Volcano Facts for Kids

You probably think Mount Everest is the world's tallest mountain-but this is actually tricky!

While Everest is the highest point above sea level at 29,029 feet, the shield volcano Mauna Loa in Hawaii is 30,085 feet tall when measured from its base on the ocean floor to its peak.

That makes Mauna Loa about 1,000 feet taller than Everest! Most of this giant is hiding underwater.

The confusion is over-we have two names for the same awesome stuff!

When the melted rock is trapped underground, like deep in a secret chamber, we call it magma.

The second it bursts out of a vent onto the Earth's surface, it gets a new name: lava! It's the same liquid rock, just at a different address.

How hot are we talking? Lava temperatures range from about 700 to 1,200 °C (1,300 to 2,200 °F)!

That is way hotter than the hottest oven your parents might use, which might hit 260 °C (500 °F).

The hottest flowing lava, like basaltic lava in Hawaii, can be near 1,250 °C!

When Mount Vesuvius erupted in 79 AD, it didn't just pour lava; it unleashed a pyroclastic flow!

This was a super-fast, ground-hugging avalanche of hot gas, ash, and rock fragments that buried the city of Pompeii.

The eruption shot material up 33 km (21 miles) into the air before the deadly flows rushed down the slopes.

Want to know how scary fast a pyroclastic flow is? They can travel at speeds of 160 km (100 miles) per hour!

That's faster than the top speed of most cars on the highway! Scientists found out they glide on a thin layer of gas they create themselves.

This air-lubrication layer lets the scorching hot mixture slide with almost zero friction.

Imagine a giant horseshoe shape ringing the Pacific Ocean-that's the Ring of Fire!

This area is a hotspot for geological drama, housing between 750 and 915 active or dormant volcanoes.

It also causes about 90% of all the world's earthquakes-wow, that's a busy place for plate tectonics!

The famous geysers of Yellowstone National Park sit on top of a supervolcano!

Its last supereruption happened about 630,000 years ago, creating a huge crater called a caldera that is 30 by 45 miles across.

Don't worry-the most recent activity was just a smaller lava flow about 70,000 years ago.

Not all volcanoes are steep cones! Shield volcanoes look like a warrior’s shield lying on the ground.

They are built by very fluid lava that flows easily, spreading out over huge distances.

For example, Mauna Loa has slopes of only about 12 degrees at their steepest-that’s barely a hill compared to some mountains!

Geysers are basically volcanoes that 'burp' hot water and steam, and the tallest one is Steamboat Geyser in Yellowstone!

Its biggest recorded eruption on July 19, 2020, shot water up a staggering 137 meters (449 feet).

That’s taller than a 40-story building! It erupts totally randomly, sometimes days apart, sometimes after 50 years!

The eight main Hawaiian Islands you see are just the visible tops of a chain with more than 129 volcanoes!

This massive Hawaiian Ridge-Emperor Seamounts chain stretches for about 6,100 km (3,800 miles) across the Pacific.

The volcanoes get older the further northwest you go-the oldest one is 81 million years old!