Rocket lies on the floor with a flashlight, reading a book about the deep sea. "The ocean floor is not flat!"
"What did you find?" Raven asks, sitting beside him.
"Mountains! Underwater! And a hole deeper than anything on land!"
Raven leans closer to the map in the book. "What do you notice about the long line down the middle of the Atlantic?"
Nova shines a blue glow on the page like deep water. "Here is a clue," she says. "Some of Earth's biggest features are hidden underwater."
The longest mountain range on Earth is called the mid-ocean ridge. It stretches about 40,389 miles around the globe.
About 90 percent of the mid-ocean ridge is under the ocean.
About three quarters of all the lava on Earth erupts unseen beneath the ocean. Most of it comes out along ridges.
The deepest part of the ocean is the Challenger Deep. It lies in the Mariana Trench in the western Pacific Ocean.
It is about 10,935 meters deep. That is almost 36,000 feet.
| Feature | Where | Fact |
|---|---|---|
| Mid-ocean ridge | under the oceans, around the globe | longest mountain range on Earth |
| Challenger Deep | Mariana Trench, western Pacific | deepest part of the ocean |
Most of Earth's biggest features are hidden underwater.
The mid-ocean ridge is the longest mountain range, and most of it is under the sea.
Most lava on Earth erupts underwater along ridges, where nobody sees it.
| Statement | True or false? |
|---|---|
| The ocean floor is flat everywhere. | ? |
| The Challenger Deep is about 10,935 meters deep. | ? |
| The longest mountain range on Earth is mostly underwater. | ? |
You explored the hidden half of the planet! Tomorrow we see how people stay safer from natural hazards.