From Alvin to Robots: Deep Changes in Ocean Science
Topics: Biology, Engineering, News, Radio
- Copy and Paste to Embed
Later this year, an iconic instrument of science returns to the sea: Alvin, the submersible that captured the first images of the Titanic wreck and discovered countless new species in exotic places like hydrothermal vents at the bottom of the ocean floor.
Ocean technology has come a long way since Alvin made its first dive in 1964. Increasingly, scientists rely on robots, rather than manned submarines such as Alvin, to explore the ocean.
But when humans no longer put themselves at risk in the ocean depths, do we lose the thrill of exploration?
The thrill, and the danger, of ocean exploration
It was 1991, Bob Vrijenhoek and another ocean researcher, Richard Lutz, were leading an expedition off the coast of Oregon.
It was the last dive of the trip, and the stakes were high. In order to justify the steep expense of an Alvin expedition – some $30,000 a day — they needed more samples.
Graphic by C.K. Hickey; photo by Woods Hole Oceanographic Institution.
Cindy Van Dover, herself an ocean scientist who today leads Duke University’s Marine Laboratory, was Alvin's pilot that day. “We were looking for what we call seeps on the sea floor, places where we have these really dense populations of invertebrates.”
But in the search for clams, Alvin had been steadily skimming up mud from the ocean surface, 500 pounds of it.
The scientists decided to head to a different spot. But when Van Dover pulled the thrusters to leave the floor, nothing happened.
"We are not moving."
No one knew what was wrong. Alvin’s portholes face outward, not down, so there was no way of seeing all the mud on the bottom of the vessel.
Recalls Vrijenhoek, todaya senior scientist at the Monterey Bay Aquarium Research Institute. “they had no idea whether the sub was stuck in an old fisherman’s drift net, whether it was hung up on a cable? Or maybe a giant squid?”
Van Dover radioed up to the ship.
“You know, here’s the situation,” she recalls saying, “I’m on the sea floor, I can’t get up off the bottom. I’ve tried the thrusters, I’ve dumped ballast water."
If all else failed, Van Dover and the others knew they had one last option. Alvin’s titanium sphere, which holds the passengers and life-support systems, is attached to the rest of the sub with a single screw. With the turn of a key, Van Dover could unbolt the screw, releasing the sphere – “like a ping pong ball,” as Vrijenhoek says – to float up to the surface.
No one had ever done this before.
In consultation with the technicians on the ship above, Van Dover began dumping steel weights. Over the course of about an hour, 600 pounds of weights fell to the ocean floor.
Alvin started to lift, dragging 500 pounds of useless mud.
Graphic by C.K. Hickey; illustration by Woods Hole Oceanographic Institution.
The romance of being there
Van Dover says she always knew they’d be ok. But this is one of those old science yarns that gets repeated over and over. It seems to sum up the adventure and the risk that deep ocean science is all about.
“Of course, you’re cold and shivering and you haven’t gone to the bathroom in eight hours,” says Vrijenhoek, “but the experience is incredible. You’re sitting there with two miles of water above your head. It’s dangerous, romantic, it’s an adventure, it’s exciting. And I think the lure of it is what drew many of us into this and kept us there for years. It’s just an exciting thing to do.”
But this experience is increasingly rare. It’s a lot like what’s happened in space exploration: fewer astronauts, more machines.
Twenty years ago, Alvin was one of a small fleet of subs available to scientists. Several have been retired or sold. Two others, owned by the University of Hawaii, are being threatened by budget cuts.
Increasingly, robots, not people, are exploring ocean depths.
Graphic by C.K. Hickey; illustration by Woods Hole Oceanographic Institution.
Meet the robots
At a warehouse in Alameda, California, Meghan Donohue, a technician for Scripps Institution of Oceanography, in San Diego, shows off a brand new remote operated vehicle, or ROV. It’s a robot, a little bigger than a refrigerator.
A 12-hour dive with the new ROV costs about a tenth of Alvin’s price. That’s because scientists don’t go underwater. They stay up above the waves in a converted 30-foot shipping container that can be lifted with a forklift onto the ship.
Inside the container, two office chairs face a wall of computer monitors. Joysticks control the robots movements, as well as a mechanical arm that can be used to pick up samples.
On a calm day, you might forget you’re on a boat. It feels like the windowless office of a used car lot.
Is the thrill gone?
Now, to a lot of people, this might sound like a bit of a let down. Instead of looking through a porthole, you’re looking at it through computer monitor.
But to Bruce Appelgate, a researcher at Scripps and head of its ship program, it’s obvious: ROVs are just better.
“We can return much more data, better observations, give more people opportunities than you can with a submersible. It’s really a no brainer,” he says.
Faster, Cheaper, Safer
ROV work is vastly less expensive than booking a trip on Alvin. Because ROVs are tethered to the ship, they're less reliant on battery power, and can stay down for 12-hour stretches, or longer.
At MBARI, in Moss Landing, California, two large-scale scientific ROVs have been exploring ocean depths and making discoveries for years. One of them, the ROV Ventana, has completed more dives than any ROV in the world: 3,600 dives since its purchase in 1989.
Scientists, both at MBARI and other research centers, cite the benefit of collaboration that ROV work allows. Freed from the space limitations of a tiny submersible, an ROV research team might include half a dozen scientists — for example, a biologist, geologist and chemist, all looking at the same site through the ROVs monitors.
And an ROV’s high-definition cameras allow for better observations.
“On the Alvin, you're limited to just a few degrees out of a small porthole,” says Appelgate. “Compare that with an HD video broadcast that you can pan and zoom. It's night and day.”
But what about the romance?
“I get wistful thinking about the days when I used to sniff mimeographs in third grade,” he says, laughing. “Well we don't use that technology anymore, either.”
Of course science is more than technology. It has to be inspiring. Kids need to get excited about exploration, so that they’ll grow up and do more science.
"Just look at James Cameron."
Cindy Van Dover wonders if robots can really have that effect. Look, she says, at filmmaker James Cameron, who made a much-publicized dive to the deepest part of the ocean back in March.
After all, she says, robots had already made that dive. Outside of the scientific community, few people noticed.
“Why was everyone so excited about Cameron being the third person to get to the bottom of the Challenger Deep? It’s that he was there.”
Another concern is funding. Without popular excitement, it’s harder for scientists to get grants for their work.
“Humans are meant to adventure and explore," says Vrijenhoek, "and if we just do this with machines, well, that's fine, science progresses well and happily. But once you put human beings in the picture, then the popular opinion and popular support for it changes.”
Scientists do still have Alvin. In fact, in December, the sub returns from a two-year upgrade. Built in 1964 to withstand depths of eight thousand feet, the new and improved Alvin will soon be able to sink 21 thousand feet – that’s four miles beneath the ocean surface.
In the future, robots may be making most of the dives. But a lucky few scientists will go deeper than ever before.
Tags: Alvin, appelgate, cindy van dover, MBARI, Oceanography, ROV, scripps, vrijenjoek