WEBVTT

1
00:00:05.100 --> 00:00:09.980
I'm Ryan Walker. I work here at the Cryospheric Sciences Lab.

2
00:00:10.000 --> 00:00:15.930
I work on computer simulations of the Antarctic and Greenland ice sheets.

3
00:00:15.950 --> 00:00:21.630
to project how much of the ice is going from land into the ocean because it's possibly

4
00:00:21.650 --> 00:00:28.030
an important contributor to sea level rise under climate change.

5
00:00:28.050 --> 00:00:29.680
My name is Christine Dyer.

6
00:00:29.700 --> 00:00:36.270
I'm researching sub-antarctic lake developments, so using numerical models to see how water

7
00:00:36.290 --> 00:00:40.480
builds up and depletes underneath the Antarctic ice sheets.

8
00:00:40.500 --> 00:00:49.730
So we went to the new South Korean research station Jang Bogo at Terra Nova Bay not too far from

9
00:00:49.750 --> 00:00:52.260
the United States McMurdo base.

10
00:00:52.280 --> 00:00:54.430
The Korea Polar Research Institute

11
00:00:54.450 --> 00:00:59.880
fed and housed us for five weeks and provided helicopters and worked with us.

12
00:00:59.900 --> 00:01:04.240
It was something that we absolutely could not have done without them.

13
00:01:04.260 --> 00:01:11.810
In this first study, we were looking at how the ocean tides affect the motion both horizontally and vertically

14
00:01:11.830 --> 00:01:14.380
of the Nansen Ice Shelf.

15
00:01:14.400 --> 00:01:23.320
Examining how the ice shelf responds to tides helps us get at the dynamics of how the ice flows and

16
00:01:23.340 --> 00:01:28.730
we're hoping will help future computer simulations.

17
00:01:28.750 --> 00:01:39.950
In order to get over to the Nansen Ice Shelf you fly over extremely dramatic cliffs, very large areas of ice cravassing.

18
00:01:39.970 --> 00:01:44.080
So it's quite spectacular on the way over.

19
00:01:44.100 --> 00:01:47.650
There was one particular moment, actually, when we first arrived to our tilt meter site.

20
00:01:47.670 --> 00:01:50.130
There was no wind at all and there was quite a lot of snow around.

21
00:01:50.150 --> 00:01:55.510
And the most poignant thing I think was the silence.

22
00:01:55.530 --> 00:01:57.530
When the helicopter shut down, nobody was talking.

23
00:01:57.550 --> 00:02:01.880
You could not hear a single thing and that's such an usual thing to be able to find in the world.

24
00:02:01.900 --> 00:02:05.720
No plane noises, no electricity noises, just absolutely nothing.

25
00:02:05.740 --> 00:02:12.780
And it was one of the most spectacular places I've ever been.

26
00:02:12.800 --> 00:02:19.540
The Antarctic ice sheet is flowing under its own weight spreading out from the center of the continent out

27
00:02:19.560 --> 00:02:25.080
to the edges and when it reaches the ocean it goes afloat as ice shelves.

28
00:02:25.100 --> 00:02:32.990
And where you have ice shelves that are in bays where the ice contact with the rock walls

29
00:02:33.010 --> 00:02:40.970
this friction acts to hold back the ice flow, so in some sense these smaller ice shelves are like corks.

30
00:02:40.990 --> 00:02:47.250
So as soon as you remove them, there's nothing preventing the ice mass from moving quick down.

31
00:02:47.270 --> 00:02:52.210
If these calve off, if these break off right back to where the ice is resting on land

32
00:02:52.230 --> 00:02:57.230
it can speed up dramatically and it's particular worry at the moment that the ice shelves around the Antarctic

33
00:02:57.250 --> 00:03:01.770
are going to break up and then we're going to see an unprecedented speed up in the ice coming out

34
00:03:01.790 --> 00:03:04.100
of the center of the ice sheet.