Data is flowing from an ocean-bottom observatory off the Pacific Northwest coast that was the brainchild of a UW oceanographer, and the first results are explosive.
Sandie Doughton
Seattle Times Science Reporter
The idea was hatched in a bar more than two decades ago.
University of Washington oceanographer John Delaney and a colleague were nursing cocktails and venting their frustration with the traditional approach to studying the underwater world.
The ocean and seafloor are dynamic environments, with tectonic plates pulling apart, superhot fluids gushing from hydrothermal vents and an ever-shifting cast of creatures on the move. But scientists could only catch glimpses of what was going on under the surface during brief, costly research cruises.
When his friend mentioned a new technology called fiber optics, it fired Delaney’s imagination. He grabbed a napkin and sketched out a attached to cables that could transmit data instantly and continuously. He called it an underwater observatory.
After 25 years of pitching the idea to anyone who would listen and scrounging for money, Delaney is finally seeing that vision realized. And the scientific payoffs started with a bang that even he couldn’t have anticipated.
With the completion this month of a data portal, information and images from a suite of 140 instruments off the Northwest coast are finally flowing to scientists around the world. Even before the data were widely disseminated, the observatory allowed researchers to track, for the first time, the eruption of an underwater volcano as it happened.
“That was incredibly exciting,” Delaney said. “This signals a new era in ocean science, where the cable allows us to actually be there 24/7, 365 days a year.”
Eruption under way
The eruption provided a serendipitous showcase for the observatory’s power to capture events that scientists had previously been able to examine only after the fact.
In April 2015, just months after a team from the UW and other institutions installed the final instruments on the $200 million cabled network and powered it up, the new seismometers detected an uptick in rumblings under a submarine volcano called Axial Seamount. Located 300 miles off the Oregon coast and covered by nearly a mile of water, the sprawling volcano straddles a ridge where the seafloor splits and new crust is born as molten rock rises from the depths.
Scientists were glued to their computer terminals, watching the shaking build to a crescendo. In one 24-hour-period, the instruments recorded more than 8,000 small quakes as magma muscled its way upward.
Then the earthquakes dropped off abruptly, as if someone had thrown a switch. At the same time, pressure sensors revealed that the seamount — which had been swelling for several years — deflated like a balloon.
That’s exactly what you would expect to see from a volcano that just ejected massive amounts of lava — but scientistsweren't sure at first where the molten rock had gone.
Then they looked more closely at the seismic data and saw bursts of small earthquakes from an unexpected location on the volcano’s northern flank. Hydrophones also picked up the sound of explosions in the area, probably generated when pressurized gas burst from the lava, said UW marine geophysicist William Wilcock.
A few months later, when a research crew visited the site by ship, Wilcock and his colleagues relied on the observations from the cabled observatory to tell them exactly where to look for freshly erupted rock.
“It was pretty neat,” Wilcock said. “They went there and found this very thick lava flow.”
A remotely operated vehicle lowered from the ship recorded stunning video of formations called pillow basalts created as magma erupts into water, said UW oceanographer Deborah Kelley expedition
Hot fluid still gushed from openings in the new seafloor. Vents called snowblowers spewed blizzards of white minerals encrusted with microbes. Mats of microscopic organisms were already beginning to colonize the newly erupted basalt.
And none of the instruments were damaged.
“We were phenomenally lucky,” Kelley said. “We got a nice eruption and it didn’t take out our array.”
Now that all the data are available, Kelley is eager to see whether the eruption generated a “megaplume” of superheated water and chemicals similar to the ash clouds that rise from volcanoes on land.
In addition to seismometers and pressure gauges, the observatory includes instruments that measure ground tilt, water temperature, oxygen levels and chemical composition. Other sensors can collect microbes and analyze their DNA. A few instruments were designed to zip up and down on vertical cables, collecting samples at different depths.
Kelley also hopes to explore the links between underwater earthquakes and eruptions and the microbes that thrive in the harsh environment — and may represent the origins of life on Earth and models for possible life on other planets.
“The idea is that this array will be in place for at least 25 years,” she said. “There are so many questions we can address.”
Dream come true
Live video from a high-definition camera on the seafloor is also streaming online now. It’s not continuous yet, but Delaney couldn’t wait to share it with his students.
“I’ve been dreaming about that for more than 20 years,” he said in his office last week, as he gazed at an image of a 13-foot-tall hydrothermal vent called a black smoker, with scalding water flowing from its top and a thick blanket of palm worms, filamentous bacteria and limpets clinging to its sides.
“What you’re looking at is what’s happening on the bottom of the ocean, 400 kilometers away — right this second,” he said, shaking his head as if he couldn’t quite believe it himself.
When Delaney proposed the underwater observatory, many scientists dismissed it as impossibly ambitious — and impossible to pull off. Others worried it would gobble up too much of the slim budget allotted to oceanographic research.
Colleagues use the word “visionary” to describe Delaney’s view of the future of oceanography and his passion for the observatory project. But it also took a lot of time shuttling back and forth between Seattle and Washington, D.C., along with nitty-gritty negotiation to build support, secure funding and orchestrate the installation, said marine geologist Daniel Fornari, of Woods Hole Oceanographic Institution.
“John is a very determined man,” Fornari said. “He lived and breathed this for two decades.”
Delaney is also eloquent in describing humanity’s connection to and reliance on the oceans, said marine scientist Maya Tolstoy, of Lamont-Doherty Earth Observatory at Columbia University. A section of Delaney’s website is devoted to Pablo Neruda and other poets who explore the mysteries of the sea and human soul.
“I would describe John as the poet laureate of the seafloor,” Tolstoy said.
After multiple delays and reductions in scope, the National Science Foundation funded the array as part of its broader Ocean Observatories Initiative.
The fiber-optic infrastructure and the scientific instruments were all in place by the end of 2014. But scientists around the world were forced to wait more than a year for completion of the data portal.
The bugs that remain in the data-delivery system aren’t enough to dim Delaney’s exhilaration at seeing the observatory begin to function as it was meant to.
And at the age of 74, he’s already looking ahead.
The existing instruments are too far offshore to closely monitor the submarine fault called the Cascadia Subduction Zone, which can unleash monster earthquakesand tsunamis. So Delaney is pushing to add a dedicated network of seismometers and pressure gauges.
He’s also enthusiastic about new, autonomous gliders and other mobile platforms capable of performing experiments and exploring the expanses between fixed instruments.
“We’re still at the very early stage with the cable,” he said. “We’re planting the seeds for the next generation of oceanography.”
