A volcano is an opening in the earth’s crust through which lava, volcanic ash, and gases escape. Beneath a volcano, liquid magma containing dissolved gases rises through cracks in the Earth’s crust. As the magma rises, pressure decreases, allowing the gases to form bubbles.
1. Kelud Volcano, Indonesia
Famed for its dangerous and aggressive eruptions, Kelud killed at least 5160 people in the 1919 eruption when the (then very large) crater lake drained and formed lahars that killed at least 5160 people. Another major explosion took place in 2014, with a huge column of ash drifting over the Indian Ocean. Kelud is thought to have erupted more than 30 times since the year 1000. Isn’t that scary?
2. Galeras Volcano, Colombia
Galeras, located near the city of Pasto is one of Colombia’s most active volcanoes, with at least 20 eruptions since the 1500s. Approximately 400,000 people live within the volcano’s zone of influence which makes it scarier as their life dangles on a thin line between life and death. Historically, an eruption killed 9 people, 6 of whom were scientists studying the volcano in 1993. There were also two documented eruptions in 2010.
3. Campi Flegrei, Italy
It’s true this volcano has not erupted since 1538, but its sheer aggression should provide a conspicuous reminder that it can happen again. Scientists believe that if it does occur, the strength would be between 100 and 1,000 times greater than the devastating Mount St. Helens eruption of 1980.
4. Kilauea Volcano, Hawaii
Popocatépetl is the second most active volcano in Mexico. In terms of explosive activity and population threat, it ranks highest in Mexico and North America. One of the 10 most-populated volcanoes in the world, Popocatépetl has around 30 million people living within a 70 kilometre radius of its 5,452-metre summit.