Researchers with Sandia National Laboratories are using a fiber optic cable at the bottom of the Arctic seafloor to study permafrost – which they say gives us a better understanding of global warming patterns.
KUNM sat down with scientists Christian Stanciu and Jennifer Frederick to talk about how it works.
JENNIFER FREDERICK: We are investigating the Arctic sea floor, because it contains permafrost, and how that evolves in the Arctic influences the rest of the globe. The Arctic is one of the most dynamically changing environments. It's warming much quicker than the rest of the globe. So, studying what happens there tells us a lot... Not only about changes we expect in the Arctic, but also the rest of the world due to global warming.
KUNM: I'm sure there's an end goal. What questions are you trying to answer?
CHRISTIAN STANCIU: The project has two components. One is distributed acoustic sensing, and one is distributed temperature sensing. I work on the acoustic sensing and Jennifer is working on the temperature sensing part.
KUNM: I'm assuming the acoustic approach is about finding patches of ice, the seismic structure of the Arctic floor... What's the purpose of that?
STANCIU: Yes, so distributed acoustic sensing is an emerging technology and we are using light in telecommunication optic fiber. We're sending a light pulse into the fiber and we're measuring the response of the fiber as that energy travels through. This technology is primarily sensitive to vibrations. So, when I say vibrations, think of earthquakes... You can record the vessels moving around, even whales. And the end goal is to be able to characterize the near shore subsurface structure, i.e., the permafrost structure.
KUNM: I've heard this "permafrost" you're talking about compared to a leftover roast turkey sitting in the back of the freezer since Thanksgiving. What is so special about Arctic permafrost? Can you define what that is, and how it helps our understanding of climate change by looking at it like an old frozen turkey, for example?
FREDERICK: Yeah, so permafrost is frozen ground. And just like when you put, you know, leftover turkey into the freezer, it has accumulated a bunch of organic matter. And organic matter is made up of a lot of carbon, which when it thaws out, and becomes available to microbes that are just living in the ground. They eat it up and create waste gases, those waste gases are greenhouse gases. And as you continually thaw and accelerate the thaw of permafrost, you're just giving more food basically, to the microbes. They're releasing more and more of these greenhouse gases, which of course then impacts how global warming progresses on Earth.
KUNM: Jenn, you're looking at the temperature aspect of this project. What questions are you trying to answer with this research?
FREDERICK: We're really interested in seafloor temperature, especially how it changes in space along the path of the cable going offshore, and then also how it changes in time. So, over weeks, months, seasons, even annually. The reason we're interested in temperature over time is because we'd like to understand how permafrost is degrading, how it's dying out and warming up, what that rate is, and if we could spot areas of warm spots on the seafloor or anomalies. We think those might indicate locations where there's seafloor “seeps,” and we're interested in seeps because they tend to bring carbon rich fluids and gases. So, they're also carrying gases like methane.
KUNM: Looking forward, how do you think your research will be used to innovate or even understand our climate? It sounds like there's room for improvement too.
STANCIU: One thing we can do is generate an image today. Five years from now, or 10 years from now we generate another image and we compare them to each other. And then we can infer some information about the evolution of the structure in that region. However, we are time limited. And I believe this is where Jenn's research is very valuable, in the sense that they can do predictions.
FREDERICK: Another piece of this project is not just the sensing component, but also understanding how the submarine permafrost changes over decades and centuries. How has the permafrost come to be from the last ice age up to this point? And then more importantly, how is it going to evolve into the future? How fast or rapidly will the permafrost thaw and how much greenhouse gas emissions would we expect?
