Andrew Wozniak, a chemical oceanographer at the University of Delaware, struggled to handle what his eyes were taking in. Dr. Wozniak was parked at the bottom of the Pacific Ocean under water, near 1.6 miles of Alvin, the potential capacity of the research. As far as he can see there is the almost barren spread of Jet Black Rock.
Just a day ago, this same location was thriving in the swelling waters of the Tika hydrothermal vent about 1,300 miles west of Costa Rica. The creature lives in every inch of the rocky seabed and is dressed in a patchwork of life. The crimson tips of the giant tubeworms intertwine around clusters of mussels and get caught up in what is now. The bug-like crustaceans ran through the scene, while the ghost-like white fish wandered awkwardly for the next kill.
Currently, only one cluster of tubeworms remains in the blackened terrain, all dead. The bright orange lava glow flickered through the rocks, and the fine haze filled the water.
“My brain was trying to understand what was going on,” Dr. Wozniak said. “Where did things go?”
Finally clicked. He and other passengers had witnessed the tail edge of a volcanic eruption on a submarine that buried a thriving ecosystem under fresh lava.
This was the first time scientists have witnessed a clearly active eruption along a ridge in the Central Ocean, a chain of volcanic mountains that stretches around 40,000 miles around the world, like baseball seams. The ridge marks the edges of structural plates when pulled apart, driving volcanic eruptions, creating fresh crust, or layers of Earth living under the ocean. Approximately 80% of Earth's volcanic activity occurs on the seabed, with the majority occurring along the ridges of the Central Sea. Prior to this latest sighting, only two underwater eruptions were caught up in the action, neither of which were along the mid-grown ridge, Oregon State University volcanologist Bill Chadwick said he was not in the research team.
“It's a very exciting first,” he said.
Observing such events provides a unique opportunity for scientists to study one of the most basic processes of our planet: the birth of new seabeds and their dynamic impacts on marine chemistry, ecosystems, microbial life, and more.
“Being there in real time is this absolutely incredible gift. I'm really jealous,” said Deborah Kelly, a marine geologist at the University of Washington, who was not part of the research team.
Dr. Wozniak and his colleagues sailed on the R/V Atlantis ship before departing for Alvin Sub. Their original goal was to study the carbon flowing from TICA vents funded by the National Science Foundation. Hydrothermal holes are like planetary piping systems, which discharge seawater that is heated when penetrated from the seabed. This process helps transport both heat and chemicals from within the Earth, regulate marine chemistry and feed a unique community of deep marine life.
The Tuesday morning diving started like everyone else. Alyssa Wentzel, an undergraduate at the University of Delaware, joined Dr. Wozniak on Alvin, explained the appeal of sinking into the darkness of the depths of the ocean on a 70-minute journey to the seabed. When the light went out, bioluminescent jelly and tiny zooplankton drifted away.
“It was magic,” she said. “It really takes away your words.”
However, as they approached the site, the temperature slowly chopped up, and a dark magic was set as the particles filled the water. The usual dull grey browns on the seabed were covered with tendrils of Inkie rock, glittering in abundant glass. This is the result of rapid quenching when lava hits chilly water.
As the particles clouded the view from Alvin, Woods Hole's marine facility, Caitlynbiadshire, and the pilot, commander of the day's journey, delayed the submarine and kept a close eye on the temperature. So were concerns about the safety of the submarines and crew as they carved. In the end, the pilot called for a retreat.
“It was an incredible sight to see,” they said. “All the life and characteristics I saw just a few days ago have been wiped out. I can't believe I was so lucky to be there within hours of the eruption.”
After returning to the ship, the team learned that a sensitive microphone called the Hydrophone was on board the Atlantis. It was registered as a series of low-frequency booms and campfire-like crackles.
This was the third known eruption at the Tica Vent since its discovery in the 1980s. For decades, Woods Hole marine geologist Dan Fornali and his colleagues have been closely monitoring the site by tracking changes in temperature, water chemistry and more. By combining these analyses with modeling of seafloor diffusion, they noticed that the site appears poised for an eruption and proposed that it will occur either this year or the last.
In 1991, he and his colleagues arrived in Tika within days of the start of the eruption. It could have been still active, he said, but they didn't see a flash of lava to confirm. This time, he said there is no doubt about what Alvin's crew saw. “This was the closest thing we've come to witness the onset of an eruption,” he said.
The team continues to research volcanic activity. Given safety concerns, they are collecting data and taking photos remotely from Atlantis.
This data helps researchers unravel the mystery of deep-sea volcanism and the role it plays in marine ecosystems. “This all has to do with understanding this overall system, the Earth and the ocean,” Dr. Fornali said. “It's both very intertwined and complicated and beautiful.”
