Sure! So you know how sometimes, when you're boiling water on the stove, little bubbles start to form and rise up to the top? Well, imagine if the water was the ocean and the bubbles were coming from a mountain underneath the water. That's what a submarine volcano is!
It's a special kind of volcano that's hidden under the sea. It's just like any other volcano you might see on land, but it's covered by water. Sometimes, these volcanoes can be really big and create mountains and islands in the ocean!
When a submarine volcano erupts (which means it shoots out hot lava and gas), it can be really dangerous for the animals that live in the ocean nearby. But it's also really awesome and scientists can learn a lot from studying them!