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

譯者: Regina Chu 審譯者: Hao Li

Have you ever heard the term,

你有聽過這個名詞

"tip of the iceberg"?

「冰山一角」嗎？

You know that icebergs are mostly underwater,

你知道冰山大多在水下

their immense bulk hidden beneath the water.

其巨大的主體藏在水面下

But why is that so?

但你有想過為什麼嗎？

Well, the density of pure ice

這麼說吧，純冰的密度

is less than that of sea water.

低於海水的密度

Usually only 1/9 of the volume of an iceberg

通常冰山只有 1/9 的體積

is above the water.

是在水上

The shape of the underwater portion

而其水下部分的形狀

is difficult to discern

很難靠著

by looking at the above-surface portion.

水面上的部分來判斷

This has led to the expression,

這也就是俗話

"tip of the iceberg."

「冰山一角」的由來

Here are some thing you might not know

現在我要講一些大家可能不知道

about the icy islands.

有關這些「冰島」的事

The life of an iceberg

冰山的一生

begins many thousands of years

在它到達海洋前數千年

before it reaches the ocean.

就開始了

Unlike sea ice or pack ice,

不像海冰或是浮冰

which form when the ocean freezes,

是海水凍結後形成

glaciers are made of fresh water.

冰河則是由淡水形成

For thousands of years,

數千年來

these glaciers build layer upon layer of ice,

一層又一層的冰堆疊成冰河

constantly compressing,

再不斷地擠壓

moving,

移動

adding snow,

加上新的雪

compressing,

再擠壓

and moving again

然後又再移動

as they inch along like a frozen river.

一吋吋向前移動像冰凍的河般

It is the force of gravity

因為重力

that pulls them towards the sea,

使得冰河往海移動

where a glacier may calve off to become an iceberg

在海裡冰河崩解成一塊冰山

or continue to spread up as an ice shelf

或繼續向前延伸成冰棚

or an ice tongue.

或冰舌

Once an iceberg breaks away

一但冰山從

from the glacier or ice shelf,

冰河或冰棚上崩離

it will usually live for three to six years,

它通常會持續存留三到六年

floating around, carried by the currents

四處漂移，隨著洋流

and tidal movements of the ocean.

及海洋的潮汐移動

As it floats along,

在它漂浮移動時

it is battered by waves,

它被海浪沖擊

melts,

融化

and smashes into land

撞到陸地

and sometimes other icebergs.

或其它冰山，變成粉碎

Some icebergs are so unstable

有些冰山非常不穩定

that they have more dramatic ends,

使得它們的結局非常戲劇化

heaving up,

collapsing,

它們隆起

崩解

and sometimes even exploding.

有時候甚至爆掉了

And as they fall apart,

而當它們分崩離析時

many icebergs make all sorts of strange sounds.

許多冰山還會製造各種奇怪的聲音

When a piece of iceberg melts,

當一塊冰山融化時

it makes a fizzing sound,

它發出嘶嘶聲

called Bergie Seltzer.

稱做「暴走的氣泡」 （Bergie: 南非俗語，遊民）

This sound is made when the water-ice interface

這種聲音來自水與冰的介面

reaches compressed air bubbles trapped in the ice.

碰到被壓縮、困在冰裡的氣泡

As this happens, each bubble bursts,

這種情況發生時，每個氣泡破掉

making a popping sound.

發生啪啪的聲音

There are six official size classifications for icebergs.

冰山有六種正式的大小分類

The smallest icebergs are called growlers.

最小的冰山稱為「咆哮」極小冰山

They can be up the size of your car

它們可以是你的車子大小

and are very dangerous for ships and boats

對於大船小船都非常危險

because usually they sit just at the waterline

因為它們通常在水線上沉浮

where they are not easy to spot.

很不容易被發現

Next are the bergy bits

次小的稱為較小冰山

- yes, that is their scientific name -

是的，這就是它們的學名

which can be up to the size of your home.

可以是你的家的大小

The other four sizes are small,

其他四種尺寸則為小

medium,

large,

中

大

and very large.

及特大

So just how big is a very large iceberg?

所以到底特大的冰山有多大呢？

Officially, any iceberg looming larger

正式來說，任何赫然聳現的冰山

than 270 feet high above sea level

在海平面以上部分超過 82 公尺高

and 670 feet long

及 204 公尺長

is considered very large.

就被認為是特大

That's 27 stories of looming, blue ice.

那是 27 層樓高的朦朧藍色大冰塊

And how do icebergs get that blue color anyways?

那到底冰山是怎麼變成藍色的？

When snow on the glacier

當冰河上的雪

is compressed over many hundreds of years,

被壓縮超過數百年

the weight of the snow

雪的重量

forces the air bubbles out of the ice,

迫使氣泡脫出冰層

creating pure ice with very little air trapped inside.

產生幾乎沒有空氣困在其中的純冰

This compression is seen

這種壓縮可在

when the glacier calves,

冰河崩解時看見

creating a blue iceberg.

產生藍色的冰山

An iceberg that has not experienced

還沒有經過

as much compression

這麼多壓縮的冰山

and has a large amount of air and surface edges

裡面還有很多的空氣存在，而其表面

reflects light as white.

反射光為白色

Although they form in far northern or southern areas,

雖然它們是在很遠的 北方及南方形成

icebergs can float thousands of miles.

冰山可以漂浮數千哩

An iceberg from the Arctic floated

一座從北極來的冰山可以漂浮

as far south as Bermuda.

向南遠至百慕達

Antarctic icebergs are mostly trapped

南極冰山則多半被困在

in the Circumpolar Current,

南極洲環流中

never giving them a chance to float north.

沒有機會向北漂流

However, they have been known to interrupt

然而，人們早已知道它們會干擾

shipping lanes between Australia,

在澳洲

South America,

南美

and South Africa.

及南非間的航道

For all their travelling,

因為冰山漫遊移動

many people think

許多人認為

that these slabs of ice are barren of life,

這些冰塊為荒蕪之地

but these seemingly sterile ice slabs

但這些看似不毛的冰塊

also harbor their own complex ecosystems

卻也孕育了屬於自己的複雜生態系統

and they shape the ecosystems

而且它們還會塑造改變

that they pass through.

它們經過之地的生態系統

They become mobile, floating ecosystems.

它們變成移動、漂浮的生態系統

Even in the coldest seas,

即使在最冷的海洋裡

icebergs are always melting,

冰山總是在融化

at least a little bit.

至少會融化一點點

This melting has a major impact

這種融化的過程會對

on the ocean around an iceberg.

環繞冰山的海洋產生重大的影響

The fresh water from the berg

從「山上」流下的淡水

creates a pool of fresh water

會聚集在一起

that can extend a nautical mile away from the iceberg.

可以自冰山向外擴展一海哩遠

This water is colder than the surrounding sea water,

這灘水比四周的海水還冷

and the temperature variation creates thermal currents

而這種溫度的變化會在

in the vicinity of the iceberg.

冰山的附近產生熱對流

Life thrives on and around an iceberg.

生命就在冰山及其四周繁榮生長

Young icefish hide in small ice holes to avoid predators,

幼小的冰魚藏在小冰洞裡 以躲避掠食動物

while a variety of invertebrates,

而各種無脊椎動物

like jellyfish and siphonophores,

如水母及管水母

congregate in the area.

則聚集在該區域

Many of them come to feed on krill,

多數來捕食磷蝦

tiny shrimp-like creatures.

一種很像蝦的生物

Snow petrels nest on the icebergs

雪燕在冰山上築巢

and feed on the sea life nearby.

並且靠附近的海洋生物為食

Whales and seals and penguins seem to like them too.

鯨魚及海豹及企鵝 似乎也很喜歡它們

And even now that you know all this,

而即使現在你已經知道這一切

we're still at the tip of the iceberg.

我們所知的仍只是冰山一角

There are all sorts of things

還有各式各樣關於冰山的事

we don't know about icebergs.

是我們還不知道的

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

或許你能看得更深一點？