听力文摘：测量火山温度

Most of the time, volcanoes look like other mountains:

大多数时候，火山看起来和其他的山体没有两样：

solid,serene, capped with snow–a nice place to go camping.

固体，平静，被积雪覆盖-露营的不错选择。

Unless, of course, it happens to explode and pour molten lava¹ all over your campsite!

除非，当然，它突然喷发，熔浆覆盖你的营地。

Wouldn't itbe nice if we could predict when a volcano was about to erupt?

如果我们能够预测火山什么时候会喷发，是不是更好呢？

Scientists have recently taken a big step closer toward doing just this.

科学家们最近在此领域的研究取得了进展。

Let's look inside a volcano.

让我们一起来看看火山的内部结构吧！

At the center is a reservoir of molten rock, known as magma.

中心是一个熔岩的“液态区”，叫岩浆。

This magma is very hot, and under a lot of pressure.

岩浆温度很高，并且处于一定的压力之下。

When rainwater seeps² into cracks in themountain, the magma turns it into steam and forces it out again.

当雨水渗入山缝后，岩浆将其蒸发为水蒸汽，又让它排放出来。

The magma also vents⁴ awayhot gasses through these same cracks.

岩浆也同样通过这些山缝散发一些热气。

This is a volcano's normal state.

这是一座火山的正常状态。

When gasses and steam vent³ from a volcano's cracks, it'sprobably not about to erupt.

当气体和蒸汽可以从火山的裂缝排放时，它可能并不会喷发。

Sometimes, however, the top layer of magma can cool, and form ahard crust over the rest of the molten rock.

然而，有时顶层的岩浆会冷却，并在外部形成一个坚硬的壳。

When this happens, rainwater is able to collect in thecracks without evaporating, and this water captures a lot of gasses that would ordinarily vent fromthe magma.

这时，雨水聚集在岩缝中，不能蒸发。这些雨水阻止了岩浆热气的排放。

Scientific instruments inside the volcano's cracks record a sudden drop in temperature, and much less volcanic⁵ gas.

在山缝中的科学仪器记录到了温度的陡然下降，和火山气体的减少。

This is a warning sign for an imminent⁶ eruption⁷.

这是即将喷发的一个预兆。冷却的岩浆壳让内部的液体压力增大。

That cool magmaseal allows pressure to build upinside the liquid magma, much like your thumb over the top of a shaken soda⁸ bottle will seal inthe pressure.

就像把你的拇指放在被摇过的苏打水瓶口上，使其密封，增加内部压力。

When that magmaseal gives way it's like taking your thumb off the top of the bottle, and you don't want to be camping on the volcano when that happens!

岩浆上部的密封壳被冲开时，就像你的拇指从苏打水瓶上拿开的时候一样，在这种情况下，你就不会想要在火山上露营了。

1 lava   

n.熔岩，火山岩

参考例句：

• The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
• His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。

2 seeps   

n.（液体）渗( seep的名词复数 )；渗透；渗出；漏出v.（液体）渗( seep的第三人称单数 )；渗透；渗出；漏出

参考例句：

• Water seeps through sand. 水渗入沙中。 来自《现代汉英综合大词典》
• Water seeps out of the wall. 水从墙里沁出。 来自《现代汉英综合大词典》

3 vent   

n.通风口，排放口；开衩；vt.表达，发泄

参考例句：

• He gave vent to his anger by swearing loudly.他高声咒骂以发泄他的愤怒。
• When the vent became plugged,the engine would stop.当通风口被堵塞时，发动机就会停转。

4 vents   

（气体、液体等进出的）孔、口( vent的名词复数 )； （鸟、鱼、爬行动物或小哺乳动物的）肛门； 大衣等的)衩口； 开衩

参考例句：

• He always vents his anger on the dog. 他总是拿狗出气。
• The Dandelion Patch is the least developed of the four active vents. “蒲公英区”在这四个活裂口中是发育最差的一个。

5 volcanic   

adj.火山的；象火山的；由火山引起的

参考例句：

• There have been several volcanic eruptions this year.今年火山爆发了好几次。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

6 imminent   

adj.即将发生的，临近的，逼近的

参考例句：

• The black clounds show that a storm is imminent.乌云预示暴风雨即将来临。
• The country is in imminent danger.国难当头。

7 eruption   

n.火山爆发；（战争等）爆发；（疾病等）发作

参考例句：

• The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
• The eruption of a volcano is spontaneous.火山的爆发是自发的。

8 soda   

n.苏打水；汽水

参考例句：

• She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
• I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。