Scientists Bury GPS in Antarctic Ice to Measure Effects of Tides

1. 0:05I'm Ryan Walker. I work here at the Cryospheric Sciences Lab.
2. 0:10I work on computer simulations of the Antarctic and Greenland ice sheets.
3. 0:16to project how much of the ice is going from land into the ocean because it's possibly
4. 0:22an important contributor to sea level rise under climate change.
5. 0:28My name is Christine Dyer.
6. 0:30I'm researching sub-antarctic lake developments, so using numerical models to see how water
7. 0:36builds up and depletes underneath the Antarctic ice sheets.
8. 0:40So we went to the new South Korean research station Jang Bogo at Terra Nova Bay not too far from
9. 0:50the United States McMurdo base.
10. 0:52The Korea Polar Research Institute
11. 0:54fed and housed us for five weeks and provided helicopters and worked with us.
12. 1:00It was something that we absolutely could not have done without them.
13. 1:04In this first study, we were looking at how the ocean tides affect the motion both horizontally and vertically
14. 1:12of the Nansen Ice Shelf.
15. 1:14Examining how the ice shelf responds to tides helps us get at the dynamics of how the ice flows and
16. 1:23we're hoping will help future computer simulations.
17. 1:29In order to get over to the Nansen Ice Shelf you fly over extremely dramatic cliffs, very large areas of ice cravassing.
18. 1:40So it's quite spectacular on the way over.
19. 1:44There was one particular moment, actually, when we first arrived to our tilt meter site.
20. 1:48There was no wind at all and there was quite a lot of snow around.
21. 1:50And the most poignant thing I think was the silence.
22. 1:56When the helicopter shut down, nobody was talking.
23. 1:58You could not hear a single thing and that's such an usual thing to be able to find in the world.
24. 2:02No plane noises, no electricity noises, just absolutely nothing.
25. 2:06And it was one of the most spectacular places I've ever been.
26. 2:13The Antarctic ice sheet is flowing under its own weight spreading out from the center of the continent out
27. 2:20to the edges and when it reaches the ocean it goes afloat as ice shelves.
28. 2:25And where you have ice shelves that are in bays where the ice contact with the rock walls
29. 2:33this friction acts to hold back the ice flow, so in some sense these smaller ice shelves are like corks.
30. 2:41So as soon as you remove them, there's nothing preventing the ice mass from moving quick down.
31. 2:47If these calve off, if these break off right back to where the ice is resting on land
32. 2:52it can speed up dramatically and it's particular worry at the moment that the ice shelves around the Antarctic
33. 2:57are going to break up and then we're going to see an unprecedented speed up in the ice coming out
34. 3:02of the center of the ice sheet.

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