How Do Volcanoes Actually Work?

Morning Volcanoes!

You know how volcanoes… EXPLODE?!?

Why do they do that?

Well, cut the Earth in half:

See all that orange stuff in there? That's the mantle, which is basically just really hot rock.

Then, right around the edge, there's the Earth's crust:

A hard, rocky outer layer… AKA where we all live.

So a volcano is basically just a rupture in this crust…

How do these ruptures form?

Well, remember the crust we all live on is actually broken up into giant slabs known as tectonic plates.

And they all fit together like a puzzle…

Here's the thing… If you look at a map of Earth's volcanoes, a LOT of them seem to be found along the edges of these giant tectonic slabs.

This is because these plates are… MOVING!

Albeit very, very slowly.

For example, the Pacific and Eurasian plates are moving towards each other at like 3 inches per year.

The Pacific Plate is mostly ocean.

But the Eurasian Plate? It’s mostly land.

So, as they inch closer—super slowly—the heavier Pacific Plate dives under and sinks under the Eurasian Plate, melting into the hot mantle below.

AKA a Destructive plate boundary.

As the Pacific plate sinks below the Eurasian plate, it forces magma upwards with a lot of pressure that can eventually break through the crust.

This type of boundary causes the MOST volcanoes.

If you look at the volcano map again, you’ll notice there are hundreds of volcanoes littered around the Pacific plate.

Something scientists have dubbed “the ring of fire”…

But other types of plate boundaries form volcanoes too.

Like the one between the North American and Eurasian plates, which are slowly moving apart.

Meaning magma can bubble up into that gap… creating a volcano.

Or there are the volcanoes that AREN’T on plate boundaries, called hotspot volcanoes.

The best example of this is right here:

Yes, really… Hawaii is a hotspot volcano.

So magma just straight up melts a tiny hole in the crust and eventually breaks through!

Which is exactly how the islands of Hawaii formed over millions of years.

But how do volcanoes actually… ERUPT?

Well, regardless of how it formed, all volcanoes are kinda similar.

Beneath the volcano lies a giant magma chamber.

Magma is forced into this chamber from the Earth’s mantle, where it collects and builds up pressure.

This pressure builds up and up and up…

Until eventually the tip of the volcano can’t take it anymore… and EXPLODES!!

Releasing ash, dust, gases, and lava!

Stay Cute,
Reece, Henry & Dylan 🌈

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