Mountains in the Deep: Exploring the Central Pacific Basin

Reddit in the Central Pacific Basin

By Amy Bowman, Communications and Public Affairs, NOAA Office of Ocean Exploration and Research
May 3, 2017

The Science Team aboard NOAA Ship Okeanos Explorer prepares for the Reddit “Ask Me Anything” (AMA).

The Science Team aboard NOAA Ship Okeanos Explorer (Del, Kasey, Scott, and Mike, from left to right) prepares for the Reddit "Ask Me Anything" session. Image courtesy of the NOAA Office of Ocean Exploration and Research, Mountains in the Deep: Exploring the Central Pacific Basin. Download larger version (jpg, 2.9 MB).

Our science team spent the morning of May 2, 2017, on Reddit hosting an AMA, or "Ask Me Anything " session. They answered questions from the public about our expedition to explore deep waters in the central Pacific – an area of the world where the vast majority of deeper waters remain unseen by human eyes.

There were many great questions to answer and it was an exciting opportunity for the team aboard NOAA Ship Okeanos Explorer to share the Mountains of the Deep: Exploring the Central Pacific Basin expedition with people all over the world.

Several broad topics seemed to top the list for most people, including questions about pollution, hydrothermal vents, technology, sampling, data, and career questions – and there were several "random" questions as well. By far, however, there seemed to be the most interest in the strange and wonderful life beneath the surface. We had multiple questions about the things we have seen and heard in the ocean.

From the minute the AMA opened, our team worked diligently to answer as many questions as possible – responding to nearly eighty in the end! Unfortunately, we could not answer everything in the short timeframe of two hours. However, we had fun trying!

One thing we liked about this platform was that we actually were able to give people some insight into something that we love – ocean exploration. This event also let us interact with many people we had not interacted with before. Doing this AMA really gave us an additional appreciation for how many people are interested in and curious about science in general and ocean exploration in particular. Like many scientists, we want to find additional ways to share science with the public.

While we enjoyed all of the questions, there were some favorites. Each of the scientists wanted to share theirs with you below.

Del Bohnenstiehl

What is the strangest thing you have ever seen or heard underwater?

For "heard," that's got to be the various sounds generated by ice sheets breaking up in Antarctica ( If you want to check out a NOAA Office of Ocean Exploration and Research-funded project to better understand sound in the deep sea, visit:

Scott C. France

In your team's opinion, what is the likelihood that you discover large marine life?

If by "large" you mean physically large, then I believe we will find some large marine life. But it is all relative. On yesterday’s dive, we found "giant" xenophyophores, which are single-celled protists - check out Chris Mah’s blog on these: . But for an organism that is only one cell, giant means 10 to 15 centimeters in size, so perhaps small by your standards. But, I expect we will find corals that are over three meters tall (bamboo corals and Iridogorgia corals, the largest of which are over five meters tall).

On a NOAA Ship Okeanos Explorer expedition in 2015, we discovered the world's largest known sponge ( it was bigger than remotely operated vehicle (ROV) Deep Discoverer, which is itself the size of a minivan!

Mike White

Could you detail the role of a mapping expert in this situation? Forcing a mapping expert to spend days in one spot with a ROV sounds like torture more than research. Or do you cover much more area than I'm picturing, or is this a years long expedition?

Excellent question, so many answers. Our current "Mountains in the Deep" expedition ( is part of a larger three-year project known as the Campaign to Address the Pacific monument Science, Technology, and Ocean NEeds (CAPSTONE; addressing science and technology needs in the Pacific. Some of our cruises during this expedition have been dedicated to mapping. So you are correct – this is a years-long effort.

Concerning our daily operations, our model for ocean exploration is “Always Exploring.” On the ground (really on the seas) this means that when the ROVs are not in the water, we are mapping 24 hours/per day. Our overnight mapping plans include areas in the vicinity that have no mapping data at all. We may even map potential ROV dives sites overnight before choosing the exact dive location in the morning. This, of course, means the Mapping Team staffs NOAA Ship Okeanos Explorer’s control room at all hours, doing mapping 24 hours per day on transits to our next dive site.

One of our newer areas of interest is mapping the water column itself, which is everything between the sea surface and the seafloor. NOAA Ship Okeanos Explorer is equipped with a suite of single beam sonars, sometimes also referred to as split-beam, that we use to map the intensity of sound returns in the water column. This allows us to detect things like concentrations of biomass, gas seeps, and even individual organisms in the water column. Based on suggestions from our partners, we are now keeping the single-beam sonars on during during ROV dives – so even when diving, we are mapping the water column. We even can observe the ROVs transiting through the water column!

And finally, when the ROVs are diving, they typically dive on data generated by the mapping team. Personally, as the Mapping Lead, I am always excited and proud at an interesting find, because it was our mapping data that helped guide us to such an interesting discovery.

Kasey Cantwell

Do you think it's possible to explore 100% of the ocean?

That would take a long time! It’s hard to answer that question, as the ocean is a dynamic environment. Once you’ve mapped the entire seafloor, are you done? Should you work on getting better (higher-resolution) maps? Once there have been photographs of every inch of the seafloor and every organism in the ocean, should you go back and get video so you can understand behavior? Should you look at how an organism interacts with other animals, with its environment? Should you learn about how it grows and develops overtime? Should you research how a community of organisms interacts with each other - or how seafloor communities interacts with those that live in the water column? What physical aspects of of the ocean control or limit the biological communities? A lot of what we know about the deep sea is known from very few observations - there is still so much we don’t know!

A few years ago we had a group of Explorers-in-Training calculate what it would take to map the world using our multibeam system. If you want to see what they came up with, read more about it here:

There are so many questions! Right now we are limited by time on the seafloor, the remoteness of much of our ocean (in terms of depth and distance from shore), and an overall lack of observations for long periods of time. So far, every time we answer one question, three more pop up! This is one of the most exciting parts of science!

So while it is a daunting task, we do our best – join us (LIVE!) as we explore and reveal more of our largely unknown ocean:

If you are interested in seeing our questions and answers, check out the full AMA on Reddit Science .