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

翻译人员: Hancheng Li 校对人员: Yinchun Rui

Well, I'm an ocean chemist.

我是一位海洋化学家。

I look at the chemistry of the ocean today.

我研究现代海洋的化学特性。

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

我也研究古代海洋的化学特性。

The way I look back in the past

我研究古代海洋的方式，

is by using the fossilized remains of deepwater corals.

是借助深海珊瑚的化石遗体。

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

各位可以在我的背后 看到这样一张图片。

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

这是在南极洲附近， 海平面以下的数千米处采集的。

so, very different than the kinds of corals

所以这些珊瑚跟其它种类非常不同，

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

比如说你去热带度假的时候 有幸见到的一些。

So I'm hoping that this talk will give you

我希望我的演讲能够为大家

a four-dimensional view of the ocean.

呈现一幅四维的海洋图像。

Two dimensions, such as this beautiful two-dimensional image

其中的两个维度， 正如这个漂亮的平面图，

of the sea surface temperature.

描述了海平面的温度。

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

这张照片是卫星拍摄的， 所以有着极高的空间分辨率。

The overall features are extremely easy to understand.

照片的大致内容是相当容易理解的。

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

赤道地区比较温暖， 因为接受的日照很多。

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

极地比较寒冷， 因为接受的日照较少。

And that allows big icecaps to build up on Antarctica

所以这就让南极洲的土地上 生成了巨大的冰盖，

and up in the Northern Hemisphere.

同样还有北半球的顶部。

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

如果你深潜入大海里， 或者只是让脚趾头碰到海水，

you know it gets colder as you go down,

你就会知道越深处越寒冷，

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

这主要是因为， 填充海底沟壑的深海海水

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

是来自寒冷的极地地区， 而那里的水密度更大。

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

如果我们让时光倒流两万年，

the earth looked very much different.

整个地球看上去非常不同。

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

我刚刚给你们看的是 其中一个巨大变化的漫画示意图，

you would have seen if you went back that long.

那个时代的景象就像这样。

The icecaps were much bigger.

冰盖要比现在大很多。

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

它们覆盖了大面积的陆地， 而且延展到各大洋。

Sea level was 120 meters lower.

海平面比现在低了120米。

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

二氧化碳[水平]比现在要低很多。

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

地球上的平均气温比现在 大概要低3到5摄氏度，

and much, much colder in the polar regions.

而且在极地地区要更加寒冷。

What I'm trying to understand,

我想要研究清楚的东西，

and what other colleagues of mine are trying to understand,

也是我的同事们想要弄明白的东西，

就是我们如何从那种极端寒冷的气候

is how we moved from that cold climate condition

to the warm climate condition that we enjoy today.

转变成现在我们所享受的 这种温暖气候的。

We know from ice core research

对冰芯的研究告诉我们，

that the transition from these cold conditions to warm conditions

从寒冷气候到温暖气候的转变 并不是非常平缓的，

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

你们可以通过太阳辐射的 缓慢增加中推测出来。

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

我们可以得出这种结论， 是因为如果你在冰盖上钻孔，

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

你可以发现按年份分层的冰， 就像这幅冰山的图片里。

You can see those blue-white layers.

你可以看到那些蓝白相间的条纹。

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

气体被封闭在这些冰芯里， 所以我们可以据此测定二氧化碳。

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

所以我们得知 以前的二氧化碳水平比现在要低。

and the chemistry of the ice also tells us about temperature

冰的化学组成同样可以告诉我们

极地地区的气温信息。

in the polar regions.

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

如果你从两万年前穿越到现代，

you see that temperature increased.

你会发现气温出现了增长。

It didn't increase smoothly.

它不是平缓地增长的。

Sometimes it increased very rapidly,

有时候气温上升得非常迅速，

then there was a plateau,

然后就稳定一段时间，

then it increased rapidly.

之后再次迅速上升。

It was different in the two polar regions,

气温在两极地区有些差异，

and CO2 also increased in jumps.

而且二氧化碳水平 也以这种跳跃方式增长。

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

于是我们可以确定， 海洋与这些变化有着密切联系。

The ocean stores huge amounts of carbon,

海洋里储存着大量的碳元素，

about 60 times more than is in the atmosphere.

比大气中的储量多了大约60倍。

It also acts to transport heat across the equator,

海洋还有的作用， 就是跨赤道地区输送热量，

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

而且海洋里富含养分， 还提供了极高的初级产能。

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

如果我们想要研究 深海世界里发生了什么，

we really need to get down there,

我们真的需要潜入其中，

see what's there

看看那里有什么，

and start to explore.

并且开始努力探索。

This is some spectacular footage coming from a seamount

这是采自海底山峰的 一些精彩镜头，

about a kilometer deep in international waters

这个山峰位于赤道地区的公海， 而且远离大陆，

in the equatorial Atlantic, far from land.

大概在大西洋底1,000米深处。

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

你们是最先欣赏到 这个地区的海底的一群人，

along with my research team.

跟我的研究团队差不多。

You're probably seeing new species.

你们可能看到的是一些新物种。

We don't know.

然而我们并不了解。

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

你得采集很多样本， 然后做非常繁琐的生物学分类。

You can see beautiful bubblegum corals.

你可以看到这些美丽的 泡泡糖珊瑚。

There are brittle stars growing on these corals.

柔软的海星长在这些珊瑚上。

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

它们看起来就像珊瑚上 延伸出的触手一样。

There are corals made of different forms of calcium carbonate

这些珊瑚由不同形式的碳酸钙组成，

growing off the basalt of this massive undersea mountain,

在这个巨大的海底山峰的 玄武岩上茁壮生长，

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

那些颜色很黑的东西， 就是变成化石的珊瑚，

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

让我们回到过去，

更仔细聊聊这些珊瑚的故事。

as we travel back in time.

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

要做时光旅行， 我们得租一条考察船，

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

这是詹姆斯·库克号， 一艘大洋级的调查船，

moored up in Tenerife.

停泊在特纳里夫港口。

Looks beautiful, right?

看上去很棒，对吧？

Great, if you're not a great mariner.

如果你不是个很好的海员， 你会觉得不错的。

Sometimes it looks a little more like this.

但是有时她看起来更像这样。

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

我们正在努力保证 珍贵的样品不丢失。

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

每个人都手忙脚乱， 然后我也严重晕船，

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

所以说这不全是有趣的经历， 但是总体还是不错的。

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

我们必须要成为很好的测绘师 才能做这个工作。

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

你不可能在处处都找到 如此丰富的珊瑚储量。

It is global and it is deep,

我们得走遍世界、潜入深海寻找，

but we need to really find the right places.

但是我们必须得找到正确的地方。

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

我们刚刚看到一个世界地图， 上面重叠着我们去年的航线。

from last year.

This was a seven-week cruise,

那是一个为期七周的航程，

and this is us, having made our own maps

这就是我们自己做的地图，

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

在七周时间里，我们描绘了 大约75,000平方公里的海底地图，

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

但那也只是整个海底的微小部分。

We're traveling from west to east,

我们自西向东航行，

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

穿过的一些海域， 在世界地图上没有任何特征可言，

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

但是这里的一些山峰 其实可以跟珠穆朗玛峰相提并论。

So with the maps that we make on board,

我们在船上制作的地图，

we get about 100-meter resolution,

大概有100米左右的分辨率，

enough to pick out areas to deploy our equipment,

这已经足够让我们 选定地址放置测绘仪器，

but not enough to see very much.

但是想要看得更清楚就不是很够。

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

为了使图像更清晰， 我们要操纵遥控的深潜器，

about five meters off the seafloor.

到距离海底5米左右的深处。

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

如果我们这么做，我们可以得到 海平面以下数千米处

down thousands of meters.

分辨率小至1米的高清图像。

Here is a remotely-operated vehicle,

这就是一台遥控深潜器，

a research-grade vehicle.

科研级别的深潜器。

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

你可以在它顶部看到一排大灯。

There are high-definition cameras, manipulator arms,

上面还有高清摄影机、操纵臂，

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

还有各种小盒子、小零件 来收集海底样本。

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

这是我们航程的第一次深潜，

plunging down into the ocean.

机器潜到大洋深处。

We go pretty fast to make sure the remotely operated vehicles

我们让它尽快下潜，

使它不会受其它过往船只的影响。

are not affected by any other ships.

And we go down,

我们不断下潜，

and these are the kinds of things you see.

这就是你们可以看到的东西。

These are deep sea sponges, meter scale.

这些是大小达到数米的深海海绵。

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

这是个游动的海参—— 其实是一个小的海底蛞蝓。

This is slowed down.

这些是慢镜头。

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

我展示的大部分视频资料 都是加速播放的，

because all of this takes a lot of time.

因为这些过程都耗时很长。

This is a beautiful holothurian as well.

这也是一个漂亮的海参。

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

接下来你们看到的这个动物 是一个很大的惊喜。

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

我从来没见过任何类似的东西， 这让我们所有人都震惊了。

我们已经连续工作了15个小时， 都累得很不耐烦了，

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

突然这个巨大的海怪 缓缓从我们旁边游过。

and suddenly this giant sea monster started rolling past.

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

它叫做“火体虫”， 或者说是一种寄生性尾索动物。

This wasn't what we were looking for.

这可不是我们要找的东西。

We were looking for corals, deep sea corals.

我们在搜寻珊瑚， 深海里的珊瑚。

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

你们过一会儿就会 看到一张珊瑚的照片。

It's small, about five centimeters high.

它很小，只有5厘米高。

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

它是由碳酸钙构成的， 你们可以看到它的触手，

moving in the ocean currents.

在洋流之中摆动。

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

像这样的有机体 一般可以存活100年。

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

在它生长过程中， 它从海洋中吸收化学成分。

And the chemicals, or the amount of chemicals,

这些化学成分， 或是说化学成分的量，

depends on the temperature; it depends on the pH,

取决于海水温度，还有pH值，

it depends on the nutrients.

以及水中的养分。

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

如果我们可以理解 这些化学成分如何进入生物骨架，

we can then go back, collect fossil specimens,

我们就可以采集样本、回溯历史，

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

重现古代海洋的图景。

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

现在你们可以看到我们在用 抽真空系统收集那个珊瑚样本，

and we put it into a sampling container.

然后把样本放在容器里。

We can do this very carefully, I should add.

我应该补充一下， 我们可以做得非常仔细。

Some of these organisms live even longer.

这类有机体有些可以活得更长。

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

这是一种名叫“黑树”的黑角珊瑚， 在夏威夷海域500米深处找到，

Brendan Roark, about 500 meters below Hawaii.

照片是由我的同事 布兰登·洛克拍摄的。

Four thousand years is a long time.

四千年可是很长的时间啊。

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

如果你从这种珊瑚中 摘取一段枝条，然后把它打磨，

this is about 100 microns across.

这张图横向大约有100微米宽。

And Brendan took some analyses across this coral --

布兰登对这个珊瑚做了横切分析，

you can see the marks --

你们可以看到横向的标记，

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

他由此证明了这其实是珊瑚的年轮，

so even at 500 meters deep in the ocean,

所以说即使在 海平面以下500米深处，

corals can record seasonal changes,

珊瑚可以记录季节的更替，

which is pretty spectacular.

这其实是挺惊人的。

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

然而四千年不足以让我们 回到最后一个冰川极盛期。

So what do we do?

那么我们怎么办呢？

We go in for these fossil specimens.

我们潜入海中寻找化石样本。

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

其实这就是为什么 我在研究团队里特别不受人欢迎。

So going along,

所以潜到海底，

there's giant sharks everywhere,

到处都是巨大的鲨鱼，

there are pyrosomes, there are swimming holothurians,

还有火体虫、游动的海蛞蝓，

there's giant sponges,

以及巨大的海绵，

but I make everyone go down to these dead fossil areas

但是我要求每个人都 潜到这死气沉沉的化石区，

and spend ages kind of shoveling around on the seafloor.

然后花很长的时间 在海底铲来铲去。

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

我们拾取所有的珊瑚样本， 把它们带回来，然后做分类。

But each one of these is a different age,

但是每一个样本都来自不同的时代，

and if we can find out how old they are

如果我们可以知道它们有多古老，

and then we can measure those chemical signals,

然后我们去测定 其中的化学信号，

this helps us to find out

这就可以帮助我们

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

研究出古代海洋中 发生了怎样的事。

So on the left-hand image here,

请看左侧的照片，

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

我对珊瑚做了一份纵切片， 很仔细地打磨，

and taken an optical image.

之后拍摄了光学影像。

On the right-hand side,

在右侧的照片中，

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

我们提取了同一片珊瑚， 将它放进核反应堆，

induced fission,

诱发核裂变反应，

and every time there's some decay,

每一次都会产生一些衰减，

you can see that marked out in the coral,

你可以在珊瑚中看到一些标记，

so we can see the uranium distribution.

我们可以据此判断 铀元素的分布情况。

Why are we doing this?

我们为什么要这么做呢？

Uranium is a very poorly regarded element,

铀是一种很不被重视的元素，

but I love it.

但是我非常喜欢它。

The decay helps us find out about the rates and dates

这种衰减帮助我们研究出

海洋中何时发生了何事， 某种成分有多大的量。

of what's going on in the ocean.

And if you remember from the beginning,

如果你们还记得我开头所讲的，

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

这就是我们思考气候问题时 想要进一步研究的东西。

So we use a laser to analyze uranium

所以我们用激光去分析铀元素，

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

以及珊瑚中所含的， 铀的副产物钍元素，

and that tells us exactly how old the fossils are.

由此我们得知这些化石的精确年龄。

This beautiful animation of the Southern Ocean

这个漂亮的南极洋动画，

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

展现了我们如何利用这些珊瑚

to get at some of the ancient ocean feedbacks.

来提取古代海洋的反馈信息。

You can see the density of the surface water

这个由莱恩·阿伯纳西制作的动画中，

in this animation by Ryan Abernathey.

你们可以看到表面海水的密度分布。

It's just one year of data,

这只是一年的数据，

but you can see how dynamic the Southern Ocean is.

但是各位已经可以看出 南极洋非常动态的变化。

The intense mixing, particularly the Drake Passage,

尤其是方框中的德雷克海峡，

which is shown by the box,

这里洋流交汇非常强烈，

is really one of the strongest currents in the world

其实是世界上 最强的洋流之一。

coming through here, flowing from west to east.

洋流从西到东穿过海峡。

It's very turbulently mixed,

洋流在此处汹涌地交汇，

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

因为它经过了那些 巨大的海底山峰，

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

这就让二氧化碳和热量 与大气进行交换。

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

本质上，海洋系统 通过南极洋进行“呼吸”作用。

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

我们在这个南极的海峡 来回穿行，采集珊瑚样本，

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

从我的铀元素年代测定结果， 我们得到了很惊人的结论：

the corals migrated from south to north

从冰期到间冰期的过渡期，

during this transition from the glacial to the interglacial.

这些珊瑚从南方迁移到了北方。

We don't really know why,

我们并不知道为什么，

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

但是我们认为这与 食物来源有一些关联，

and maybe the oxygen in the water.

或者是海水中的氧气含量。

So here we are.

所以讲到这儿，

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

我接下来要展示， 我们从南极洋的珊瑚中

得出的有关气候的结论。

from those corals in the Southern Ocean.

我们在海底山脉中游走， 我们采集了细小的珊瑚化石。

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

这是我的图解。

This is my illustration of that.

We think back in the glacial,

在分析了珊瑚之后，

from the analysis we've made in the corals,

我们认为，在冰川期时，

南极洋的深处碳元素非常丰富，

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

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

并且一层低密度海水浮在大洋表面。

That stops carbon dioxide coming out of the ocean.

这就阻止了二氧化碳从海洋中逸出。

We then found corals that are of an intermediate age,

我们之后发现了一些 中等年龄的珊瑚，

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

它们告诉我们，洋流的激烈交汇 发生在气候过渡期的中段。

That allows carbon to come out of the deep ocean.

这让深海中的碳元素得以逸出。

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

那么如果我们研究 更接近现代的珊瑚，

or indeed if we go down there today anyway

或者我们干脆马上就潜到海里，

and measure the chemistry of the corals,

然后研究珊瑚的化学成分，

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

我们可以看到现在是 二氧化碳进行进出交换的时代。

So this is the way we can use fossil corals

所以这就是我们利用珊瑚化石

to help us learn about the environment.

来研究环境变化的方法。

So I want to leave you with this last slide.

那么我给大家展示最后一张幻灯片。

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

这是从最开始我播放的视频中 截取的一张图片。

This is a spectacular coral garden.

这是一个异常美丽的珊瑚花园。

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

我们根本没有想象到 会发现如此之美的东西。

It's thousands of meters deep.

这里有数千米深。

There are new species.

这里有全新的物种。

It's just a beautiful place.

这就是一个美丽的圣地。

There are fossils in amongst,

这其中有很多化石，

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

现在我教会大家 去欣赏这些化石珊瑚，

that are down there.

沉睡在海底深处。

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

所以说下一次当你有幸飞过大洋时，

or sail over the ocean,

或者是航行在海洋之上，

just think -- there are massive sea mountains down there

请各位记得—— 海底世界有崇山峻岭，

that nobody's ever seen before,

无人领略过它的壮美，

and there are beautiful corals.

海底世界还有美丽的珊瑚。

Thank you.

谢谢各位。

(Applause)

（掌声）