Formed from various kinds of eruptions, the best examples of composite volcanoes are Japan’s Mount Fuji and Italy’s Stromboli. It includes definitions for various key vocabulary for this topic, all clearly defined to aid understanding. One of its most historic eruptions dates back to AD 79 that ruined the Roman cities of Pompeii, Herculaneum, Oplontis, and Stabiae, including several other settlements. In terms of which country has the most volcanoes, the answer is the United States, closely followed by Russia and Indonesia. In addition, about 10 percent of the more than 1,500 volcanoes that have erupted in the past 10,000 years are located in the United States.

Stratovolcanoes tend to form at subduction zones, or convergent plate margins, where an oceanic plate slides beneath a continental plate and contributes to the rise of magma to the surface. The Hawaiian Islands are made of a chain of shield volcanoes including Kīlauea and the world's largest active volcano, Mauna Loa. After cooling, liquid magma may form crystals of various minerals until it becomes completely solid and forms an igneous or magmatic rock. It became the second-largest terrestrial eruption of the 20th century next to Alaska’s Novarupta that erupted in 1912. Sometimes volcanoes build up pressure as the magma emerging from inside the Earth pushes upwards, and this can cause volcanoes to explode with great force.Found in Southeast Asia, when Krakatau erupted in 1883 it released 200 megatrons of energy – that’s the equivalent of 15,000 nuclear bombs. Earthquakes, flash floods, landslides, debris and mudflow (lahar), or acid rain may happen at the same time as a volcanic eruption.

The plates always move very slowly but when the plates move suddenly they often cause an earthquake. Molten lava is quickly placed in a bucket of water to "freeze" the growth of minerals for chemical and microscopic analyses. The total height of Mauna Kea, below and above sea level, is 33,500 feet (10,210 meters), making it taller than even Mount Everest. Our team works with award-winning authors and illustrators to create books that spark the imagination and curiosity of preschoolers and primary-school-aged children around the world.Over geologic time, volcanic eruptions and related processes have directly and indirectly benefited mankind: Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. One such area is the circum-Pacific Ring of Fire , where the Pacific Plate meets many surrounding tectonic plates. An eruption occurs when pressure from gases and the molten lava rock becomes strong enough to cause an explosion.

There is no definitive evidence that an eruption at one volcano can trigger an eruption at a volcano that’s hundreds of kilometers/miles away or on a different continent. Most volcanoes, such as those of Japan and Iceland, occur on the margins of the enormous solid rocky plates that make up Earth’s surface. The red color indicates heat, either from liquid or recently hardened lava still hot enough to glow. Rather, they are studied by many scientists from several specialties: geophysicists and geochemists, who probe the deep roots of volcanoes and monitor signs of future eruptions; geologists, who decipher prehistoric volcanic activity and infer the likely nature of future eruptions; biologists, who learn how plants and animals colonize recently erupted volcanic rocks; and meteorologists, who determine the effects of volcanic dust and gases on the atmosphere, weather, and climate.One feared phenomenon accompanying some explosive eruptions is the nuée ardente, or pyroclastic flow, a fluidized mixture of hot gas and incandescent particles that sweeps down a volcano’s flanks, incinerating everything in its path. Following the 1991 eruption of Mount Pinatubo in the Philippines, cooler than normal temperatures were recorded worldwide and brilliant sunsets and sunrises were attributed to this eruption that sent fine ash and gases high into the stratosphere, forming a large volcanic cloud that drifted around the world. On land, volcanoes are often found along the edges of tectonic plates, and beneath the ocean, they form underwater mountain ranges. Every one of them is different, some erupt in explosions while others have lava that slowly flows out onto the ground. The VEI or Volcanic Explosivity Index has its classifications and description that starts from 0 to 8.