时差N小时:火山与水 Volcanos and Water

Firefighters use water to battle a towering inferno.

消防员用水来扑灭熊熊燃烧的大火，

You might wonder if water could also stifle anerupting volcano.

你或许想知道水是否也可以用来扑灭喷发的火山。

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

事实上，每次海底火山喷发就是对此进行的一个实验。

What happens when a volcano erupts underwater?

当海底火山喷发时，都发生了什么呢?

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

我们今天就跟随科学一刻栏目一起探个究竟吧。

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

世界上大多数的火山活动都发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.

在海底大约有一百万座火山。

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，就是由华氏几千度的炽热的岩浆从海底向上冲出而成。

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

海水并不能像消防员灭火一样扑灭火山，

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

但是当岩浆冲出地面时，它确实能起到不小的作用。

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

扑灭海底火山和地面的火山最大的不同在于水的压力，与水的湿度并没有关系。

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

在这样的深度，水压可以是地面上空气压力的250多倍。

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

压力可以阻止岩浆中形成气泡，这也就消除了地面火山爆炸性喷发的可能性。

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，岩浆就像牙膏挤出管子那样挤出地面，形成一道道玻璃般的岩层，看起来就想是一条长长的堆叠的枕头。

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

压力是如此巨大，以至于这些岩石接触到海水时连水蒸汽都还无法形成。

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

因此，你或许就曾经驾船行驶在一个巨大的喷发的火山上而丝毫没有察觉。

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

所以，用水不可能扑灭火山。

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

但是在我们下一期的节目中我们将会告诉您一个镇子曾经试图这样做，而且从某种程度上来说，他们成功了!