Volcanoes Facts for Kids
Explosive facts about volcanoes and geology
When Mount St. Helens erupted in 1980, it blew off the entire top 1,300 feet of the mountain in seconds. The lateral blast was so powerful it knocked down trees 17 miles away.
Kilauea on Hawaii's Big Island is one of the world's most continuously active volcanoes. It erupted almost non-stop from 1983 to 2018 β a total of 35 years.
Most of Earth's volcanic activity actually happens underwater! There are about 30,000 underwater volcanoes called seamounts on the ocean floor.
Shield volcanoes are wide and gently sloping, like an upside-down warrior's shield lying on the ground. They form from runny lava that spreads far and wide before cooling.
Stratovolcanoes (also called composite volcanoes) have steep, cone-shaped sides built up from layers of ash and hardened lava. They tend to produce the most violent eruptions on Earth.
Pyroclastic flows are superheated clouds of gas, ash, and rock that race down a volcano's slopes. They can travel faster than 450 miles per hour β faster than most propeller aircraft.
In 79 AD, Mount Vesuvius in Italy erupted and buried the entire Roman city of Pompeii under 20 feet of ash and pumice in just hours. The city was so perfectly preserved that even loaves of bread were found intact.
The entire ocean floor is made of volcanic basalt rock. Mid-ocean ridges β underwater mountain chains β are places where lava constantly oozes out and creates new seafloor.
Volcanic soil is some of the most fertile on Earth because it is packed with minerals like potassium, phosphorus, and magnesium. Many of the world's best wine regions sit on ancient volcanic soil.
When a volcano empties its magma chamber and then collapses inward, it creates a huge bowl-shaped crater called a caldera. Yellowstone National Park sits inside a giant caldera 45 miles wide.