The Ice Thumpers | Continent 7: Antarctica

CHRISTIAN OHNEISER: I'm pretty certain that we're going to lose the actual ice shelf itself and parts of the West Antarctic Ice Sheet at some point in the future. It will turn into water. But it's where that water goes and how much of it turns actually into sea level that's the big question, right? Six to seven meters requires a whole reorganization of how we live and our civilization because you—you write off some of the most populated parts of the world, you know? Downtown London—well, I guess that's gone.

NARRATOR: In order to study the ice shelf's geological history, they need to find sediment on the sea floor beneath it so they can sample it as part of the project in future years. I mean, we can throw the stream right now and then thump our way along. We just want to make sure that—that this is the right place. You know, we've just dragged all this equipment out here. The immediate goal is just see the sea floor—make sure it's there and that it's flat and smooth and that there aren't big rocks in the way. What number are we up to?

LAURINE VAN HAASTRECHT: 17!

CHRISTIAN OHNEISER: For the science world, this is a big deal. You know, we're talking about megabucks for us, a lot of time—a lot of effort from a lot of people. This has a lot riding on it.

NARRATOR: To determine if they're in the right spot, the team will launch a hydraulically-driven 500-pound weight called The Thumper at the ice, then use the reflected sound heard by 96 geological microphones to create a picture of what they can't see. Basically, we're slicing through the ice shelf, through the ocean, and into the sea floor. We turn that slice on its side. And then we can see the different layers inside the ocean. We actually tap the snow out of these things.

CHRISTIAN OHNEISER: So we don't have a short circuit, right?

MAN: Exactly.

CHRISTIAN OHNEISER: So our goal is to actually get that picture of what's underneath the ice shelf. And we hope that our research will impact those people that decide, right, climate change—this is a problem now. This carbon dioxide is going to kill the ice. It's going to melt it. And we're going to be in trouble. We've been building equipment for six months. And we're just really excited to actually get into it.

LAURINE VAN HAASTRECHT: Ready?

CHRISTIAN OHNEISER: Yup! [thump] [impressed laughter]

LAURINE VAN HAASTRECHT: There it was.

CHRISTIAN OHNEISER: You can feel that!

MAN: It didn't trigger.

LAURINE VAN HAASTRECHT: Uh-oh. Is it triggering on the way up?

MAN: It triggered, though.

CHRISTIAN OHNEISER: Well, [bleep]. That's not good.

LAURINE VAN HAASTRECHT: That's just the way it drops. It hit the switch. And it triggers the system and basically triggers the microphones to start listening. For some reason, it's not doing it when the weight goes down but when the weight goes up. So we're just trying to sort figure out why it's doing that. [thud]

MAN: It didn't trigger again.

NARRATOR: If The Thumper and geophones are even milliseconds out of sync, the results are worthless.

LAURINE VAN HAASTRECHT: I think I can see the problem. The sled has got too many links at the back. So now it's not centered properly. I think we need to pull back from it slightly. All of our systems have come from different areas around the globe. So our geophone streamer came from Germany. Our computer system and the geodes, they came from the States. So it is a little bit nerve wracking to see whether all of those components do interact and whether they work in an Antarctic environment. [thud]

MAN: OK, it triggered. So that's good.

LAURINE VAN HAASTRECHT: So we're ready to move up?

MAN: Yup, move up.

LAURINE VAN HAASTRECHT: If our team is unsuccessful for finding a proper location, then it is basically the end of that aspect of the program. So I think we are a little bit worried. [thud]