A team of oceanographers has discovered a huge underwater mountain off the coast of Chile that is higher than the famous Greek Mount Olympus and is home to numerous rare sea creatures.

Researchers from the Schmidt Ocean Institute of California filmed the never-before-seen seamount, which extends 3 km from the floor of the Pacific Ocean toward the surface and is home to a thriving ecosystem, according to the organization.

The unnamed peak lies about 900 miles from South America and was discovered by the team on their 28-day expedition aboard the ship R/V Falkor, which used its under-hull sonar system to map part of the seafloor.

“Sound waves go down and bounce off the surface. We measure the time it takes for them to come back and be measured. From that we get a really good idea (of the topography of the seafloor),” Jyotika Virmani, the institute’s executive director, told CNN.

Virmani noted that to date only about a quarter of the ocean floor has been mapped, even though it covers 71% of the Earth’s surface.

The newly mapped seamount is taller from base to peak than Mount Olympus, which is 2,800 metres high. However, it is shorter than Japan’s Mount Fuji, which is 3,770 metres high.

It is almost four times taller than the world’s tallest building, Khalifa Castle in Dubai, which is 2,723 feet tall.

Scientists estimate that there are at least 100,000 seamounts around the world that are taller than 1,000 meters – or 3,280 feet – and provide a unique and vital habitat for certain marine species.

This recently discovered mountain off the coast of Chile was dotted with sponge gardens and ancient corals.

Using an underwater robot, oceanographers filmed a rare squid of the species Promachoteuthis that lives in the mountain – the first time this animal has been seen alive.

They also came across the ghostly white “Casper Octopus.” This was the first time this eight-legged animal had been spotted in the South Pacific. It has never been caught and therefore does not yet have an official scientific name, Virmani explained.

In addition, two incredibly rare siphonophores of the species Bathyphysa, also known as Flying Spaghetti Monsters due to their thread-like appearance, were sighted.

The latest discoveries were made during the R/V Falkor’s third voyage to the Nazca Ridge, which CNN says could soon become the world’s first protected marine area in deep, international waters under a new United Nations treaty to be adopted in 2023.

“In the three expeditions, we managed to map and explore 25 seamounts, which is a significant number,” she said. “I think we have some good data as a community to present to show that this is a really interesting region for conservation.”

On the three excursions in January and February and the most recent one, the team discovered more than 170 previously unknown species of flora and fauna, the researchers told CNN.

Before this year’s Schmidt Ocean Institute expeditions, it was known that 1,019 species lived in this part of the Pacific Ocean. The number is now over 1,300.

The new species will be included in the Ocean Census, a bold international effort to record previously undiscovered species in the oceans. The goal is to identify 100,000 unknown species within the next decade.