By Kelly Slivka
About Grant Deane and His Acoustics Glacier Research
Grant Deane listens to the sea. He has spent the past 25 years working as an ocean acoustician at the Scripps Institute of Oceanography’s Marine Physical Laboratory, one of the premier oceanographic institutes in the world. Branching out from their home base in San Diego, Scripps scientists like Deane study everything happening in the world’s oceans—from the impact of Navy sonar on humpback whales to the health of coral reefs to changes in water temperature.
In 2013, Deane and an international team of research colleagues received a grant to record the sounds of glaciers calving and melting into the ocean to learn about climate change and rising sea levels. They traveled to Svalbard, Norway, a rugged archipelago far above the Arctic Circle whose fjords are often covered in a dense white taffeta of glacial ice, and placed hydrophones underwater. Their four months’ worth of recordings provided fascinating results.
When Deane and his colleagues published their project’s findings, their article in Geophysical Research Letters made waves in the national news, capturing the attention of artist Mia Feuer. She contacted Deane and told him she wanted to do a large-scale sculpture using his recordings of the calving sounds. Each calving event would cause a drop of dye to drip onto her sculpture. Deane loved the idea immediately. He sees a deep value in collaboration between scientific and artistic perspectives, feeling scientists owe it to the public to be relatable and relevant. View the Mia Feuer ARTerrain gallery.
“I’m a public servant,” said Deane. “I get paid by taxpayer dollars, and I only get to do what I do because the public, in some sense, believes it’s important.”
In the following interview with Terrain.org, Deane discusses his collaboration with Mia Feuer, his ideas about where science ought to meet the public, and his acoustics research.
Terrain.org: So to get right to it, how did you get hooked up with Mia for her art project?
Grant Deane: Every now and again a paper will attract publicity. And the paper on glacier calving acoustics that Oskar wrote excited some media attention—Oskar Glowacki from the Center for Polar Studies in Poland was the lead author, and I co-authored it with four others. Oskar was interviewed by the BBC, by a German public radio station and by a few newspapers. Over here in the States, I got interviewed by the BBC and NPR. Mia heard the NPR clip and emailed me, proposing this concept of linking real-time sounds in the Arctic to her exhibits. Her idea was so appealing.
One of the things I struggle with is answering people who ask me what sort of science I’m doing. I can tell them, but what kind of experience are they left with? I mean, somebody walks in off the street, right—somebody who’s just driven into work and has dealt with all the traffic, and he’s thinking about how to pay his bills, and some scientist comes on the radio and starts talking about glaciers in the Arctic. And it’s like, But what has that got to do with my life? And now this scientist is saying, “You know, we really need to rethink our carbon usage.” And the guy off the street is thinking, “What does that even mean? Do I even believe it?” And I’m very concerned about that. How do I make this science real for people who live busy, difficult lives in a busy, difficult civilization? If I can’t explain what I’m doing in about three sentences or less to somebody on the street and make it meaningful to him, then should I really be doing it at all? I take these questions really seriously.
So I just instantly identified with Mia’s idea. You’re in an art gallery and you watch a drop of dye fall on a sculpture of a salt relief of the Louisiana marshlands. And what induced that action that you just witnessed is a glacial calving event—to the best we can detect calving events. How visceral and real is that?
Terrain.org: What did you mean “to the best we can detect calving events”? Every drop of dye in Mia’s exhibit won’t necessarily be a calving event?
Grant Deane: Well, right. In full disclosure, it’s not a perfect system, but I actually think that’s part of the artistry of it. Our science is not perfect, either. Our measurement methodologies are not perfect. We have an imperfect vision of the earth, and that imperfection is retained in the sculpture itself, which I also find very appealing.
Likewise, we don’t have a real-time feed of calving events like Mia had originally hoped. It’s expensive and logistically difficult, because we’d have to get a data stream from the Arctic Circle to wherever the exhibit is. And they do have internet access up there, but they have these huge satellite dishes pointed at the horizon trying to reach the satellites, and we’d have to run a kilometer of cable from the station—we’d have to get special permission, and there’s no way we could do it for this exhibit. I don’t even know if we will be able to do it, ever, but we’re going to try. The concept is just so exciting and interesting, and it’s something I have a deep commitment to. We’re both passionate and enthusiastic about this, and I think our enthusiasm and our different perspectives—science and art—found a happy home together.
Terrain.org: You touched on this earlier, but could you expand on what you see as the value of merging those perspectives—science and art?
Grant Deane: I think there’s a huge cultural value. I think a growing number of people are just interested in the earth. They want to know what’s going on. But they want that information relayed to them in a relatable way. And I think lectures, media outlet pieces, newspapers, interviews—it’s all extremely valuable and important. But Mia’s artistic pieces speak to people in a very different way. It hits them deep down. It’s nonverbal. You hear the sound in the room, and you see what’s happening to the artwork, and you get a whole experience, something you can’t simply be told.
And on a personal level, I need something beyond the science that I can be excited and passionate about. I need to connect with other people who feel the same way and have the same passion and excitement. It’s so great to feed off each other and encourage each other, to hear, “Yes, I believe what you’re doing is important and valuable, and it adds to my life.” The energy that comes from that is important.
Of course, I have that in science, but scientists have the same kinds of conversations and the same kinds of approaches. While this, what Mia is doing, is invigorating and fresh and new and interesting, and I love being part of it. So there’s a huge personal benefit to me—and I hope a benefit for Mia and her colleagues in the art world, as well.
Terrain.org: Let’s talk a little bit more about your part in Mia’s project—your research. You said earlier that you feel you should be able to describe what you do to a person off the street in about three sentences. What would those three sentences be?
Grant Deane: If we had just met and you had asked, “What do you do? What are you concerned about?” I would say I’m very concerned about our changing planet, our changing climate, and I’m very concerned about how we’re influencing those changes and what our future looks like, so I go out into the world and I study the things that affect climate and weather. And this particular acoustics project is looking for new ways to study ice in the Arctic Circle—land-based ice, because that’s what causes the sea to rise—because we want to know what our future looks like as that ice is being released into the ocean, and we need new tools, new methods, to study the ice. So I listen to it, I listen to the ice and see if I can turn that sound into information about what’s going on up there. And that’s it. That would be my pitch. Maybe I would try to make it a little more pointed than that, but [laughs]…
Terrain.org: I think that’s pretty pointed! Can we unpack it, though, beyond the three sentences? How did your work on glacial calving acoustics begin?
Grant Deane: In any science career, there’s a progression of the kinds of problems that you look at. To begin, you ask, “What’s within my grasp to solve? What can I do?” And over time, I’ve found the broader questions of what’s happening to our planet, what role we play in it, and what we can do about it have really captured my energy and attention.
So the problem we’re looking at is the 20 feet or so of sea level rise locked up in the Greenland ice sheet. That land-born ice in the Arctic meets the ocean through glaciers, flowing down from the ice cap into the sea.
And the questions are: Are the glaciers’ behaviors changing as the Arctic warms? Are the glaciers melting and retreating more rapidly? How long is it going to take for that ice cap to melt—hundreds of years or thousands of years? What kind of sea level rise can we expect from land-based Arctic ice? About half of all of us live close to the sea, and some countries are really low, like Bangladesh, which is essentially just a big marine delta.
Thinking of this problem, a colleague and mentor of mine at Scripps, Wolf Berger, suggested that we start listening to the sound of the glaciers in the water, and underwater acoustics is something that I do. Wolf and some others organized a meeting about glaciers in Germany, and I went to it and really started thinking about this problem and asking, “What can I do?”
I started working with a colleague in Poland who has been doing polar research for a long time. He also does underwater acoustics and has access to the Polish polar station on Svalbard. He submitted a research proposal and got funded, and five of us went up to make measurements.
Underwater Noise from Acoustic Measurements, Hornsund Fjord, Svalbard, 2013
Click button above to play audio, or click here to download in .mp3 format.
Terrain.org: Why Svalbard?
Grant Deane: Svalbard is interesting because of a cold Arctic current that flows out of the northeast there toward the southwest. It hits the eastern seaboard of Svalbard and curls around the island, separating southwestern Svalbard from warm water flowing from the southwest into the Arctic. The glaciers that we study there are colder than you might expect given their latitude because of the influence of this cold Arctic current, and as a result, those glaciers are an acceptable proxy for glaciers further north around Greenland.
So we had access to the glacier and logistical support, and we were all motivated by this question: Can we study glacier dynamics using underwater sound?
Terrain.org: What’s the advantage of using acoustics to look at glacier calving as opposed to using other measurement methods—like time-lapse photography or seismic devices?
Grant Deane: Well, it’s important to note that we’re looking at calving, but we’re also looking at other processes like ice melting and the outflow of melt water at the base of the glacier, which is difficult to quantify.
But take the specific one that you just mentioned. Why not look at calving with time-lapse photography or other methods? Of course, time-lapse photography is a very powerful and useful study method. However, if you want to monitor 20 glaciers and you have to mount and run a camera for a period of three or four months, photography can be very challenging. These cameras run out of memory, they consume power. Whereas with acoustics, it’s possible to build inexpensive, low-power, long-term recording systems that can be put into the water.
Acoustics are not a panacea, by any means. Photography is valuable and important. And in fact, we need all these other measurement methods going on, too. Otherwise, how are we going to understand or interpret what we’re measuring? So our approach is to measure the heck out of one glacier. We watch the ice melting, we watch the blocks of ice falling into the water, and we relate it to what we hear underwater. Then we’ll understand the production of the sound. Great. That’s the first problem we have to solve. Once we’ve done that, we can study the sounds until we understand the link between the sounds and physics, and then we can use the sound to monitor the physics. And then, we can argue, we won’t need all these other measurement methods. We can just use the sound. That’s our hope.
Terrain.org: Is that where you are right now? Is the data that you have, that Mia is using, collected with the hopes of determining a systematic approach for measurement by overlaying all these different methods?
Grant Deane: That’s exactly right. We had time-lapse camera measurements that went with our acoustic data, for example, so we saw all the blocks of ice falling, we knew it was a calving event. Then Oskar was able to estimate the size of the blocks and the height that they fell from. All of that was part of the study.
Terrain.org: Could you tell me more about how you made your recordings?
Grant Deane: We had two main measurement methodologies. One was the deployment of a hydrophone from a boat, and those recordings were limited to a period of a few hours. The other was an underwater recording system mounted on the seafloor, on the bottom of the fjord.
I helped deploy our first system—I went up to Svalbard and went diving in the glacial fjord, down to the bottom of the bay, and deployed these recording systems. The first one was destroyed by an iceberg, but the second was successful. We deployed it for about eight months, but the batteries failed after four months. So we got a total of four months of data.
Terrain.org: Wow, so you went diving in the Arctic? How exactly did you deploy the acoustic system? What does it look like? How did you get it back?
Grant Deane: The system itself is in a cylindrical metal canister attached to a heavy metal track—to keep this thing on the bottom. The track weighed maybe 100 to 150 pounds. Essentially, the whole system gets pushed over the side of a boat, and to recover it, we go down and attach floatation to raise the whole thing. We don’t leave anything in the bay. Everything that’s deployed is recovered.
Terrain.org: How deep were the systems set?
Grant Deane: We dove at about 70 to 80 feet.
Terrain.org: Was it dark down there?
Grant Deane: Yes, the water’s pretty murky because of the sediment outflowing from the glacier. There’s a lot of plankton growing as well. In the top layers it’s light but murky, yet very quickly the light is attenuated. So by the time you get down to the bottom, it’s dark, and if you stir up sediment from the sea floor, it gets very, very dark [laughs].
Terrain.org: I bet! So can you tell me what you learned from this acoustic data set you retrieved? Anything new and exciting?
Grant Deane: There were three main results that came from these studies. One was that the intensity of sound measured during a calving event can be related to the size of the block of ice that falls in the water, the height that it falls from, and the type of calving event.
It turns out that there are three different calving modes. Ice can fall straight down, ice can slip down the glacial face, or ice can break off from the bottom of the glacier and float up toward the surface. Each of those calving modes has a different acoustic signature, which was very interesting because it means that you can distinguish the calving mode from the sound that it makes—which is important for understanding calving dynamics.
Our second main area of study was the underwater soundscape. Imagine you’re at a cocktail party, and there are two or three groups surrounding you. You close your eyes, and you can hear sound coming from this direction, from that direction. Then somebody drops a wine glass, and you hear a crash, and you know it was directly in front of you. Somebody shuts a door and you know it was behind you. What you’re doing is differentiating acoustic events into categories and directions. We wanted to see if we could do the same thing with the underwater soundscape in the glacial bay. And we found, yes, we can do that. There is this rich underwater soundscape waiting for us to study and interpret.
Our third main result had to do with specific mechanisms for the way sound is generated. Bubbles exploding out of little blocks of ice, making sounds, that sort of thing.
Terrain.org: What are the implications of these findings?
Grant Deane: So far, we’ve posed the questions: Can we exploit these sounds to study ice melting? Can we exploit the sounds to study calving? And so far, the answer is yes. Of course, we may get stuck here [laughs], but as I said, this study is the first step in convincing our colleagues that we can do something interesting and valuable with underwater sound.
Terrain.org: So eventually this sort of acoustic measurement could be used to discover the rate and habits of glacial melting, and then that can lead to more information about sea level rise and the effects of climate change?
Grant Deane: Yes. How quickly are the glaciers destabilizing? The glaciers advance and retreat, advance and retreat, on an annual basis, but they always retreat further than they advance, so there tends to be a net loss year by year. Is that net loss constant, is it accelerating, how is it related to weather, how is it related to water temperature, how is it related to latitude, how is it related to the structure of the ice itself? Can we understand these factors? Can we contribute to the ongoing conversation about glaciers and sea level rise in a meaningful way?
Terrain.org: Are there any last things you’d like to say about this project, about your research?
Grant Deane: If there was a request I could make of people, it would be that they try and find out for themselves, in their own way, what’s going on in the world. Read, get on the internet, talk to people, go to art exhibits, talk to scientists, and then make up your own mind. Why are people saying what they’re saying? Do they have a vested interest or not? Are they authorities on the subject? Is this subject their life or is it something they have an opinion about?
Even people who don’t want to see that things are changing must be able to see things are changing. Weather patterns are changing, precipitation patterns are changing, disease vectors are moving around, ice is melting—look. The whole planet’s changing, and it’s terrifying.
And of course, terrified people get angry—if they’re powerless. If you’re terrified and empowered—great. Now you’re motivated to do something. But if you’re afraid and powerless, and no solutions are being given to you, you’re angry. So I think there’s anger about climate change, and I think part of that is fear. We don’t know what the future looks like, and we don’t know what to do about it. So one of my answers is to study it. Angry people who go out and look for information for themselves are more likely to be rational and calm and to seek solutions, I think. And that’s why public outreach is so important—it helps people get informed through good sources of information.
Of course, I would claim that I’m an honest source of information, but there are lots of sources of information out there. This interview will be one. And so is Mia’s artwork.
Header photo of glacier where it enters the sea on Svarlbad courtesy Shutterstock.