How much do you know about our oceans? Test your knowledge with these 10 fascinating and fun science facts.

1. The Earth’s oceans hold about 96.5% of all of Earth’s water and around 70% of the Earth’s surface is covered by oceans. What’s more, about 70% of the oxygen we breathe is produced by our oceans.
2. The largest ocean is the Pacific Ocean which covers around 30% of the Earth’s surface. The Atlantic Ocean is the second largest ocean and covers over 21% of the Earth’s surface. The third largest ocean is the Indian Ocean and covers around 14% of Earth’s surface.
3. 94% of all life on Earth exists in the oceans. But we have only explored about 5% of the Earth's oceans - about ⅔ of marine life remains unidentified and there are many marine life forms yet to be discovered.
4. Ocean tides are caused by the Earth rotating while the moon and sun’s gravitational pull act on the water.
5. The deepest known area of the Earth’s oceans is the Mariana Trench in the Pacific Ocean. Its deepest point measures 11,000m.
6. The longest mountain range in the world is the Mid-Oceanic Ridge. It is an underwater mountain chain that stretches over 56,000km.
7. The ocean is home to the world’s largest living structure, the Great Barrier Reef. It is the largest coral reef in the world and is located off the coast of Australia. It measures around 2600km and can be seen from the moon.
8. The Pacific Ocean contains around 25,000 different islands, which is more than the total number in the rest of the world’s oceans combined.
9. The Pacific Ocean is surrounded by the Ring of Fire, where there are a large number of active volcanoes.
10. There are more historical artefacts in the ocean than in all of the world’s museum’s combined.

Want to learn more about our oceans and Earth science? For more science, more amazing facts, and more fun, enrol now in our science classes where kids can learn, experiment, explore, and play!