The deep blue is still unchartered territory for humans: Less than 5% of oceans have been explored. Earth's oceans are also home to countless species, a considerable portion of which we have only discovered in recent years and still loads more yet to be unveiled. Full of mysteries, these bodies of water are showing us they are the ultimate source of life for our planet – after all about 3/4 of the planet's surface is covered in water. Here are 10 interesting facts that will make you appreciate oceans more:

1. Rock bottom

The deepest part of the ocean is called Challenger Deep, and it is within the Mariana Trench, which is said to have a depth of around 36,000 feet, lying about a few hundred miles to the southwest of Guam.

2. Waterfalls underwater?

The Denmark Strait cataract, Earth's highest underwater waterfall, can be found in the Atlantic Ocean and has an 11,500-foot (3,505-meter) drop.

3. Extreme points of Earth

Point Nemo in the Pacific Ocean is the textbook definition of quite literally the middle of nowhere, surrounded by over 1,000 miles (1,600 kilometers) of water in all directions. To be exact, it is called “the oceanic pole of inaccessibility" or the farthest point from any land on Earth.

4. Swallowed treasure

Sink me! Over $60 billion in sunken treasure is said to still be in oceans around the world. Oh, and the number of historic artifacts under the sea easily surpass those in all of the world's museums.

5. Ocean graveyard

There are literal "dead zones" that cannot sustain any sea life in oceans and large lakes around the world. These zones, most of which were naturally occurring but some are now manmade, are hypoxic (meaning low in oxygen) and cause these bodies of water to fail to support the marine life living there.

6. Source of oxygen

We always acknowledge the power of trees, but what about those plants underwater? Some 70% of the oxygen we breathe actually comes from marine plants in the oceans.

7. That marine blue

From deep blues to vibrant turquoises, the seas of the world get their blue tint because of orange and red wavelengths from the sun.

8. Rubber duckies

You may have thought that rubber duckies were best preserved for long, bubbly baths, but oceanographers have actually used these funny-looking plastic animals to get a better understanding of water currents.

9. Life runs deep ... underground

The ocean's floor contains important cables from multinational communications companies that allow the internet to travel across the globe.

10. Aquatic volcanoes

Many of us know Mount Stromboli in Italy or the world's most active volcanic mass Kilauea in Hawaii. But around 80% of volcanic eruptions actually occur underwater.