There is only one planet in the universe,as far as we know,
据我们所知,宇宙中只有一颗行星,
where there is life.
哪里有生命
The Earth.
地球
Our home.
我们的家
The perfect planet.
完美的星球
Life here is only possible
这里的生活是唯一可能的
because of a unique balance of natural forces.
因为自然力的独特平衡
Energy from the sun powers the living world.
来自太阳的能量为生活世界提供能量
Weather systems transport fresh water around the globe.
天气系统将淡水输送到全球各地
And powerful ocean currents
强大的洋流
circulate life's essential nutrients.
循环生命的基本营养
This series will reveal how these global forces have worked together
本系列将揭示这些全球力量是如何协同工作的
to create our planet's fragile life-support system.
创造我们星球脆弱的生命维持系统
One of these forces is so important
其中一种力量非常重要
that life would never have even started without it.
如果没有它,生活就不会开始
Across the surface of our planet,
穿过地球表面,
there are over 1,500 active volcanoes.
有1500多座活火山
This is the most active - Kilauea in Hawaii.
这是夏威夷最活跃的基拉韦厄
Here,magma - liquid rock from the planet's hot interior -
在这里,岩浆-液态岩石来自行星炽热的内部-
bursts out through fractures in the Earth's crust,
从地壳的裂缝中爆发出来,
and it's been flowing for months.
已经流了好几个月了
Nothing can stand in the lava's way.
没有什么能阻挡熔岩
Volcanoes are certainly destructive.
火山当然具有破坏性
But without these powerful underground forces,
但是没有这些强大的地下力量,
there would be no breathable atmosphere.
没有可呼吸的空气
No oceans.
没有海洋
No land.
没有土地
No life.
没有生命
We can't control volcanoes,
我们无法控制火山,
but they're vital for all living things on Planet Earth.
但它们对地球上所有生物都至关重要
This is Ol Doinyo Lengai in Tanzania.
我是坦桑尼亚的Ol Doinyo Lengai
It's one of Africa's most active volcanoes,
它是非洲最活跃的火山之一,
and has erupted over 15 times in the last 100 years.
在过去的100年里已经爆发了15次
On its northern flank lies Lake Natron,
它的北侧是纳特龙湖,
400 square miles in extent,
面♥积♥400平方英里,
and one of the world's most corrosive bodies of water.
世界上最具腐蚀性的水体之一
The water wells up from deep below,
从地下深处涌出的水井,
carrying such a concentration of chemicals that it can burn skin.
携带如此浓度的化学物质会灼伤皮肤
But one animal thrives here.
但有一种动物在这里繁衍生息
Volcano birds.
火山鸟
Nearly two million lesser flamingos live in East Africa
近200万只小火烈鸟生活在东非
and all of them come here to breed.
它们都来这里繁殖
But they can only nest here when the lake's level
但它们只能在湖水平的时候在这里筑巢
drops so far that in the centre,its bed is exposed.
下降到如此之远,以至于在中心,它的床是暴露的
And that rare moment is now.
那难得的时刻就是现在
How they know when the conditions are right is a mystery,
他们怎么知道什么时候条件合适是个谜,
but some have flown thousands of miles to be here.
但有些人已经飞了几千英里来到这里
The flamingos head for the middle of the lake,
火烈鸟向湖中♥央♥飞去,
where the intense evaporation has created islands of salt.
剧烈的蒸发形成了盐岛
It's here that the birds build their nests,
鸟儿在这里筑巢,
over three miles from the lake's edge
离湖边三英里多
and safe from land predators,which are unable to cross
远离无法穿越的陆地掠食者
the surrounding moat of caustic soda.
周围的苛性钠护城河
The single egg is laid on a mount of hardened salt
一个蛋产在一堆坚硬的盐上
built by the adults,
由成年人建造,
its height an insurance against a sudden rise in water level
它的高度是防止水位突然上升的保险
which often happens on Lake Natron.
这经常发生在纳特龙湖
As the centre dries and enlarges,
随着中心变干变大,
more and more flamingos arrive to nest on it.
越来越多的火烈鸟来到这里筑巢
In good years,such as now,
在好年头,比如现在,
as many as half a million pairs breed here.
多达50万对在这里繁殖
After 28 days of incubation,
孵育28天后,
a chick emerges into Natron's harsh glare.
一只小鸡出现在纳特龙刺眼的目光中
Here,temperatures can rise to 55 degrees Celsius.
在这里,温度可以上升到55摄氏度
Mother's wing,however,can serve as a sun shield.
然而,母亲的翅膀可以起到防晒的作用
The chick is fed a rich liquid
小鸡被喂了大量的液体
made of the lake's barely digested algae
由湖中几乎不能消化的藻类组成
and traces of its parent's blood.
还有它父母的血迹
After a few days,the chick is strong enough to stretch its legs.
几天后,小鸡就强壮到可以伸展腿了
It then joins a growing creche,made up of chicks of different ages.
然后它加入了一个成长中的托儿所,由不同年龄的小鸡组成
Soon,the need for fresh water will force the infant birds
很快,对淡水的需求将迫使幼鸟
to trek to springs on the lake's edge.
长途跋涉到湖边的泉水
A journey they have to make on foot,
他们必须徒步旅行,
as their flight feathers have yet to develop.
因为它们的飞行羽毛还没有发育
Every day,the adults fly to these springs to feed.
每天,成虫都飞到这些泉水里去觅食
Here,on the lake's margins,they collect algae that flourish
在这里,在湖边,他们收集藻类繁盛
in the volcanic water -
在火山水中-
vital food for the flamingos.
火烈鸟的重要食物
It's the algae that turn the flamingos' feathers pink.
是藻类使火烈鸟的羽毛变成粉红色
It even colours their eyes.
甚至给他们的眼睛涂上颜色
The adults spend most of their day at the springs,
成年人一天的大部分时间都呆在泉水里,
and now their chicks are going to join them there.
现在他们的小鸡要加入他们的行列了
No-one wants to get left behind.
没有人想被落在后面
It's a three-mile march over razor-sharp flakes of soda
在锋利的苏打水上行进了三英里
and sticky,caustic mud.
还有粘稠的腐蚀性泥浆
A life-threatening trial,especially for the youngest chicks.
危及生命的审判,尤指对幼雏的审判
The groups merge into one giant creche.
这些团体合并成一个巨大的托儿所
For some,the challenges are just too great.
对一些人来说,挑战太大了
Exhaustion overcomes the weakest.
精疲力竭战胜最虚弱的人
And now,there is yet another threat.
现在,还有另一个威胁
Marabou storks.
马拉布鹳
They have long legs like a flamingo,
它们的腿长得像火烈鸟,
but a beak like a Roman sword.
而是一把像罗马剑一样的喙
And they are patient,
他们很有耐心,
waiting for an easy target.
等待一个容易的目标
Their very presence creates panic among the chicks.
它们的出现引起了小鸡们的恐慌
The smallest avoid being trampled underfoot
最小的避免被踩在脚下
by travelling on the outside of the group.
在团队之外旅行
But that exposes them to attack.
但这会让他们受到攻击
Their only defence is to run.
他们唯一的防御就是逃跑
But you have little chance
但你几乎没有机会
when you're barely ankle-high to your pursuer.
当你和你的追求者只有脚踝高的时候
Stragglers will almost certainly be taken.
掉队者几乎肯定会被带走
But there comes a point when every stork has had its fill.
但总有一天,每只鹳都会吃饱的
This little chick is very lucky.
这只小鸡很幸运
At last,the youngsters reach the freshwater springs
最后,孩子们到达了淡水泉
at the lake's margin to rejoin their parents.
在湖边与父母团聚
Almost unbelievably,each chick has a unique call
几乎难以置信的是,每个小鸡都有一个独特的叫声
that its parent can recognise.
它的父母能认出
It's not just lesser flamingos that depend on volcanoes.
不仅仅是较小的火烈鸟依赖火山
Ultimately,so do all living things.
最终,所有生物也是如此
Over 80% of the Earth's surface
地球表面的80%以上
is the result of magma bursting up from the molten interior.
是岩浆从熔融的内部喷出的结果
The process started four billion years ago
这个过程始于40亿年前
and it still continues today.
今天仍在继续
When lava cools,it solidifies into rock,
当熔岩冷却时,会凝固成岩石,
and eventually weathers into land that can support life.
最终风化成能维持生命的陆地
All the Galapagos Islands in the Pacific are volcanic,
太平洋上所有的加拉帕戈斯群岛都是火山,
and Fernandina is the youngest of them.
费尔南迪娜是其中最小的
And still growing.
而且还在增长
At its centre,a volcanic crater four miles wide
在它的中心,一个四英里宽的火山口
and over 800 metres deep.
深度超过800米
It seems dormant,but it was erupting only two weeks ago.
它似乎处于休眠状态,但两周前才喷发
Even so,there are some who depend on the heat from this volcano.
即便如此,仍有一些人依赖这座火山的热量
A female land iguana,heavy with eggs,approaches the crater's rim.
一只雌性陆地鬣蜥,带着厚厚的卵,靠近陨石坑的边缘
It took her ten days to climb up here,
她花了十天时间爬到这里,
but the toughest part of her journey is still ahead.
但她最艰难的旅程还在前方
She's going to descend into the crater itself.
她会自己掉到陨石坑里
Frequent tremors make the crater walls unstable.
频繁的震动使火山口壁不稳定
More people have travelled in space
更多的人在太空旅行