Scientists are back from a 36-day mapping expedition in the remote Northwestern Hawaiian Islands.
Researchers say it's the best data they have ever collected of the fully protected marine conservation.
Click here to watch Nana Ohkawa's report.
It's the largest protected area in the United States -- bigger than all our national parks combined -- and what's in The Papahanaumokuakea Marine National Monument is still mostly a mystery.
After all, 98 percent of it is more than 100 meters deep.
Scientists are back from their latest mapping expedition using the Schmidt Ocean Institute's sonar system. They brought back new discoveries and new knowledge from the bottom of the sea.
"This is such a large area that NOAA and others are trying to protect it both for the environment and Hawaiian culture. In order to do that, we need to know first of all what really is there," said Colleen Peters with Schmidt Ocean Institute.
Now an additional 17 percent of the area is mapped. Only 50 percent was mapped before this expedition, leaving the scientists with little to no data to go on.
With the new data, they are getting a better understanding not only of what previously unknown species live in the waters but also more on how the Hawaiian Islands were formed.
"We found volcanoes that were too old to have been created in Hawaii, which means that they already existed on the sea floor. They came from the East Pacific and were brought over here as the plate moved into the Central Pacific," said chief scientist Christopher Kelley.
The scientists believe the Hawaiian islands formed in and around those sea mounts, some date back 90 million years.
Filling data gaps will help facilitate future research and discoveries.
"When you want to deploy submersibles, divers -- anything that costs a lot of money -- you really want to target places where you think you are going to find interesting things," said Daniel Wagner, a research specialist with PMNM.
The research team publish mapping data. Maps will be added to Google Earth for everyone to check out.
The next expedition will take off on May 2.