The secrets I find on the mysterious ocean floor | Laura Robinson

Translator: Mario Cal Reviewer: Belén García Penerbosa

Well, I'm an ocean chemist.

Son química mariña.

Estudo as propiedades químicas actuais dos océanos.

I look at the chemistry of the ocean today.

I look at the chemistry of the ocean in the past.

E as propiedades químicas dos océanos no pasado.

The way I look back in the past

Para observar o pasado,

is by using the fossilized remains of deepwater corals.

utilizo restos fósiles de corais de augas profundas.

You can see an image of one of these corals behind me.

Detrás de min tedes unha imaxe dun destes corais.

It was collected from close to Antarctica, thousands of meters below the sea,

Foi recollido cerca da Antártida, a miles de metros de profundidade.

so, very different than the kinds of corals

Moi distinto, polo tanto, do tipo de corais

you may have been lucky enough to see if you've had a tropical holiday.

que se cadra tivestes a sorte de atopar se fostes de vacacións ao trópico.

So I'm hoping that this talk will give you

Con esta charla espero ofrecervos

a four-dimensional view of the ocean.

unha visión do océano en catro dimensións.

Two dimensions, such as this beautiful two-dimensional image

Dúas dimensións, como as desta fermosa imaxe, que representa

of the sea surface temperature.

a temperatura superficial do mar.

Tomouse vía satélite, polo que ten unha resolución espacial altísima.

This was taken using satellite, so it's got tremendous spatial resolution.

The overall features are extremely easy to understand.

Os trazos xerais son moi doados de entender.

The equatorial regions are warm because there's more sunlight.

As rexións ecuatoriais están máis quentes porque reciben máis luz solar.

The polar regions are cold because there's less sunlight.

As rexións polares están frías porque reciben menos luz.

Iso permite que se formen grandes capas de xeo na Antártida

And that allows big icecaps to build up on Antarctica

e no extremo do hemisferio norte.

and up in the Northern Hemisphere.

If you plunge deep into the sea, or even put your toes in the sea,

Se nos mergullamos no mar a gran profundidade, ou só metemos o pé,

you know it gets colder as you go down,

notamos máis frío canto máis descendemos,

and that's mostly because the deep waters that fill the abyss of the ocean

e iso ocorre sobre todo porque as augas profundas do abismo oceánico

come from the cold polar regions where the waters are dense.

proceden das frías rexións polares onde a densidade da auga é alta.

If we travel back in time 20,000 years ago,

Se retrocedésemos no tempo uns 20.000 anos,

the earth looked very much different.

a Terra tería un aspecto moi distinto.

And I've just given you a cartoon version of one of the major differences

Este debuxo representa unha das diferenzas máis importantes

you would have seen if you went back that long.

que veríamos se retrocedésemos todo ese tempo.

The icecaps were much bigger.

As capas de xeo eran moito maiores.

They covered lots of the continent, and they extended out over the ocean.

Cubrían gran parte do continente e estendíanse polo océano.

Sea level was 120 meters lower.

O nivel do mar era 120 metros máis baixo.

Carbon dioxide [levels] were very much lower than they are today.

Os niveis de dióxido de carbono eran moi inferiores aos actuais.

Así que a temperatura media da Terra era entre tres e cinco graos máis baixa,

So the earth was probably about three to five degrees colder overall,

and much, much colder in the polar regions.

e moitísimo máis baixa nas rexións polares.

What I'm trying to understand,

O que trato de entender,

and what other colleagues of mine are trying to understand,

coma outros colegas meus,

é como pasamos daquelas condicións climáticas frías

is how we moved from that cold climate condition

to the warm climate condition that we enjoy today.

ás condicións máis cálidas das que gozamos hoxe.

We know from ice core research

Sabemos pola análise de mostras de xeo

that the transition from these cold conditions to warm conditions

que a transición destas condicións frías a outras máis cálidas

wasn't smooth, as you might predict from the slow increase in solar radiation.

non foi gradual, como cabería predicir polo lento aumento da radiación solar.

Sabémolo polas mostras de xeo, porque, ao perforar o xeo,

And we know this from ice cores, because if you drill down into ice,

you find annual bands of ice, and you can see this in the iceberg.

atopamos bandas anuais, como podedes observar neste iceberg.

You can see those blue-white layers.

Son esas capas azuis e brancas.

Gases are trapped in the ice cores, so we can measure CO2 --

Os gases quedan atrapados no xeo, polo que podemos medir o CO2 --

that's why we know CO2 was lower in the past --

por iso sabemos que había menos CO2 no pasado--

and the chemistry of the ice also tells us about temperature

e a composición química do xeo dinos a temperatura

in the polar regions.

das rexións polares.

And if you move in time from 20,000 years ago to the modern day,

Se avanzamos dende hai 20.000 anos ata hoxe,

you see that temperature increased.

vemos que a temperatura aumentou.

It didn't increase smoothly.

Non aumentou de xeito gradual.

Sometimes it increased very rapidly,

Ás veces aumentaba moi rápido,

then there was a plateau,

logo estabilizábase,

then it increased rapidly.

logo aumentaba rápido.

It was different in the two polar regions,

Era distinta nas dúas rexións polares,

and CO2 also increased in jumps.

e o CO2 tamén aumentou a tiróns.

So we're pretty sure the ocean has a lot to do with this.

Así que estamos convencidos de que o océano ten moito que ver.

The ocean stores huge amounts of carbon,

O océano almacena cantidades enormes de carbono,

about 60 times more than is in the atmosphere.

60 veces máis do que hai na atmosfera.

It also acts to transport heat across the equator,

Tamén intervén no transporte de calor dun lado ao outro do ecuador,

e está cheo de nutrientes e controla a produtividade primaria.

and the ocean is full of nutrients and it controls primary productivity.

Así que se queremos saber o que pasa nas profundidades do mar,

So if we want to find out what's going on down in the deep sea,

temos que baixar alí,

we really need to get down there,

see what's there

ver o que hai

and start to explore.

e comezar a explorar.

Estas son imaxes espectaculares obtidas nun monte submarino

This is some spectacular footage coming from a seamount

a un quilómetro de profundidade en augas internacionais

about a kilometer deep in international waters

in the equatorial Atlantic, far from land.

na zona ecuatorial do Atlántico, lonxe de terra firme.

You're amongst the first people to see this bit of the seafloor,

Sodes dos primeiros en ver este anaco de fondo mariño,

along with my research team.

xunto co meu equipo.

You're probably seeing new species.

Igual estades vendo especies novas.

Non o sabemos.

We don't know.

You'd have to collect the samples and do some very intense taxonomy.

Habería que recoller as mostras e facer unha análise taxonómica rigorosa.

You can see beautiful bubblegum corals.

Aquí vedes o fermoso Paragorgia arborea.

There are brittle stars growing on these corals.

Nestes corais viven ofiuras.

Son esas cousas con forma de tentáculo que saen dos corais.

Those are things that look like tentacles coming out of corals.

There are corals made of different forms of calcium carbonate

Corais de distintas formas de carbonato de calcio

viven no basalto deste enorme monte submarino,

growing off the basalt of this massive undersea mountain,

and the dark sort of stuff, those are fossilized corals,

e o material escuro que se ve son corais fosilizados,

and we're going to talk a little more about those

dos que imos falar un pouco máis

as we travel back in time.

ao retrocedermos no tempo.

Para iso temos que fretar un barco de investigación.

To do that, we need to charter a research boat.

This is the James Cook, an ocean-class research vessel

Este é o James Cook, un buque oceánico de investigación

moored up in Tenerife.

atracado en Tenerife.

Looks beautiful, right?

Precioso, non si?

Great, if you're not a great mariner.

Fantástico, se un non é un gran mariño.

Sometimes it looks a little more like this.

En ocasións ten máis ben estoutro aspecto.

This is us trying to make sure that we don't lose precious samples.

Estes somos nós tratando de non perder mostras moi valiosas.

Everyone's scurrying around, and I get terribly seasick,

Todos á carreira, e eu maréome moitísimo,

so it's not always a lot of fun, but overall it is.

así que non sempre é divertido, aínda que en xeral, si.

So we've got to become a really good mapper to do this.

Para dedicarse a isto hai que ser moi bos cartógrafos.

You don't see that kind of spectacular coral abundance everywhere.

Non se atopa en calquera sitio esa espectacular abundancia de coral.

It is global and it is deep,

É global e está a gran profundidade,

but we need to really find the right places.

pero hai que buscala nos lugares adecuados.

Acabamos de ver un mapamundi, no que sinalamos

We just saw a global map, and overlaid was our cruise passage

from last year.

a travesía do ano pasado.

This was a seven-week cruise,

Foron sete semanas de viaxe,

and this is us, having made our own maps

e este é o mapa que nós fixemos

of about 75,000 square kilometers of the seafloor in seven weeks,

en sete semanas duns 75.000 quilómetros cadrados de fondo mariño,

but that's only a tiny fraction of the seafloor.

unha porción diminuta do fondo do mar.

Desprazámonos de oeste a leste,

We're traveling from west to east,

over part of the ocean that would look featureless on a big-scale map,

sobre unha zona da que un mapa a gran escala non mostraría nada,

but actually some of these mountains are as big as Everest.

aínda que algúns destes montes teñen o tamaño do Everest.

So with the maps that we make on board,

Cos mapas que facemos a bordo,

we get about 100-meter resolution,

obtemos unha resolución duns 100 metros,

enough to pick out areas to deploy our equipment,

o que abonda para decidir onde despregar o equipo,

but not enough to see very much.

pero non permite ver gran cousa.

To do that, we need to fly remotely-operated vehicles

Para facer isto precisamos dispositivos con control remoto

about five meters off the seafloor.

que se desprazan a uns cinco metros do fondo.

And if we do that, we can get maps that are one-meter resolution

Dese xeito podemos obter mapas cunha resolución dun metro

down thousands of meters.

a miles de metros de profundidade.

Here is a remotely-operated vehicle,

Este é un deses dispositivos remotos,

a research-grade vehicle.

un vehículo de máxima precisión.

Dispón de grandes focos na parte superior,

You can see an array of big lights on the top.

There are high-definition cameras, manipulator arms,

cámaras de alta definición, brazos robóticos,

and lots of little boxes and things to put your samples.

e múltiples caixiñas e cousas para gardar as mostras.

Esta era a nosa primeira inmersión nesta expedición concreta.

Here we are on our first dive of this particular cruise,

plunging down into the ocean.

Estámonos mergullando.

We go pretty fast to make sure the remotely operated vehicles

Imos rápido para que outros barcos non afecten

are not affected by any other ships.

aos nosos dispositivos con control remoto.

Imos descendendo,

And we go down,

and these are the kinds of things you see.

e estas son as cousas que se ven.

These are deep sea sponges, meter scale.

Estas son esponxas de augas profundas, a escala dun metro.

This is a swimming holothurian -- it's a small sea slug, basically.

Aquí vemos unha holoturia nadando -- en esencia, unha pequena lesma mariña.

Esta está a cámara lenta.

This is slowed down.

Most of the footage I'm showing you is speeded up,

A maioría das imaxes que amoso están aceleradas,

because all of this takes a lot of time.

porque todo isto leva moito tempo.

This is a beautiful holothurian as well.

Esta é outra fermosa holoturia.

And this animal you're going to see coming up was a big surprise.

E o animal que ides ver agora foi unha gran sorpresa.

I've never seen anything like this and it took us all a bit surprised.

Nunca vira algo así e colleunos a todos un pouco por sorpresa.

Levabamos unhas 15 horas traballando e estabamos algo sobreexcitados

This was after about 15 hours of work and we were all a bit trigger-happy,

e de repente este monstro pasou a rolos por diante de nós

and suddenly this giant sea monster started rolling past.

It's called a pyrosome or colonial tunicate, if you like.

Chámase pirosoma, ou tamén tunicado colonial.

This wasn't what we were looking for.

Non era isto o que buscabamos.

We were looking for corals, deep sea corals.

Nós andabamos á procura de corais de augas profundas.

You're going to see a picture of one in a moment.

Ides ver deseguida unha imaxe dun destes.

It's small, about five centimeters high.

É pequeno, duns cinco centímetros de alto.

Está composto de carbonato de calcio e vemos os seus tentáculos,

It's made of calcium carbonate, so you can see its tentacles there,

moving in the ocean currents.

que se moven coa corrente.

An organism like this probably lives for about a hundred years.

Un organismo coma este vive probablemente uns cen anos.

And as it grows, it takes in chemicals from the ocean.

Ao medrar, vai tomando substancias químicas do océano.

And the chemicals, or the amount of chemicals,

E a cantidade destas substancias

depende da temperatura, do pH

depends on the temperature; it depends on the pH,

it depends on the nutrients.

e dos nutrientes.

And if we can understand how these chemicals get into the skeleton,

Se logramos entender como se integran estas substancias no esqueleto,

we can then go back, collect fossil specimens,

podemos voltar, recoller espécimes fósiles

e reconstruír como era o océano no pasado.

and reconstruct what the ocean used to look like in the past.

And here you can see us collecting that coral with a vacuum system,

Aquí estamos recollendo ese coral cun sistema de baleiro,

and we put it into a sampling container.

para poñelo nun recipiente de mostras.

Debo engadir que o facemos con moitísimo coidado.

We can do this very carefully, I should add.

Some of these organisms live even longer.

Algúns destes organismos viven aínda máis tempo.

This is a black coral called Leiopathes, an image taken by my colleague,

Esta é unha foto dun coral negro chamado leiopathes.

Foi tomada por un colega, Brendan Roark, en Hawaii, a 500 metros de profundidade.

Brendan Roark, about 500 meters below Hawaii.

Four thousand years is a long time.

Catro mil anos é moito tempo.

If you take a branch from one of these corals and polish it up,

Se collemos unha póla dun destes corais e a pulimos,

isto son uns 100 microns.

this is about 100 microns across.

And Brendan took some analyses across this coral --

Brendan analizou varias seccións deste coral

you can see the marks --

--pódense ver as marcas--

e puido demostrar que en realidade se trata de franxas anuais,

and he's been able to show that these are actual annual bands,

de modo que mesmo a 500 metros de profundidade

so even at 500 meters deep in the ocean,

os corais poden rexistrar cambios estacionais.

corals can record seasonal changes,

which is pretty spectacular.

o cal é bastante espectacular.

But 4,000 years is not enough to get us back to our last glacial maximum.

Pero 4.000 anos non abonda para chegar ao punto máximo da última glaciación.

So what do we do?

Que facemos entón?

We go in for these fossil specimens.

Pois imos por estes espécimes fósiles.

This is what makes me really unpopular with my research team.

Por isto non lle caio moi ben ao meu equipo.

Cando nos mergullamos,

So going along,

there's giant sharks everywhere,

vemos moitos tiburóns xigantes,

there are pyrosomes, there are swimming holothurians,

pirosomas, holoturias nadando,

there's giant sponges,

esponxas xigantes,

but I make everyone go down to these dead fossil areas

pero eu obrígoos a baixar ás zonas mortas dos fósiles,

and spend ages kind of shoveling around on the seafloor.

onde pasan horas remexendo o fondo mariño.

And we pick up all these corals, bring them back, we sort them out.

Recollemos todos estes corais, subímolos e clasificámolos.

But each one of these is a different age,

Son de distintas idades, e

and if we can find out how old they are

se logramos determinar a de cada espécime

and then we can measure those chemical signals,

e medir eses sinais químicos,

iso axúdanos a saber

this helps us to find out

what's been going on in the ocean in the past.

que aconteceu no océano en épocas pasadas.

So on the left-hand image here,

Para obter a imaxe da esquerda,

I've taken a slice through a coral, polished it very carefully

collín unha sección de coral, pulina con moito coidado

and taken an optical image.

e fotografeina.

On the right-hand side,

Para a imaxe da dereita

we've taken that same piece of coral, put it in a nuclear reactor,

puxemos o mesmo anaco de coral nun reactor nuclear,

induced fission,

inducimos a fisión

and every time there's some decay,

e cada vez que hai desintegración

you can see that marked out in the coral,

queda unha marca no coral,

so we can see the uranium distribution.

e así podemos ver a distribución do uranio.

Why are we doing this?

Por que facemos isto?

Uranium is a very poorly regarded element,

O uranio é un elemento con moi mala reputación,

but I love it.

pero a min encántame.

A desintegración axúdanos a coñecer os ritmos e as datas

The decay helps us find out about the rates and dates

of what's going on in the ocean.

do que acontece no océano.

And if you remember from the beginning,

Se lembrades o que dixen ao comezo,

that's what we want to get at when we're thinking about climate.

iso é o que queremos saber cando pensamos no clima.

So we use a laser to analyze uranium

Así que aplicamos un láser a estes corais para analizar

and one of its daughter products, thorium, in these corals,

o uranio e un dos seus produtos fillos, o torio,

and that tells us exactly how old the fossils are.

e iso dinos con exactitude a idade dos fósiles.

This beautiful animation of the Southern Ocean

Esta fermosa animación do Océano Antártico

I'm just going to use illustrate how we're using these corals

servirame para ilustrar como empregamos estes corais

para obter información sobre o océano arcaico.

to get at some of the ancient ocean feedbacks.

You can see the density of the surface water

Podedes ver a densidade das augas superficiais

in this animation by Ryan Abernathey.

nesta imaxe animada creada por Ryan Abernathey.

It's just one year of data,

Mostra os datos dun só ano

but you can see how dynamic the Southern Ocean is.

pero pódese ver o dinámico que é o Océano Antártico.

The intense mixing, particularly the Drake Passage,

A intensa mestura, sobre todo o Paso de Drake,

which is shown by the box,

sinalado cun recadro,

is really one of the strongest currents in the world

é de feito unha das correntes máis fortes do mundo

a que flúe por aquí de oeste a leste.

coming through here, flowing from west to east.

It's very turbulently mixed,

A mestura é moi turbulenta,

because it's moving over those great big undersea mountains,

porque circula sobre eses enormes montes submarinos,

and this allows CO2 and heat to exchange with the atmosphere in and out.

o cal permite o intercambio de calor e CO2 coa atmosfera.

En esencia, os océanos respiran a través do Océano Antártico.

And essentially, the oceans are breathing through the Southern Ocean.

We've collected corals from back and forth across this Antarctic passage,

Recollimos corais ao longo de todo este paso antártico,

e descubrimos algo bastante sorprendente grazas á datación do uranio:

and we've found quite a surprising thing from my uranium dating:

the corals migrated from south to north

os corais migraron de sur a norte

during this transition from the glacial to the interglacial.

durante esta transición da glaciación ao período interglaciar.

Non sabemos ben por que,

We don't really know why,

but we think it's something to do with the food source

pero pensamos que ten que ver coas fontes de alimento

and maybe the oxygen in the water.

e se cadra coa concentración de osíxeno na auga.

Neste punto nos atopamos.

So here we are.

I'm going to illustrate what I think we've found about climate

Vou ilustrar o que penso que levamos descuberto sobre o clima

from those corals in the Southern Ocean.

grazas aos corais do Océano Antártico.

Subimos e baixamos montes submarinos. Recollimos pequenos fósiles de coral.

We went up and down sea mountains. We collected little fossil corals.

Así o represento eu.

This is my illustration of that.

We think back in the glacial,

Pensamos que durante a glaciación,

segundo as nosas análises dos corais,

from the analysis we've made in the corals,

that the deep part of the Southern Ocean was very rich in carbon,

a zona profunda do Océano Antártico era moi rica en carbono

and there was a low-density layer sitting on top.

e había unha capa de baixa densidade xusto encima

que impedía que o carbono saíse do océano.

That stops carbon dioxide coming out of the ocean.

We then found corals that are of an intermediate age,

Entón atopamos corais dunha idade intermedia

and they show us that the ocean mixed partway through that climate transition.

que demostran que o océano se mesturou no medio desa transición climática.

That allows carbon to come out of the deep ocean.

Iso permite ao carbono saír da zona máis profunda.

E se analizamos corais máis próximos á época moderna,

And then if we analyze corals closer to the modern day,

or indeed if we go down there today anyway

ou se baixamos hoxe mesmo alí

and measure the chemistry of the corals,

e medimos as propiedades químicas dos corais,

we see that we move to a position where carbon can exchange in and out.

vemos que pasamos a unha situación na que pode haber intercambio de carbono.

So this is the way we can use fossil corals

Este é o modo en que os corais fósiles

to help us learn about the environment.

nos axudan a aprender cousas sobre o medio.

So I want to leave you with this last slide.

Déixovos cunha última diapositiva.

It's just a still taken out of that first piece of footage that I showed you.

É unha imaxe fixa tirada da primeira gravación que mostrei.

This is a spectacular coral garden.

É un xardín de corais espectacular.

Non esperabamos atopar algo tan fermoso.

We didn't even expect to find things this beautiful.

It's thousands of meters deep.

Está a miles de metros de profundidade.

There are new species.

Hai especies novas.

It's just a beautiful place.

É simplemente un lugar fermoso.

There are fossils in amongst,

Tamén hai fósiles,

and now I've trained you to appreciate the fossil corals

e veño de prepararvos para valorar os fósiles de coral

that are down there.

que se atopan aló abaixo.

So next time you're lucky enough to fly over the ocean

A próxima vez que teñades a sorte de voar sobre o océano

or sail over the ocean,

ou de navegar por el,

lembrade que aló abaixo hai enormes montes submarinos

just think -- there are massive sea mountains down there

that nobody's ever seen before,

que ninguén viu aínda,

and there are beautiful corals.

e fermosos corais.

Grazas.

Thank you.

(Aplausos)

(Applause)