On tsunami forecasts, greenhouse gases from the ocean floor, and living under the sea - Macleans.ca

On tsunami forecasts, greenhouse gases from the ocean floor, and living under the sea

Kate Moran in conversation with Kate Lunau

On tsunami forecasts, greenhouse gases from the ocean floor, and living under the sea
Chad Hipolito

Oceanographer Kate Moran, who advised the Obama administration during the disastrous BP oil spill, was recently named president and CEO of Ocean Networks Canada at the University of Victoria—overseeing a massive underwater observatory that uses fibre-optic cables wired across the ocean floor to deliver a constant stream of data via the Internet. Last year, NEPTUNE Canada made the top-10 list of “humankind’s most ambitious science projects” in Popular Science, alongside the Large Hadron Collider and the International Space Station.

Q: Ocean Networks Canada’s observatory comprises two networks, VENUS and NEPTUNE Canada. How do they differ?

A: VENUS is a coastal cabled observatory with a focus on coastal ecology. It uses sensors to understand various processes. For example, there are concerns about landslides that can break [underwater] cables. Power and communications cables run between the mainland and here—cables are a big deal. VENUS has sensors that would help us predict an underwater landslide. NEPTUNE is the first deep-sea cabled observatory, and it’s really changing the way we do oceanography.

Q: How so?

A: [Oceanography] evolved from the work done during the Second World War, where the U.S. Navy heavily funded understanding the oceans because they had to find enemy submarines and mines. Oceanography exploded and major institutions were set up across the U.S., and Canada was not far behind. It was based on going out on a ship, lowering instruments over one place, and taking one measurement. Because the ocean is moving all the time, reconstructing what is happening is difficult: it took a lot of measurements, a lot of ships, a lot of people observing all different parts of the ocean at different times. The concept of cabled ocean observatories is: let’s put the instruments in the ocean, at one place, 24-7, and we’ll begin to understand that part of the ocean for that entire time period.

Q: What are you finding?

A: VENUS has some fantastic acoustic [data]. With that information, we can begin to understand what’s driving big versus small salmon migrations. Is it El Niño, La Niña or something else? These are huge questions. NEPTUNE spans probably the most diverse ocean environment you can find on the planet. At Folger Passage [off Vancouver Island where one of NEPTUNE’s undersea nodes is installed], there are killer-whale migrations. We were sitting around the office, and somebody yells out, ‘Check out Folger, you can hear a pod of killer whales!’ ”

So you go from that shallow-water environment to deeper sites. At Barkley Canyon [another node site], there’s this white stuff like dry ice. It’s methane hydrate, or methane stored in water molecules in a way that makes it very compact. One cubic metre of gas hydrates on the sea floor is 100 cubic metres of methane when you bring it up to the surface. Some countries, like Korea, Japan and India, are exploring their continental margins for gas hydrate as a resource. I call it a double-edged sword. In the Arctic, recent research suggests methane is coming out of the sea floor and into the atmosphere. It’s a very powerful greenhouse gas.

About 55 million years ago, there was an abrupt climate event. We know the temperature increase over this abrupt change was about 8° C. It caused mass extinction of many species. The estimates are that the rate we’re putting carbon dioxide into the atmosphere today is faster than what happened during the abrupt climate event 55 million years ago. Some suggest the reason this abrupt climate event happened is that the oceans were slowly warming, and all of a sudden you hit this tipping point where they released a whole bunch of gas hydrate into the atmosphere, creating a spike.

That’s the theory. We have a place called Bubbly Gulch at 899 [another NEPTUNE node], where bubbles come out of the sea floor all the time from hydrate below the surface. We’re trying to understand what’s happening. We don’t know if it’s natural at Bubbly Gulch, but we’ll monitor it with time.

Q: What sorts of instruments do you use?

A: We have Wally, a crawler, who lives down there. He’s kind of like minivan size. A scientist in Germany drives him over the Internet. Wally is crawling along a hydrate mound and monitoring changes to the mound. There are actually two Wallys and we always have one down there. [Every so often] you have to bring him up, oil him, change his parts.

Q: You’re studying some very diverse environments, by the sounds of it.

A: They’re all different environments, really different. Endeavour Ridge [about 300 km off the B.C. coast] is one of the most dynamic, where new ocean crust is being formed. There are hot fluids coming out, providing an environment for new life forms. When these [deep sea thermal vents] were first discovered, there was this realization in the scientific community that all life on the planet doesn’t come from the sun. They’re getting their energy from minerals in the ocean, the temperature, all kinds of stuff.

Q: You recently returned from an ocean expedition, monitoring and upgrading the observatory equipment. How did it go?

A: At Barkley, we swapped in a new Wally, and we installed a vertical profiling system—we’re calling it POGO. A buoy carrying instruments crawls 400 m up a cable from the sea floor to the sea surface five times a day, taking measurements all the way up. It will tell us about things like current and temperature, and a lot of the chemistry associated with the water column. At Bubbly Gulch, there weren’t so many bubbles coming out. We went to another place called Bullseye, and the bubbles were coming out like crazy. There was a huge crab field, and they were enjoying the bubbles like a jacuzzi. We were watching these crabs, and one of them lifted up from the sea floor and did a backflip, and landed again. This white material came off its belly. My interpretation is that this gas is coming out, and the crabs are enjoying the bubbles or eating them. Q: You were also installing tsunami sensors off Vancouver Island. A: They’re pressure sensors. They work because, as a wave goes by, there’s more water above the sensors, so they feel the pressure. You have to have a spread of them to characterize the wavelength and direction. Q: What creates a massive tsunami wave? A: There are shallow-water waves and deep-water waves. Deep-water waves don’t feel the bottom of the ocean, but shallow water waves change [shape] because they do. That’s why you get breakers you can surf on. But the thing about tsunami waves, in deep water, they’re [like] shallow-water waves—they feel the bottom. You can imagine a really long wave with tiny wave height. It’s going along the oceans, that little tiny wave, its wavelength is hundreds of kilometres long, and all of a sudden, the space where that little bit of water can go gets really small, and the wave height goes up. That’s why a tsunami wave is so dangerous. I went on one of the first expeditions after the 2004 Indian Ocean tsunami. We tried to find out why that tsunami wave was almost twice as big as what modellers would have predicted. And I did some follow-up work on this island in Thailand. The southern tip of the island had a 20-m [high] wave. The northern tip had a seven-metre wave, and they were only 15 km apart. [The difference in height] was because that same wave that came in was focused, because of the sea floor.

Q. What are some other applications of the technology used for NEPTUNE?

A: We’re going to install a mini-observatory in Cambridge Bay this summer. The Arctic needs to be observed. It’s an experiment in getting the community engaged—we’re going to connect it to a local school, and hopefully get kids excited about science in the North. I’m interested in looking at the role of Ocean Networks Canada more broadly in Canada.

Q: I imagine there are security applications to installing cable in the Arctic, too.

A: Absolutely. The military is totally interested. [The Arctic is] one of our critical areas. It needs to be observed because our northern communities are at risk. Q: How does this compare to the work you did during the BP oil spill? A: I was assigned to do policy [work] on polar and ocean issues, but I have a background in drilling. It just so happened I was able to contribute on that front. We were working [around the clock]; sometimes we’d be down in Houston with BP, sometimes we’d just be meeting in the White House. We had conference calls three times a day. Our role was really to evaluate what was being proposed, to critique it, push back, say yes or no. It was very stressful, because that picture of all the oil going into the Gulf [of Mexico] was on TV, 24-7. So it was embedded in your brain, as you’re doing this. But I thought it was handled extremely well, and I’m not someone who just kowtows to governments. President Obama put into place some really smart, scientifically credible people at high levels before the spill, which allowed decisions to be made based on science, in a way that was remarkable.

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