What's below the tip of the iceberg? - Camille Seaman

翻译人员: Gabriella Hu 校对人员: Zongzhen Yang

Have you ever heard the term,

你们有没有听说过这个成语

"tip of the iceberg"?

“冰山一角”？

You know that icebergs are mostly underwater,

你知道冰山大部分都在水下，

their immense bulk hidden beneath the water.

它巨大的体积都隐藏在水平面下

But why is that so?

但是为什么呢？

Well, the density of pure ice

因为纯冰的密度

is less than that of sea water.

小于海水的密度

Usually only 1/9 of the volume of an iceberg

通常的冰山只有九分之一的体积

is above the water.

是露出水面的

The shape of the underwater portion

水下那一部分的形状

is difficult to discern

很难通过

by looking at the above-surface portion.

观察水平面上的冰山辨别

This has led to the expression,

这演变成了一个成语：

"tip of the iceberg."

”冰山一角“

Here are some thing you might not know

你们可能对冰山不是

about the icy islands.

那么地了解

The life of an iceberg

一个冰山的形成

begins many thousands of years

发生在几千年前

before it reaches the ocean.

在它达到海洋之前

Unlike sea ice or pack ice,

与海冰和浮冰不同的是，

which form when the ocean freezes,

它们不是在海洋冻结的时候形成的，

glaciers are made of fresh water.

冰川里面是淡水

For thousands of years,

千百年来，

these glaciers build layer upon layer of ice,

这些冰川建立在一层层的冰上面，

constantly compressing,

不停地压缩，

moving,

移动，

adding snow,

添加雪，

compressing,

压缩，

and moving again

再次移动

as they inch along like a frozen river.

慢慢地像一条冰冻的河一样移动

It is the force of gravity

在重力的作用下

that pulls them towards the sea,

它们缓缓移向海洋，

where a glacier may calve off to become an iceberg

然后冰川可能会崩解，变成了冰山

or continue to spread up as an ice shelf

或者继续积聚一层层的冰变成冰架

or an ice tongue.

或者冰舌

Once an iceberg breaks away

当一个冰山脱离了

from the glacier or ice shelf,

冰川或者冰架的时候，

it will usually live for three to six years,

它通常会3到6年保持不变，

floating around, carried by the currents

到处浮动，随着水流

and tidal movements of the ocean.

和海洋的浪潮漂移

As it floats along,

在它漂移的过程中，

it is battered by waves,

它被浪花击打，

melts,

融化，

and smashes into land

撞到陆地

and sometimes other icebergs.

有时和别的冰山撞击

Some icebergs are so unstable

有些冰山尤其不稳定，

that they have more dramatic ends,

它们的结局更具有戏剧性

heaving up,

collapsing,

升沉起来，

倒塌，

and sometimes even exploding.

有时甚至爆炸

And as they fall apart,

当它们四分五裂的时候，

many icebergs make all sorts of strange sounds.

很多冰山发出各种奇怪的声音

When a piece of iceberg melts,

当冰山融化的时候，

it makes a fizzing sound,

它会发出嘶嘶声，

called Bergie Seltzer.

叫做Bergie Seltzer

This sound is made when the water-ice interface

当水冰界面触及被困在冰里的

reaches compressed air bubbles trapped in the ice.

压缩的泡泡时发出的声音

As this happens, each bubble bursts,

当这发生时，泡泡会爆掉，

making a popping sound.

发出啪啪的响声

There are six official size classifications for icebergs.

冰山的有六种大小分类

The smallest icebergs are called growlers.

最小的冰山叫做碎冰山

They can be up the size of your car

它们大概是你的车的大小

and are very dangerous for ships and boats

对船只是一个隐患

because usually they sit just at the waterline

因为它们通常就在吃水线的高度

where they are not easy to spot.

不容易被发现

Next are the bergy bits

接下来是“似冰山”的冰山

- yes, that is their scientific name -

是的，这是它们的学名，

which can be up to the size of your home.

大小和房子差不多，

The other four sizes are small,

其余的四个体积大小是：小号，

medium,

large,

中号，

大号，

and very large.

和超大号

So just how big is a very large iceberg?

超大号的冰山到底有多大呢？

Officially, any iceberg looming larger

准确地来说，任何

than 270 feet high above sea level

海平面上高于270英尺，

and 670 feet long

670英尺长的冰山

is considered very large.

都是超级大的

That's 27 stories of looming, blue ice.

那就是27层楼高的若隐若现的蓝色的冰

And how do icebergs get that blue color anyways?

为什么冰山是蓝色的呢？

When snow on the glacier

当冰川上的雪

is compressed over many hundreds of years,

通过几百年的压缩，

the weight of the snow

雪的重量

forces the air bubbles out of the ice,

把泡泡挤出来，

creating pure ice with very little air trapped inside.

使冰中含有极少量的空气

This compression is seen

这种压缩在

when the glacier calves,

冰川分裂的时候可以看到，

creating a blue iceberg.

使冰川变成蓝色的

An iceberg that has not experienced

一个没有经过这种压缩

as much compression

的冰山里面

and has a large amount of air and surface edges

仍然有大量的空气和表面边缘

reflects light as white.

反射光为白色

Although they form in far northern or southern areas,

尽管它们是在远北或远南地区形成的，

icebergs can float thousands of miles.

冰山可以漂浮数千英里

An iceberg from the Arctic floated

一个北极的冰山可以漂浮

as far south as Bermuda.

南至百慕大

Antarctic icebergs are mostly trapped

南极的冰山大多数都被困在

in the Circumpolar Current,

南极环流，

never giving them a chance to float north.

基本不可能往北边漂

However, they have been known to interrupt

但是，它们之前阻碍过

shipping lanes between Australia,

澳大利亚，南美，

South America,

和南非之间的

and South Africa.

航运通道

For all their travelling,

冰山漂泊万里，

many people think

很多人依旧认为

that these slabs of ice are barren of life,

这些冰块毫无声息，

but these seemingly sterile ice slabs

但是这些看似荒芜的“冰块”

also harbor their own complex ecosystems

也怀有它们自己复杂的生态系统

and they shape the ecosystems

冰山边漂移，

that they pass through.

边塑造生态系统

They become mobile, floating ecosystems.

它们变成了移动式，漂浮的生态系统

Even in the coldest seas,

即使在最冷的海域，

icebergs are always melting,

冰山一直在融化，

at least a little bit.

一点一点地融化

This melting has a major impact

它们的融化对周边的海水

on the ocean around an iceberg.

有极大的影响

The fresh water from the berg

冰山里的淡水

creates a pool of fresh water

创造了一片淡水

that can extend a nautical mile away from the iceberg.

延伸到冰山周边一海里

This water is colder than the surrounding sea water,

这些水比周边的海水冷，

and the temperature variation creates thermal currents

温度差异在冰山附近

in the vicinity of the iceberg.

产生热流

Life thrives on and around an iceberg.

冰山上和冰山周边都充满了生机

Young icefish hide in small ice holes to avoid predators,

小的银鱼会藏在小冰孔里面躲避捕食者，

while a variety of invertebrates,

各种各样的无脊椎动物，

like jellyfish and siphonophores,

比如海蜇和管水母，

congregate in the area.

都聚集在这片地区

Many of them come to feed on krill,

很多生物来这里吃磷虾，

tiny shrimp-like creatures.

小型虾类动物

Snow petrels nest on the icebergs

雪海燕在冰山上筑巢

and feed on the sea life nearby.

捕食周边的海洋生物，

Whales and seals and penguins seem to like them too.

鲸鱼，海豹和企鹅似乎也很喜欢冰山

And even now that you know all this,

你们现在了解了那么多，

we're still at the tip of the iceberg.

我们仍然在冰山一角

There are all sorts of things

还有很多关于冰山的知识

we don't know about icebergs.

我们还一概不知的

Perhaps you'll be the one to see a little deeper.

也许你能看得更深