A cross section map of Challenger Deep, the deepest point on planet Earth.
John Nelson/Esri
From NPR by Regina G. Barber, Berly McCoy, Rebecca Ramirez
Life at the bottom of the ocean is extreme.
It's pitch black, the temperature hovers right above freezing and the pressure is immense.
Although many species have evolved to survive and thrive at these depths, the seafloor is very much uninhabitable to humans.
Although many species have evolved to survive and thrive at these depths, the seafloor is very much uninhabitable to humans.
In fact, only around a couple dozen people have actually been to the deepest part of the ocean floor, a place known as Challenger Deep.
A regular Styrofoam cup (L) next to a Styrofoam cup that traveled to Challenger Deep and back (R). Dawn Wright
Marine geographer Dawn Wright is one of those people.
"It's a place that can either be horrifying and terrifying or it can be fascinating and infinitely beautiful. And for me, it was the latter."
Wright is the chief scientist of the Environmental Systems Research Institute.
Wright is the chief scientist of the Environmental Systems Research Institute.
She is also part of a global race to map the entirety of the world's ocean by 2030, which experts say is essential not just for pure scientific knowledge, but human safety and technological advancement.
Challenge accepted
When Wright dropped into Challenger Deep, it was exciting — and purpose-filled.
As a marine geographer, she is interested in the "rocks and the motion at the bottom of the ocean."
Challenger Deep is in the Pacific Ocean inside of the Marina Trench. It's just shy of 11,000 meters, or 6.7 miles, below the ocean surface.
Challenger Deep is in the Pacific Ocean inside of the Marina Trench. It's just shy of 11,000 meters, or 6.7 miles, below the ocean surface.
In July 2022, Wright and pilot and ocean explorer Victor Vescovo descended in a small submersible, then called the Limiting Factor.
Wright likens the experience to being in a space capsule.
Wright likens the experience to being in a space capsule.
"You're in a very small space. You're surrounded by instrumentation," she says.
"We had a whole series of oxygen tanks above us because we had 96 hours of oxygen, extra oxygen that we took along in case of emergency."
Dawn Wright (L) and Victor Vescovo (R) descend in a submersible to Challenger Deep, the deepest part of the ocean. Caladan Oceanic
Once the pair descended about 800 meters, they lost sunlight.
"And it remains that way all the way down to the very bottom," says Wright.
For her, that darkness made the fireworks show they were about to see that much more amazing.
Worms, jellyfish, anglerfish — "These species that are able to create their own light through bioluminescence," she says.
Worms, jellyfish, anglerfish — "These species that are able to create their own light through bioluminescence," she says.
They use the light to find mates, hunt and — apparently — attempt to communicate with submersibles.
"Victor noticed flashes of light as we reached that zone in the ocean.
And then he started flashing the lights of the submersible at them. And we saw them flash back."
Delights of deep sea marine creatures aside, Wright and Vescovo were focused on testing a special mapping device.
Delights of deep sea marine creatures aside, Wright and Vescovo were focused on testing a special mapping device.
Mapping the seafloor
If so few people make it to the bottom of the ocean, why do we need to map it? It's less for road trips and more for, well, a lot of other things.
One of the most important: monitoring and predicting tsunamis.
That's because most tsunamis are a result of earthquakes on the seafloor.
That's because most tsunamis are a result of earthquakes on the seafloor.
Wright explains that "when you have that disruption on the ocean floor, the water above the ocean floor gets severely disrupted as well," which can generate large waves that can turn into tsunamis.
That could give coastal areas more warning time in the event of a tsunami.
The bottom of the ocean also serves as an important site for human innovations.
The bottom of the ocean also serves as an important site for human innovations.
For example, submarine cables stretching between continents account for the vast majority of our internet traffic.
Also, offshore wind farm developers need to know the composition of the seafloor to anchor turbines.
Mapping the ocean floor may also help protect vulnerable marine habitat, or aid in finding people and objects lost at sea.
Historically, satellite data has been key to mapping the ocean, but Wright says these maps are too blurry to see fine details.
Mapping the ocean floor may also help protect vulnerable marine habitat, or aid in finding people and objects lost at sea.
Historically, satellite data has been key to mapping the ocean, but Wright says these maps are too blurry to see fine details.
Credit: NPR
The solution?
Sound navigation and ranging, or sonar.
"It's like when you get a new eyeglass prescription," she says.
"It's like when you get a new eyeglass prescription," she says.
"Everything comes into focus, and you're seeing things clearly."
The basic principal for sonar mapping is a ship or instrument sends pulses of sound from the ocean surface down toward the seafloor and waits for it to come back up.
The basic principal for sonar mapping is a ship or instrument sends pulses of sound from the ocean surface down toward the seafloor and waits for it to come back up.
Based on the amount of time it takes for the sound to return and factors like temperature and salt content, scientists can get a specific depth.
Scanning a whole area of the seafloor, then, will give you a depth — or bathymetry — map.
In the same way that a topography map shows elevation changes, a bathymetry map shows changes in depth.
Seabed 2030
Only about 25 percent of the world's seafloor is currently mapped in detail, but an initiative called Seabed 2030 aims to get to 100 percent in just over six years.
The task, led by the Nippon Foundation and GEBCO, may seem daunting, but Wright says that just a few years ago, only around 6 percent of the ocean floor was mapped.
To complete the picture, ocean mappers are looking to industry to fill in some of the gaps.
To complete the picture, ocean mappers are looking to industry to fill in some of the gaps.
"The hope is that we can very quickly get to 40 percent if we can get a lot of these companies to release their data and to make it public," says Wright.
If the entire ocean floor isn't mapped by 2030 — one of many goals of the United Nations' Decade of Ocean Science for Sustainable Development — Wright says the work will continue.
If the entire ocean floor isn't mapped by 2030 — one of many goals of the United Nations' Decade of Ocean Science for Sustainable Development — Wright says the work will continue.
But, she adds, "The longer that it takes us to get too close to 100 percent, for all the reasons that we've talked about, we are just going to be playing with fire, so to speak."
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