[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:04.09,0:00:06.63,Default,,0000,0000,0000,,I wanted to start out by saying to you
Dialogue: 0,0:00:06.66,0:00:09.60,Default,,0000,0000,0000,,that my younger brother\Nis actually a journalist
Dialogue: 0,0:00:09.62,0:00:13.77,Default,,0000,0000,0000,,and he's told me that he writes an article\Nin about an hour or so.
Dialogue: 0,0:00:13.78,0:00:15.24,Default,,0000,0000,0000,,It gets posted online,
Dialogue: 0,0:00:15.27,0:00:19.67,Default,,0000,0000,0000,,and within that day about 100,000 people\Nmight read that article.
Dialogue: 0,0:00:20.05,0:00:23.31,Default,,0000,0000,0000,,I could spend maybe a couple of years\Nplanning an expedition,
Dialogue: 0,0:00:23.34,0:00:25.82,Default,,0000,0000,0000,,a couple more years writing that article,
Dialogue: 0,0:00:25.85,0:00:30.54,Default,,0000,0000,0000,,and if my article is very well received -\Nor perhaps very badly received -
Dialogue: 0,0:00:30.55,0:00:34.10,Default,,0000,0000,0000,,it might be cited about a hundred times\Nover the next ten years.
Dialogue: 0,0:00:34.14,0:00:38.39,Default,,0000,0000,0000,,So Im'never going to receive\Nthe same statistics as my younger brother.
Dialogue: 0,0:00:38.43,0:00:41.78,Default,,0000,0000,0000,,However, this afternoon\Nyou're helping me to do a little better,
Dialogue: 0,0:00:41.82,0:00:43.95,Default,,0000,0000,0000,,so thank you for your attention.
Dialogue: 0,0:00:44.40,0:00:48.55,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:00:48.79,0:00:52.08,Default,,0000,0000,0000,,So, I hope anyhow you'll find\Nwhat I'm going to say very interesting.
Dialogue: 0,0:00:52.25,0:00:53.70,Default,,0000,0000,0000,,I'm an ocean chemist.
Dialogue: 0,0:00:53.72,0:00:55.84,Default,,0000,0000,0000,,I look at the chemistry\Nof the ocean today.
Dialogue: 0,0:00:55.87,0:00:58.87,Default,,0000,0000,0000,,I look at the chemistry\Nof the ocean in the past.
Dialogue: 0,0:00:58.89,0:01:00.95,Default,,0000,0000,0000,,The way I look back in the past
Dialogue: 0,0:01:00.98,0:01:04.13,Default,,0000,0000,0000,,is by using the fossilized remains\Nof deepwater corals.
Dialogue: 0,0:01:04.15,0:01:06.80,Default,,0000,0000,0000,,You can see an image of one\Nof these corals behind me.
Dialogue: 0,0:01:06.82,0:01:11.24,Default,,0000,0000,0000,,It was collected from close to Antarctica,\Nthousands of meters below the sea,
Dialogue: 0,0:01:11.27,0:01:13.36,Default,,0000,0000,0000,,so, very different\Nthan the kinds of corals
Dialogue: 0,0:01:13.38,0:01:17.17,Default,,0000,0000,0000,,you may have been lucky enough to see\Nif you've had a tropical holiday.
Dialogue: 0,0:01:17.19,0:01:19.25,Default,,0000,0000,0000,,So I'm hoping that this talk will give you
Dialogue: 0,0:01:19.27,0:01:21.06,Default,,0000,0000,0000,,a four-dimensional view of the ocean.
Dialogue: 0,0:01:21.09,0:01:25.60,Default,,0000,0000,0000,,Two dimensions, such as this\Nbeautiful two-dimensional image
Dialogue: 0,0:01:25.63,0:01:27.22,Default,,0000,0000,0000,,of the sea surface temperature.
Dialogue: 0,0:01:27.25,0:01:31.27,Default,,0000,0000,0000,,This was taken using satellite,\Nso it's got tremendous spatial resolution.
Dialogue: 0,0:01:31.100,0:01:34.86,Default,,0000,0000,0000,,The overall features are extremely\Neasy to understand.
Dialogue: 0,0:01:34.89,0:01:38.55,Default,,0000,0000,0000,,The equatorial regions are warm\Nbecause there's more sunlight.
Dialogue: 0,0:01:39.18,0:01:41.86,Default,,0000,0000,0000,,The polar regions are cold\Nbecause there's less sunlight.
Dialogue: 0,0:01:41.89,0:01:44.81,Default,,0000,0000,0000,,And that allows big icecaps\Nto build up on Antarctica
Dialogue: 0,0:01:44.83,0:01:46.64,Default,,0000,0000,0000,,and up in the Northern Hemisphere.
Dialogue: 0,0:01:46.100,0:01:50.42,Default,,0000,0000,0000,,If you plunge deep into the sea,\Nor even put your toes in the sea,
Dialogue: 0,0:01:50.44,0:01:52.38,Default,,0000,0000,0000,,you know it gets colder as you go down,
Dialogue: 0,0:01:52.41,0:01:56.39,Default,,0000,0000,0000,,and that's mostly because the deep waters\Nthat fill the abyss of the ocean
Dialogue: 0,0:01:56.41,0:01:59.58,Default,,0000,0000,0000,,come from the cold polar regions\Nwhere the waters are dense.
Dialogue: 0,0:02:01.34,0:02:04.45,Default,,0000,0000,0000,,If we travel back in time\N20,000 years ago,
Dialogue: 0,0:02:04.48,0:02:06.34,Default,,0000,0000,0000,,the earth looked very much different.
Dialogue: 0,0:02:06.36,0:02:09.83,Default,,0000,0000,0000,,And I've just given you a cartoon version\Nof one of the major differences
Dialogue: 0,0:02:09.85,0:02:12.10,Default,,0000,0000,0000,,you would have seen\Nif you went back that long.
Dialogue: 0,0:02:12.13,0:02:13.81,Default,,0000,0000,0000,,The icecaps were much bigger.
Dialogue: 0,0:02:13.84,0:02:17.46,Default,,0000,0000,0000,,They covered lots of the continent,\Nand they extended out over the ocean.
Dialogue: 0,0:02:17.49,0:02:19.98,Default,,0000,0000,0000,,Sea level was 120 meters lower.
Dialogue: 0,0:02:20.00,0:02:23.55,Default,,0000,0000,0000,,Carbon dioxide [levels] were very\Nmuch lower than they are today.
Dialogue: 0,0:02:23.57,0:02:27.22,Default,,0000,0000,0000,,So the earth was probably about three\Nto five degrees colder overall,
Dialogue: 0,0:02:27.24,0:02:30.06,Default,,0000,0000,0000,,and much, much colder\Nin the polar regions.
Dialogue: 0,0:02:32.01,0:02:33.46,Default,,0000,0000,0000,,What I'm trying to understand,
Dialogue: 0,0:02:33.49,0:02:36.29,Default,,0000,0000,0000,,and what other colleagues of mine\Nare trying to understand,
Dialogue: 0,0:02:36.31,0:02:38.77,Default,,0000,0000,0000,,is how we moved from that\Ncold climate condition
Dialogue: 0,0:02:38.80,0:02:41.69,Default,,0000,0000,0000,,to the warm climate condition\Nthat we enjoy today.
Dialogue: 0,0:02:41.72,0:02:43.77,Default,,0000,0000,0000,,We know from ice core research -
Dialogue: 0,0:02:43.91,0:02:45.94,Default,,0000,0000,0000,,and in fact this is a picture\Nof an iceberg
Dialogue: 0,0:02:45.97,0:02:48.12,Default,,0000,0000,0000,,taken by one of my colleagues,\NDann Blackwood,
Dialogue: 0,0:02:48.14,0:02:49.77,Default,,0000,0000,0000,,down in the Southern Ocean -
Dialogue: 0,0:02:49.80,0:02:52.88,Default,,0000,0000,0000,,that the transition from these\Ncold conditions to warm conditions
Dialogue: 0,0:02:52.90,0:02:57.65,Default,,0000,0000,0000,,wasn't smooth, as you might predict\Nfrom the slow increase in solar radiation.
Dialogue: 0,0:02:58.45,0:03:01.68,Default,,0000,0000,0000,,And we know this from ice cores,\Nbecause if you drill down into ice,
Dialogue: 0,0:03:01.71,0:03:04.98,Default,,0000,0000,0000,,you find annual bands of ice,\Nand you can see this in the iceberg.
Dialogue: 0,0:03:05.00,0:03:06.99,Default,,0000,0000,0000,,You can see those blue-white layers.
Dialogue: 0,0:03:07.02,0:03:10.64,Default,,0000,0000,0000,,Gases are trapped in the ice cores,\Nso we can measure CO2 --
Dialogue: 0,0:03:10.67,0:03:13.03,Default,,0000,0000,0000,,that's why we know CO2\Nwas lower in the past --
Dialogue: 0,0:03:13.06,0:03:16.05,Default,,0000,0000,0000,,and the chemistry of the ice\Nalso tells us about temperature
Dialogue: 0,0:03:16.07,0:03:17.55,Default,,0000,0000,0000,,in the polar regions.
Dialogue: 0,0:03:17.57,0:03:21.25,Default,,0000,0000,0000,,And if you move in time\Nfrom 20,000 years ago to the modern day,
Dialogue: 0,0:03:21.28,0:03:23.08,Default,,0000,0000,0000,,you see that temperature increased.
Dialogue: 0,0:03:23.11,0:03:24.73,Default,,0000,0000,0000,,It didn't increase smoothly.
Dialogue: 0,0:03:24.76,0:03:26.54,Default,,0000,0000,0000,,Sometimes it increased very rapidly,
Dialogue: 0,0:03:26.56,0:03:27.80,Default,,0000,0000,0000,,then there was a plateau,
Dialogue: 0,0:03:27.83,0:03:29.09,Default,,0000,0000,0000,,then it increased rapidly.
Dialogue: 0,0:03:29.12,0:03:31.14,Default,,0000,0000,0000,,It was different in the two polar regions,
Dialogue: 0,0:03:31.16,0:03:33.89,Default,,0000,0000,0000,,and CO2 also increased in jumps.
Dialogue: 0,0:03:35.11,0:03:38.15,Default,,0000,0000,0000,,So we're pretty sure the ocean\Nhas a lot to do with this.
Dialogue: 0,0:03:38.18,0:03:40.54,Default,,0000,0000,0000,,The ocean stores huge amounts of carbon,
Dialogue: 0,0:03:40.57,0:03:43.12,Default,,0000,0000,0000,,about 60 times more\Nthan is in the atmosphere.
Dialogue: 0,0:03:43.15,0:03:46.35,Default,,0000,0000,0000,,It also acts to transport heat\Nacross the equator,
Dialogue: 0,0:03:46.37,0:03:50.14,Default,,0000,0000,0000,,and the ocean is full of nutrients\Nand it controls primary productivity.
Dialogue: 0,0:03:52.04,0:03:55.82,Default,,0000,0000,0000,,So if we want to get down and find out\Nwhat's going on down in the deep sea,
Dialogue: 0,0:03:55.85,0:03:57.44,Default,,0000,0000,0000,,we really need to get down there,
Dialogue: 0,0:03:57.47,0:03:58.63,Default,,0000,0000,0000,,see what's there
Dialogue: 0,0:03:58.66,0:04:00.06,Default,,0000,0000,0000,,and start to explore.
Dialogue: 0,0:04:00.08,0:04:03.09,Default,,0000,0000,0000,,This is some spectacular footage\Ncoming from a seamount
Dialogue: 0,0:04:03.12,0:04:05.30,Default,,0000,0000,0000,,about a kilometer deep\Nin international waters
Dialogue: 0,0:04:05.33,0:04:08.31,Default,,0000,0000,0000,,in the equatorial Atlantic, far from land.
Dialogue: 0,0:04:08.33,0:04:11.38,Default,,0000,0000,0000,,You're amongst the first people\Nto see this bit of the seafloor,
Dialogue: 0,0:04:11.41,0:04:13.05,Default,,0000,0000,0000,,along with my research team.
Dialogue: 0,0:04:14.04,0:04:15.78,Default,,0000,0000,0000,,You're probably seeing new species.
Dialogue: 0,0:04:15.81,0:04:16.96,Default,,0000,0000,0000,,We don't know.
Dialogue: 0,0:04:16.98,0:04:20.64,Default,,0000,0000,0000,,You'd have to collect the samples\Nand do some very intense taxonomy.
Dialogue: 0,0:04:20.67,0:04:22.56,Default,,0000,0000,0000,,You can see beautiful bubblegum corals.
Dialogue: 0,0:04:22.58,0:04:24.84,Default,,0000,0000,0000,,There are brittle stars\Ngrowing on these corals.
Dialogue: 0,0:04:24.86,0:04:27.92,Default,,0000,0000,0000,,Those are things that look\Nlike tentacles coming out of corals.
Dialogue: 0,0:04:27.94,0:04:30.82,Default,,0000,0000,0000,,There are corals made of different forms\Nof calcium carbonate
Dialogue: 0,0:04:30.84,0:04:35.38,Default,,0000,0000,0000,,growing off the basalt of this\Nmassive undersea mountain,
Dialogue: 0,0:04:35.44,0:04:38.80,Default,,0000,0000,0000,,and the dark sort of stuff,\Nthose are fossilized corals,
Dialogue: 0,0:04:38.83,0:04:41.14,Default,,0000,0000,0000,,and we're going to talk\Na little more about those
Dialogue: 0,0:04:41.16,0:04:42.51,Default,,0000,0000,0000,,as we travel back in time.
Dialogue: 0,0:04:42.93,0:04:45.42,Default,,0000,0000,0000,,To do that, we need\Nto charter a research boat.
Dialogue: 0,0:04:45.44,0:04:48.48,Default,,0000,0000,0000,,This is the James Cook,\Nan ocean-class research vessel
Dialogue: 0,0:04:48.50,0:04:49.77,Default,,0000,0000,0000,,moored up in Tenerife.
Dialogue: 0,0:04:49.80,0:04:51.13,Default,,0000,0000,0000,,Looks beautiful, right?
Dialogue: 0,0:04:51.45,0:04:53.28,Default,,0000,0000,0000,,Great, if you're not a great mariner.
Dialogue: 0,0:04:53.60,0:04:56.11,Default,,0000,0000,0000,,Sometimes it looks\Na little more like this.
Dialogue: 0,0:04:56.13,0:04:59.33,Default,,0000,0000,0000,,This is us trying to make sure\Nthat we don't lose precious samples.
Dialogue: 0,0:04:59.35,0:05:02.17,Default,,0000,0000,0000,,Everyone's scurrying around,\Nand I get terribly seasick,
Dialogue: 0,0:05:02.19,0:05:05.19,Default,,0000,0000,0000,,so it's not always a lot of fun,\Nbut overall it is.
Dialogue: 0,0:05:06.21,0:05:08.80,Default,,0000,0000,0000,,So we've got to become\Na really good mapper to do this.
Dialogue: 0,0:05:08.82,0:05:12.56,Default,,0000,0000,0000,,You don't see that kind of spectacular\Ncoral abundance everywhere.
Dialogue: 0,0:05:12.58,0:05:15.87,Default,,0000,0000,0000,,It is global and it is deep,
Dialogue: 0,0:05:16.15,0:05:18.46,Default,,0000,0000,0000,,but we need to really find\Nthe right places.
Dialogue: 0,0:05:18.49,0:05:21.65,Default,,0000,0000,0000,,We just saw a global map,\Nand overlaid was our cruise passage
Dialogue: 0,0:05:21.68,0:05:22.88,Default,,0000,0000,0000,,from last year.
Dialogue: 0,0:05:23.39,0:05:24.79,Default,,0000,0000,0000,,This was a seven-week cruise,
Dialogue: 0,0:05:24.81,0:05:26.83,Default,,0000,0000,0000,,and this is us, having made our own maps
Dialogue: 0,0:05:26.86,0:05:30.93,Default,,0000,0000,0000,,of about 75,000 square kilometers\Nof the seafloor in seven weeks,
Dialogue: 0,0:05:30.95,0:05:33.48,Default,,0000,0000,0000,,but that's only a tiny fraction\Nof the seafloor.
Dialogue: 0,0:05:33.50,0:05:35.27,Default,,0000,0000,0000,,We're traveling from west to east,
Dialogue: 0,0:05:35.29,0:05:38.79,Default,,0000,0000,0000,,over part of the ocean that would\Nlook featureless on a big-scale map,
Dialogue: 0,0:05:38.82,0:05:42.07,Default,,0000,0000,0000,,but actually some of these mountains\Nare as big as Everest.
Dialogue: 0,0:05:42.60,0:05:44.53,Default,,0000,0000,0000,,So with the maps that we make on board,
Dialogue: 0,0:05:44.55,0:05:46.54,Default,,0000,0000,0000,,we get about 100-meter resolution,
Dialogue: 0,0:05:46.57,0:05:49.46,Default,,0000,0000,0000,,enough to pick out areas\Nto deploy our equipment,
Dialogue: 0,0:05:49.48,0:05:51.39,Default,,0000,0000,0000,,but not enough to see very much.
Dialogue: 0,0:05:51.42,0:05:54.14,Default,,0000,0000,0000,,To do that, we need to fly\Nremotely-operated vehicles
Dialogue: 0,0:05:54.16,0:05:56.38,Default,,0000,0000,0000,,about five meters off the seafloor.
Dialogue: 0,0:05:56.40,0:05:59.62,Default,,0000,0000,0000,,And if we do that, we can get maps\Nthat are one-meter resolution
Dialogue: 0,0:05:59.64,0:06:01.73,Default,,0000,0000,0000,,down thousands of meters.
Dialogue: 0,0:06:02.26,0:06:04.08,Default,,0000,0000,0000,,Here is a remotely-operated vehicle,
Dialogue: 0,0:06:04.10,0:06:06.41,Default,,0000,0000,0000,,a research-grade vehicle.
Dialogue: 0,0:06:06.43,0:06:08.92,Default,,0000,0000,0000,,You can see an array\Nof big lights on the top.
Dialogue: 0,0:06:08.94,0:06:11.100,Default,,0000,0000,0000,,There are high-definition cameras,\Nmanipulator arms,
Dialogue: 0,0:06:12.02,0:06:14.93,Default,,0000,0000,0000,,and lots of little boxes and things\Nto put your samples.
Dialogue: 0,0:06:15.49,0:06:19.20,Default,,0000,0000,0000,,Here we are on our first dive\Nof this particular cruise,
Dialogue: 0,0:06:19.23,0:06:20.94,Default,,0000,0000,0000,,plunging down into the ocean.
Dialogue: 0,0:06:20.96,0:06:23.83,Default,,0000,0000,0000,,We go pretty fast to make sure\Nthe remotely operated vehicles
Dialogue: 0,0:06:23.86,0:06:26.89,Default,,0000,0000,0000,,are not affected by any other ships -\Nparts of the ship.
Dialogue: 0,0:06:27.38,0:06:30.05,Default,,0000,0000,0000,,You can see the bubbles going,\NI quite like that footage.
Dialogue: 0,0:06:30.08,0:06:31.28,Default,,0000,0000,0000,,And we go down,
Dialogue: 0,0:06:31.30,0:06:33.48,Default,,0000,0000,0000,,and these are the kinds of things you see.
Dialogue: 0,0:06:33.50,0:06:37.00,Default,,0000,0000,0000,,These are deep sea sponges, meter scale.
Dialogue: 0,0:06:37.62,0:06:41.86,Default,,0000,0000,0000,,This is a swimming holothurian --\Nit's a small sea slug, basically.
Dialogue: 0,0:06:41.89,0:06:43.08,Default,,0000,0000,0000,,This is slowed down.
Dialogue: 0,0:06:43.10,0:06:45.49,Default,,0000,0000,0000,,Most of the footage I'm showing\Nyou is speeded up,
Dialogue: 0,0:06:45.51,0:06:47.44,Default,,0000,0000,0000,,because all of this takes a lot of time.
Dialogue: 0,0:06:48.27,0:06:51.21,Default,,0000,0000,0000,,This is a beautiful holothurian as well.
Dialogue: 0,0:06:51.70,0:06:54.77,Default,,0000,0000,0000,,And this animal you're going to see\Ncoming up was a big surprise.
Dialogue: 0,0:06:54.79,0:06:58.20,Default,,0000,0000,0000,,I've never seen anything like this\Nand it took us all a bit surprised.
Dialogue: 0,0:06:58.23,0:07:01.72,Default,,0000,0000,0000,,This was after about 15 hours of work\Nand we were all a bit trigger-happy,
Dialogue: 0,0:07:01.74,0:07:04.48,Default,,0000,0000,0000,,and suddenly this giant\Nsea monster started rolling past.
Dialogue: 0,0:07:04.51,0:07:07.61,Default,,0000,0000,0000,,It's called a pyrosome\Nor colonial tunicate, if you like.
Dialogue: 0,0:07:07.73,0:07:09.52,Default,,0000,0000,0000,,This wasn't what we were looking for.
Dialogue: 0,0:07:09.54,0:07:12.19,Default,,0000,0000,0000,,We were looking for corals,\Ndeep sea corals.
Dialogue: 0,0:07:12.99,0:07:15.29,Default,,0000,0000,0000,,You're going to see a picture\Nof one in a moment.
Dialogue: 0,0:07:15.32,0:07:17.95,Default,,0000,0000,0000,,It's small, about five centimeters high.
Dialogue: 0,0:07:17.98,0:07:21.29,Default,,0000,0000,0000,,It's made of calcium carbonate,\Nso you can see its tentacles there,
Dialogue: 0,0:07:21.32,0:07:23.45,Default,,0000,0000,0000,,moving in the ocean currents.
Dialogue: 0,0:07:23.98,0:07:27.09,Default,,0000,0000,0000,,An organism like this probably lives\Nfor about a hundred years.
Dialogue: 0,0:07:27.12,0:07:30.66,Default,,0000,0000,0000,,And as it grows, it takes in\Nchemicals from the ocean.
Dialogue: 0,0:07:30.68,0:07:32.88,Default,,0000,0000,0000,,And the chemicals,\Nor the amount of chemicals,
Dialogue: 0,0:07:32.91,0:07:35.58,Default,,0000,0000,0000,,depends on the temperature;\Nit depends on the pH,
Dialogue: 0,0:07:35.61,0:07:37.15,Default,,0000,0000,0000,,it depends on the nutrients.
Dialogue: 0,0:07:37.18,0:07:40.41,Default,,0000,0000,0000,,And if we can understand how\Nthese chemicals get into the skeleton,
Dialogue: 0,0:07:40.44,0:07:42.93,Default,,0000,0000,0000,,we can then go back,\Ncollect fossil specimens,
Dialogue: 0,0:07:42.96,0:07:46.10,Default,,0000,0000,0000,,and reconstruct what the ocean\Nused to look like in the past.
Dialogue: 0,0:07:46.42,0:07:49.86,Default,,0000,0000,0000,,And here you can see us collecting\Nthat coral with a vacuum system,
Dialogue: 0,0:07:49.88,0:07:51.24,Default,,0000,0000,0000,,pull it up,
Dialogue: 0,0:07:51.28,0:07:54.21,Default,,0000,0000,0000,,and we put it into a sampling container.
Dialogue: 0,0:07:54.41,0:07:56.47,Default,,0000,0000,0000,,We can do this very\Ncarefully, I should add.
Dialogue: 0,0:07:58.39,0:08:00.78,Default,,0000,0000,0000,,Some of these organisms live even longer.
Dialogue: 0,0:08:00.80,0:08:04.20,Default,,0000,0000,0000,,This is a black coral called Leiopathes,\Nan image taken by my colleague,
Dialogue: 0,0:08:04.23,0:08:07.49,Default,,0000,0000,0000,,Brendan Roark, about 500\Nmeters below Hawaii.
Dialogue: 0,0:08:08.31,0:08:10.36,Default,,0000,0000,0000,,Four thousand years is a long time.
Dialogue: 0,0:08:10.66,0:08:13.80,Default,,0000,0000,0000,,If you take a branch from one\Nof these corals and polish it up,
Dialogue: 0,0:08:13.82,0:08:16.11,Default,,0000,0000,0000,,this is about 100 microns across.
Dialogue: 0,0:08:16.46,0:08:19.21,Default,,0000,0000,0000,,And Brendan took some analyses\Nacross this coral --
Dialogue: 0,0:08:19.48,0:08:21.28,Default,,0000,0000,0000,,you can see the marks --
Dialogue: 0,0:08:21.31,0:08:24.27,Default,,0000,0000,0000,,and he's been able to show\Nthat these are actual annual bands,
Dialogue: 0,0:08:24.29,0:08:26.20,Default,,0000,0000,0000,,so even at 500 meters deep in the ocean,
Dialogue: 0,0:08:26.24,0:08:28.44,Default,,0000,0000,0000,,corals can record seasonal changes,
Dialogue: 0,0:08:28.52,0:08:30.25,Default,,0000,0000,0000,,which is pretty spectacular.
Dialogue: 0,0:08:30.28,0:08:34.07,Default,,0000,0000,0000,,But 4,000 years is not enough to get\Nus back to our last glacial maximum.
Dialogue: 0,0:08:34.10,0:08:35.26,Default,,0000,0000,0000,,So what do we do?
Dialogue: 0,0:08:35.28,0:08:37.29,Default,,0000,0000,0000,,We go in for these fossil specimens.
Dialogue: 0,0:08:37.88,0:08:40.81,Default,,0000,0000,0000,,This is what makes me really unpopular\Nwith my research team.
Dialogue: 0,0:08:40.84,0:08:41.98,Default,,0000,0000,0000,,So going along,
Dialogue: 0,0:08:42.01,0:08:43.63,Default,,0000,0000,0000,,there's giant sharks everywhere,
Dialogue: 0,0:08:43.65,0:08:46.15,Default,,0000,0000,0000,,there are pyrosomes,\Nthere are swimming holothurians,
Dialogue: 0,0:08:46.17,0:08:47.44,Default,,0000,0000,0000,,there's giant sponges,
Dialogue: 0,0:08:47.47,0:08:50.06,Default,,0000,0000,0000,,but I make everyone go down\Nto these dead fossil areas
Dialogue: 0,0:08:50.09,0:08:53.64,Default,,0000,0000,0000,,and spend ages kind of shoveling\Naround on the seafloor.
Dialogue: 0,0:08:53.67,0:08:57.03,Default,,0000,0000,0000,,And we pick up all these corals,\Nbring them back, we sort them out.
Dialogue: 0,0:08:57.06,0:08:59.35,Default,,0000,0000,0000,,But each one of these is a different age,
Dialogue: 0,0:08:59.38,0:09:01.28,Default,,0000,0000,0000,,and if we can find out how old they are
Dialogue: 0,0:09:01.30,0:09:03.81,Default,,0000,0000,0000,,and then we can measure\Nthose chemical signals,
Dialogue: 0,0:09:03.84,0:09:05.26,Default,,0000,0000,0000,,this helps us to find out
Dialogue: 0,0:09:05.28,0:09:07.76,Default,,0000,0000,0000,,what's been going on\Nin the ocean in the past.
Dialogue: 0,0:09:08.26,0:09:09.96,Default,,0000,0000,0000,,So on the left-hand image here,
Dialogue: 0,0:09:09.99,0:09:13.02,Default,,0000,0000,0000,,I've taken a slice through a coral,\Npolished it very carefully
Dialogue: 0,0:09:13.04,0:09:15.01,Default,,0000,0000,0000,,and taken an optical image.
Dialogue: 0,0:09:15.04,0:09:16.19,Default,,0000,0000,0000,,On the right-hand side,
Dialogue: 0,0:09:16.21,0:09:19.31,Default,,0000,0000,0000,,we've taken that same piece of coral,\Nput it in a nuclear reactor,
Dialogue: 0,0:09:19.34,0:09:20.49,Default,,0000,0000,0000,,induced fission,
Dialogue: 0,0:09:20.51,0:09:22.14,Default,,0000,0000,0000,,and every time there's some decay,
Dialogue: 0,0:09:22.17,0:09:24.15,Default,,0000,0000,0000,,you can see that marked out in the coral,
Dialogue: 0,0:09:24.17,0:09:26.06,Default,,0000,0000,0000,,so we can see the uranium distribution.
Dialogue: 0,0:09:26.09,0:09:27.24,Default,,0000,0000,0000,,Why are we doing this?
Dialogue: 0,0:09:27.26,0:09:29.55,Default,,0000,0000,0000,,Uranium is a very poorly regarded element,
Dialogue: 0,0:09:29.57,0:09:30.73,Default,,0000,0000,0000,,but I love it.
Dialogue: 0,0:09:30.76,0:09:33.97,Default,,0000,0000,0000,,The decay helps us find out\Nabout the rates and dates
Dialogue: 0,0:09:33.99,0:09:35.53,Default,,0000,0000,0000,,of what's going on in the ocean.
Dialogue: 0,0:09:35.55,0:09:37.45,Default,,0000,0000,0000,,And if you remember from the beginning,
Dialogue: 0,0:09:37.48,0:09:40.49,Default,,0000,0000,0000,,that's what we want to get at\Nwhen we're thinking about climate.
Dialogue: 0,0:09:40.51,0:09:42.26,Default,,0000,0000,0000,,So we use a laser to analyze uranium
Dialogue: 0,0:09:42.29,0:09:45.07,Default,,0000,0000,0000,,and one of its daughter products,\Nthorium, in these corals,
Dialogue: 0,0:09:45.10,0:09:47.74,Default,,0000,0000,0000,,and that tells us exactly\Nhow old the fossils are.
Dialogue: 0,0:09:49.44,0:09:51.63,Default,,0000,0000,0000,,This beautiful animation\Nof the Southern Ocean
Dialogue: 0,0:09:51.66,0:09:54.79,Default,,0000,0000,0000,,I'm just going to use illustrate\Nhow we're using these corals
Dialogue: 0,0:09:54.82,0:09:58.89,Default,,0000,0000,0000,,to get at some of the ancient\Nocean feedbacks.
Dialogue: 0,0:09:58.91,0:10:01.34,Default,,0000,0000,0000,,You can see the density\Nof the surface water
Dialogue: 0,0:10:01.36,0:10:03.76,Default,,0000,0000,0000,,in this animation by Ryan Abernathey.
Dialogue: 0,0:10:04.50,0:10:06.52,Default,,0000,0000,0000,,It's just one year of data,
Dialogue: 0,0:10:06.54,0:10:09.15,Default,,0000,0000,0000,,but you can see how dynamic\Nthe Southern Ocean is.
Dialogue: 0,0:10:09.50,0:10:14.08,Default,,0000,0000,0000,,The intense mixing,\Nparticularly the Great Passage,
Dialogue: 0,0:10:14.13,0:10:16.57,Default,,0000,0000,0000,,which is shown by the box,
Dialogue: 0,0:10:16.59,0:10:19.60,Default,,0000,0000,0000,,is really one of the strongest\Ncurrents in the world
Dialogue: 0,0:10:19.63,0:10:21.84,Default,,0000,0000,0000,,coming through here,\Nflowing from west to east.
Dialogue: 0,0:10:21.86,0:10:23.21,Default,,0000,0000,0000,,It's very turbulently mixed,
Dialogue: 0,0:10:23.23,0:10:26.10,Default,,0000,0000,0000,,because it's moving over those\Ngreat big undersea mountains,
Dialogue: 0,0:10:26.13,0:10:30.61,Default,,0000,0000,0000,,and this allows CO2 and heat to exchange\Nwith the atmosphere in and out.
Dialogue: 0,0:10:30.63,0:10:34.14,Default,,0000,0000,0000,,And essentially, the oceans are breathing\Nthrough the Southern Ocean.
Dialogue: 0,0:10:35.46,0:10:40.93,Default,,0000,0000,0000,,We've collected corals from back and forth\Nacross this Antarctic passage,
Dialogue: 0,0:10:40.95,0:10:43.98,Default,,0000,0000,0000,,and we've found quite a surprising thing\Nfrom my uranium dating:
Dialogue: 0,0:10:44.00,0:10:46.51,Default,,0000,0000,0000,,the corals migrated from south to north
Dialogue: 0,0:10:46.53,0:10:49.66,Default,,0000,0000,0000,,during this transition from the glacial\Nto the interglacial.
Dialogue: 0,0:10:49.68,0:10:50.89,Default,,0000,0000,0000,,We don't really know why,
Dialogue: 0,0:10:50.92,0:10:53.46,Default,,0000,0000,0000,,but we think it's something\Nto do with the food source
Dialogue: 0,0:10:53.49,0:10:55.44,Default,,0000,0000,0000,,and maybe the oxygen in the water.
Dialogue: 0,0:10:57.58,0:10:58.44,Default,,0000,0000,0000,,So here we are.
Dialogue: 0,0:10:58.47,0:11:01.52,Default,,0000,0000,0000,,I'm going to illustrate what I think\Nwe've found about climate
Dialogue: 0,0:11:01.54,0:11:03.50,Default,,0000,0000,0000,,from those corals in the Southern Ocean.
Dialogue: 0,0:11:03.53,0:11:06.80,Default,,0000,0000,0000,,We went up and down sea mountains.\NWe collected little fossil corals.
Dialogue: 0,0:11:06.83,0:11:08.35,Default,,0000,0000,0000,,This is my illustration of that.
Dialogue: 0,0:11:08.38,0:11:09.78,Default,,0000,0000,0000,,We think back in the glacial,
Dialogue: 0,0:11:09.81,0:11:11.83,Default,,0000,0000,0000,,from the analysis\Nwe've made in the corals,
Dialogue: 0,0:11:11.86,0:11:14.94,Default,,0000,0000,0000,,that the deep part of the Southern Ocean\Nwas very rich in carbon,
Dialogue: 0,0:11:14.99,0:11:17.68,Default,,0000,0000,0000,,and there was a low-density\Nlayer sitting on top.
Dialogue: 0,0:11:17.92,0:11:20.71,Default,,0000,0000,0000,,That stops carbon dioxide\Ncoming out of the ocean.
Dialogue: 0,0:11:21.55,0:11:24.14,Default,,0000,0000,0000,,We then found corals\Nthat are of an intermediate age,
Dialogue: 0,0:11:24.17,0:11:28.75,Default,,0000,0000,0000,,and they show us that the ocean mixed\Npartway through that climate transition.
Dialogue: 0,0:11:28.77,0:11:31.24,Default,,0000,0000,0000,,That allows carbon to come\Nout of the deep ocean.
Dialogue: 0,0:11:31.95,0:11:35.05,Default,,0000,0000,0000,,And then if we analyze corals\Ncloser to the modern day,
Dialogue: 0,0:11:35.08,0:11:37.33,Default,,0000,0000,0000,,or indeed if we go down there today anyway
Dialogue: 0,0:11:37.36,0:11:39.56,Default,,0000,0000,0000,,and measure the chemistry of the corals,
Dialogue: 0,0:11:39.58,0:11:43.58,Default,,0000,0000,0000,,we see that we move to a position\Nwhere carbon can exchange in and out.
Dialogue: 0,0:11:43.60,0:11:45.68,Default,,0000,0000,0000,,So this is the way\Nwe can use fossil corals
Dialogue: 0,0:11:45.70,0:11:47.64,Default,,0000,0000,0000,,to help us learn about the environment.
Dialogue: 0,0:11:49.63,0:11:51.76,Default,,0000,0000,0000,,So I want to leave you\Nwith this last slide.
Dialogue: 0,0:11:51.78,0:11:55.71,Default,,0000,0000,0000,,It's just a still taken out of that first\Npiece of footage that I showed you.
Dialogue: 0,0:11:55.73,0:11:57.84,Default,,0000,0000,0000,,This is a spectacular coral garden.
Dialogue: 0,0:11:57.87,0:12:00.43,Default,,0000,0000,0000,,We didn't even expect\Nto find things this beautiful.
Dialogue: 0,0:12:00.45,0:12:02.33,Default,,0000,0000,0000,,It's thousands of meters deep.
Dialogue: 0,0:12:02.36,0:12:03.73,Default,,0000,0000,0000,,There are new species.
Dialogue: 0,0:12:04.22,0:12:06.12,Default,,0000,0000,0000,,It's just a beautiful place.
Dialogue: 0,0:12:06.14,0:12:07.52,Default,,0000,0000,0000,,There are fossils in amongst,
Dialogue: 0,0:12:07.54,0:12:10.24,Default,,0000,0000,0000,,and now I've trained you\Nto appreciate the fossil corals
Dialogue: 0,0:12:10.26,0:12:11.47,Default,,0000,0000,0000,,that are down there.
Dialogue: 0,0:12:11.50,0:12:14.36,Default,,0000,0000,0000,,So next time you're lucky enough\Nto fly over the ocean
Dialogue: 0,0:12:14.39,0:12:15.80,Default,,0000,0000,0000,,or sail over the ocean,
Dialogue: 0,0:12:15.82,0:12:18.49,Default,,0000,0000,0000,,just think -- there are massive\Nsea mountains down there
Dialogue: 0,0:12:18.51,0:12:20.38,Default,,0000,0000,0000,,that nobody's ever seen before,
Dialogue: 0,0:12:20.40,0:12:22.02,Default,,0000,0000,0000,,and there are beautiful corals.
Dialogue: 0,0:12:22.04,0:12:23.20,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:12:23.22,0:12:28.15,Default,,0000,0000,0000,,(Applause)