which caused the largest landslide in recorded history and sent ash around the globe. While the 1980 eruption dramatically reshaped the landscape, the volcano has remained active with smaller eruptions and ongoing volcanic activity.
Scientists keep a close eye on Mount St. Helens because it sits along the Cascadia Subduction Zone, one of the most seismically active areas in the United States. The volcano has the potential for another powerful eruption, and although fewer people live in the immediate danger zone, its impact could disrupt the broader region, including Seattle and Portland.
3. Mount Merapi (Indonesia)
Mount Merapi, located on the island of Java, Indonesia, is one of the most active and dangerous volcanoes in the world. The name "Merapi" translates to "Mountain of Fire," and it lives up to this moniker with frequent eruptions. The volcano's proximity to the densely populated city of Yogyakarta and surrounding villages adds to its danger. Over 100,000 people live within its high-risk zone.
Merapi’s eruptions are often accompanied by pyroclastic flows—fast-moving clouds of hot gas, ash, and volcanic material—that can devastate anything in their path. In 2010, an eruption killed over 300 people, displaced thousands, and caused widespread damage. With its frequent activity and potential for violent explosions, Merapi remains a constant threat to the region.
4. Popocatépetl (Mexico)
Popocatépetl, affectionately called "El Popo," is one of Mexico’s most dangerous volcanoes. Located just 70 kilometers southeast of Mexico City, it threatens one of the largest metropolitan areas in the world. More than 20 million people live within its potential impact zone.
Popocatépetl has been continuously active since the mid-1990s, with intermittent ash emissions, lava flows, and small eruptions. Its potential for a large, explosive eruption remains a significant concern. An eruption of this magnitude could severely impact Mexico City, including widespread ashfall, disruptions to air travel, and health risks from airborne particles.
5. Yellowstone Caldera (USA)
While technically not a traditional "volcano" in the sense of a mountain, the Yellowstone Caldera in Wyoming is one of the most dangerous volcanic systems on the planet. The Yellowstone supervolcano, located in Yellowstone National Park, is a massive volcanic system that has erupted three times in the past 2.1 million years. A supereruption at Yellowstone could eject hundreds of cubic kilometers of volcanic material into the atmosphere, causing a "volcanic winter" by blocking out sunlight, leading to a global drop in temperatures.
Although scientists believe a supereruption is unlikely in the near future, the catastrophic potential makes Yellowstone one of the most closely monitored volcanic areas in the world. If it were to erupt, the consequences would be felt globally, with widespread crop failures, climate disruptions, and enormous human and economic losses.
Volcanic eruptions are among the most powerful natural disasters, and some of the world's most dangerous volcanoes could erupt with devastating consequences. These five—Mount Vesuvius, Mount St. Helens, Mount Merapi, Popocatépetl, and Yellowstone—are all ticking time bombs. Monitoring and early warning systems are critical in reducing the risk to human lives and property, but in many cases, the sheer scale of these potential eruptions means that the impact would be global. While we cannot predict exactly when these volcanoes will erupt, their potential makes them some of the most dangerous in the world.
The world below sea level is little explored. This is perfectly demonstrated by recent seabed surveys, where over 19000 unknown underwater mountains and volcanoes have been discovered using radar satellite data.
We usually learn about underwater volcanoes when they manifest their existence in a spectacular way - through an eruption. Meanwhile, as it turns out, there is a method by means of which we can detect them even before they emerge from the water. And on a massive scale.
A team of oceanographers from the Scripps Institution of Oceanography, in collaboration with scientists from Chungnam National University and the University of Hawaii, discovered over 19000 previously unknown underwater volcanoes or mountains. This work is critical to better understanding the ocean floor, improving modeling of ocean currents and ensuring safer underwater navigation.
The results of the research were published in the journal "Earth and Space Science" (DOI: 10.1029/2022EA002331).
Researchers from these institutions have succeeded in developing a method for mass detection of underwater volcanoes and mountains. But to understand exactly what it is, we must first look at how the ocean floor is shaped and why it is so important to know it thoroughly.
On dry land, what stands out in the landscape are, of course, the mountains. And their counterpart in the form of undersea or seamounts also exists at the bottom of the ocean. They are formed either as a result of tectonic movements or volcanic activity.
However, the existence of seamounts is not completely without influence on human functioning. Considering the fact that so far we have mapped only about 25 percent of the world with sonar. ocean floor, we know very little about where they might be. And this, in turn, can be a problem for submarines, for example. There have already been cases in which, for example, American ships collided with such mountains. This is also a problem for scientists who are unable to accurately predict the directions of water flow in the oceans. Because when sea currents hit such a place, the water carried by them is pushed upwards.
New bottom maps
Experts set themselves a rather difficult task of discovering as many seamounts as possible. For this purpose, they decided to use data collected by radar satellites. Of course, they do not serve this purpose in themselves, but you can use the fact that they measure, for example, the height of the ocean surface, which in turn changes depending on the gravitational pull associated with the topography of the bottom. And in this way it became possible to find as many as 19325 previously unknown seamounts, i.e. potential volcanoes. The discovery extended a previously published catalog of 24643 seamounts to a total of 43454.
In addition to the benefits listed above, discovering so many mountains can also be useful for the mining industry. This is because in such places you can often find significant amounts of rare minerals. However, it will also serve to better map the course of tectonic lines, as well as the geomagnetic field. It will also be important for the study of the underwater ecosystem, because the vicinity of underwater mountains is also a friendly environment for ocean fauna and flora.