The eruption of Mt. Tambora in Indonesia in 1815 was the most destructive explosion on Earth in the last 10,000 years. It was 100 times more powerful than the eruption of Mt. Vesuvius, and affected the weather all over the world, making snow fall on the 4th of July - in Virginia!

Underneath the Earth’s crust, it’s really, really hot. So hot that it melts some of the rock, turning it into liquid magma. Liquid rock is lighter than solid rock, so it floats upwards (sort of like how ice floats! Except, you know, the opposite of that). The liquid magma pushes up, and up, and up, until it finds cracks in the Earth’s surface to burst through. That’s a volcanic eruption!

The largest volcano in the Solar System is Olympus Mons on Mars. Olympus Mons is as wide as the state of Arizona, and nearly 3 times taller than Mt. Everest! Olympus Mons is a shield volcano, like Mauna Kea in Hawaii, so it’s very wide and flat-shaped (like a shield!).

In 1943, a cornfield in Mexico suddenly erupted, giving birth to Parícutin, the youngest volcano in the world. For weeks leading up to the eruption, residents reported hearing thunder in a cloudless sky, and experienced several earthquakes a day. Parícutin would continue to erupt and grow for the next 9 years. Now dormant, Parícutin is 9,200 feet high and a tourist attraction.

The Thrihnukagigur Volcano in Iceland can be visited by tourists during a short period in the summer (Don’t worry - it hasn’t erupted for 4,000 years). Tourists can go deep inside and even see the massive magma chamber, where the magma once collected between eruptions.

Lava can travel up to 6 mph, or about as fast as the average jogger. Usually, though, it’s much slower - about 1 foot every second. Which is good, because if you see lava coming, you need to get out of the way!