After a little snack break, Ranger Ben said, "Who's ready to climb a bit higher? We're going to the top, to see the volcano's very own bowl, its crater!"
The children cheered! They carefully followed Ranger Ben up a gentle slope, their boots crunching on tiny bits of rock.
Higher and higher they went, until they reached a wide, open space. Below them was a giant, round hollow, like a giant's empty cereal bowl.
"This is the crater!" Ranger Ben announced. "It's where the lava and ash came out when the volcano was wide awake."
Jill peered over the edge. "It's so big and empty now."
"It is," said Ranger Ben. "But imagine if it were full of bubbly, fiery lava! Now, I brought something special to show you how a volcano can get so much energy."
He pulled out a bottle of fizzy soda and shook it gently. "What happens if I shake it and then pop the top?"
"It'll go 'WHOOSH!'" yelled Leo, excited.
"Exactly!" Ranger Ben popped the top, and soda frothed and sprayed out, making everyone giggle. "Inside the Earth, there's super-hot melted rock called magma. It's like the soda in the bottle."
"And the gas in the magma is like the fizz," Oliver added, understanding.
"You've got it!" Ranger Ben smiled. "When magma rises up, gas bubbles get trapped inside. If too much gas and magma get squished together, the pressure builds up and up, just like in our soda bottle."
"And then the volcano goes 'WHOOSH!'" Leo finished happily, mimicking the soda.