by Julia Thiel
Like many of the people profiled in this week's issue, Janet Voight is fascinating—so much so that even though I knew the interview I did with her would be cut down to just a few hundred words, I couldn't bring myself to keep it to less than an hour. And even though I knew that space limitations didn't exactly allow for an 8,000-word interview in print, seeing it cut down was painful. Fortunately, for all that extra wordage, there's the Internet. Below are details about the bottom of the ocean that didn't make it to print, as well as the video from the Field Museum that made me want to talk to Voight in the first place, in which you can see the octopus feeding behavior that she describes in the interview.
On diving in the Alvin, one of the few manned submersibles in the world:
When you dive in Alvin you get in at eight in the morning and it's a seven-foot diameter sphere. And I'm six feet tall and it seems that anybody I've ever dived with was about six feet tall. And if everything goes well you don't get out of the sphere until 5 PM that evening. There's not a lot of primary creature comforts, although they'll make you a sandwich and give you a candy bar. And it's cold. It is so cold because it's a metal sphere. After you get below 1,200 meters or so, the sea water is two degrees Celsius. If you put a metal sphere into two-degree water it just takes the heat out. And as you're in there, even during descent, the water vapor in your breath starts to condense on the inside of the Alvin, on the windows, so you get little streams of water running down the windows, and it's a little disconcerting the first time. By the end of the dive it's just, like, soggy because you've got three people's breath in two degrees—it's like being in a refrigerator.
Alvin has mechanical arms that are powered by hydraulics and you can tell the pilot, pick that up for me and put it over there, and he should be able to do it. If they're really good they can do things like pick up teacups from where the Titanic went down.
When Voight goes on deep-sea dives, she's generally looking for what she refers to as chimneys, which is where you're most likely to find life at 6,000 feet deep. Here, she describes what those are:
[Chimneys] are cold hydrothermal vents. Where hydrothermal vents are, you basically have hot rock under the surface of the ocean's floor, and of course the rock heats the water. As the water heats, it rises and that draws in colder water and some of that water penetrates the surface of the crust. As it moves through the crust of the earth's surface, it's chemically altered. Oxygen is driven off and it's reduced from sulfate to sulfite and ferrous to ferric. It undergoes a redox reaction. So it's all reduced and also it leaches metals out of the basalt and when it comes out it's hot and chemically reduced. It may have picked up so many metals that it's supersaturated, like if you've ever made sugar candy and you heat it and dissolve the sugar and as soon as you cool it the sugar comes out. Well, that's the same thing that happens with this water, only the metals precipitate out. And if you have a nice fluid conduit where the fluid flow always comes out of this big pipe, you have a lot of metal build-up, and it forms a chimney. It looks like a chimney because the metal precipitating from the fluid looks like smoke, and it gets taller and taller until it falls over. Sometimes something happens to the fluid flow, and then it's not hot anymore, so it's this vertical thing and filter feeders tend to live on it—you know, animals that strain stuff from the plankton.
It's conspicuous life that develops around the vents. There's a whole lot of it and all the animals that are associated with the vents rely on the bacteria that uses the chemicals from within the hydrothermal fluids. That is something that before hydrothermal vents were discovered, nobody would have believed possible because we were taught all life on earth depends on the sun, but in hydrothermal vents there's no influence of photosynthesis.
Voight also has the distinction of having had seven species and six phyla named after her. "When you name a species you can give it a descriptive name or you can name it after anybody but yourself," she said. "Typically they're specimens I collected that are undescribed species that we made available to a specialist. So they chose to name it after me. And that's so nice."