Oceans cover 71% of the Earth's surface, and there's a lot we don't get to see — from vast mountain ranges to ancient land bridges that humans used during the Ice Age.

This NASA video highlights these fascinating features as it reveals what our planet would look like if the oceans drained away.

The original video was released in 2008. However, planetary scientist James O'Donoghue recently remade it to highlight new discoveries, slow down the animation, and add a water tracker as the draining occurs.

O'Donoghue works at the Japanese space agency, JAXA, but he used to work at NASA.

"I like how this animation reveals that the ocean floor is just as variable and interesting in its geology as the continents," O'Donoghue told Business Insider. He added that emptying the seas reveals "not only the ocean bottom, but also the ancient story of humanity."

In the video, you can see the continental shelves emerge first. This is where land bridges existed tens of thousands of years ago, allowing humans to travel between continents.

As sea levels drop below 3,000 meters, the video unveils the mid-ocean ridge, which is be Earth's longest chain of mountains at 37,000 miles long. Finally, the deepest drained depths reveal the Mariana Trench.

A drained ocean would obviously be disastrous for the human race, but it's tantalizing to think about all that exists beneath the surface.

Ben Bolton looks at everything through a video lens.

What Earth would look like without oceans
A re-edited NASA simulation shows what Earth would look like if our oceans drained away.