時差N小時:火山與水 Volcanos and Water

Firefighters use water to battle a towering inferno.

消防員用水來撲滅熊熊燃燒的大火，

You might wonder if water could also stifle anerupting volcano.

你或許想知道水是否也可以用來撲滅噴發(fā)的火山。

Actually, this experiment happens every timeavolcano erupts at the bottom of the ocean.

事實上，每次海底火山噴發(fā)就是對此進行的一個實驗。

What happens when a volcano erupts underwater?

當海底火山噴發(fā)時，都發(fā)生了什么呢?

We'll find it out on today's moment of science.

我們今天就跟隨科學一刻欄目一起探個究竟吧。

Most of the world's volcanic action happens an average of eight thousand five hundredfeetunderwater.

世界上大多數(shù)的火山活動都發(fā)生在海平面以下平均8500英尺的地方。

Deep beneath the waves there are an estimated one million volcanos.

在海底大約有一百萬座火山。

As with land volcanos, molten lava pushes up from beneath the sea floor at thousands ofdegrees Fahrenheit.

至于地面上的火山，就是由華氏幾千度的熾熱的巖漿從海底向上沖出而成。

Ocean water can't “put out” the volcano the way firefighters put out a fire,

海水并不能像消防員滅火一樣撲滅火山，

but it does have aprofound effect on what happens to the lava once it's out of the ground.

但是當巖漿沖出地面時，它確實能起到不小的作用。

The biggest difference between undersea and land volcanos has nothing to do with water'swetness, but with its pressure.

撲滅海底火山和地面的火山最大的不同在于水的壓力，與水的濕度并沒有關系。

At these depths, the water pressure can be two hundred and fifty times more powerful than airpressure at the Earth's surface.

在這樣的深度，水壓可以是地面上空氣壓力的250多倍。

This prevents bubbles from forming in the lava, eliminating the likelihood of an explosiveeruption like some land eruptions are.

壓力可以阻止巖漿中形成氣泡，這也就消除了地面火山爆炸性噴發(fā)的可能性。

Instead, lava squeezes out of the ground like tooth paste out of a tube, forming glassy rockformations that look like long, stacked pillows.

相反，巖漿就像牙膏擠出管子那樣擠出地面，形成一道道玻璃般的巖層，看起來就想是一條長長的堆疊的枕頭。

The pressure is so high that steam never even forms where lava touches water.

壓力是如此巨大，以至于這些巖石接觸到海水時連水蒸汽都還無法形成。

You could be in a boat over a giant, erupting volcano, and never even know it was there.

因此，你或許就曾經駕船行駛在一個巨大的噴發(fā)的火山上而絲毫沒有察覺。

So,you can't put out a volcano with water.

所以，用水不可能撲滅火山。

But on our next program, we'll find out whathappened to a town that tried to do this anyway-and in a way succeeded!

但是在我們下一期的節(jié)目中我們將會告訴您一個鎮(zhèn)子曾經試圖這樣做，而且從某種程度上來說，他們成功了!