- The biggest volcano in the world is the Mauna Loa, in Hawaii. It rises off of the seafloor to 13,000 feet above sea level or about 29,000 feet above the seafloor
- Most volcanoes are 10,000 to 100,000 years old
- There are at least 1,500 active volcanoes around the world
- Indonesia has the most volcanoes about more then 200 alive
- Common volcanic gases include water vapor, carbon dioxide, sulfur dioxide, hydrogen chloride, hydrogen fluoride and hydrogen sulfide
- Volcanic eruptions can send ash high into the air, over 30km (17 miles) above the Earth’s surface
- The lower 48 states in the U.S. have about 40 volcanoes
- Scientists has estimated the ocean contains 10,000 volcanoes
- The oldest volcano is the Etna at 350,000 years old
- About 500 million people live close to active volcanoes
