評(píng)論
打印
Tsunamis are powerful waves caused by underwater earthquakes or eruptions that can crashover ten stories tall into a coastline.
海嘯是由海底的地震或者火山噴發(fā)引起的足以把一個(gè)十層高樓淹沒的強(qiáng)大海浪。
If you were sailing far from shore, how would you feel about a tremendous tsunami heading your way?
如果你正遠(yuǎn)離海岸航行，這時(shí)遭遇了海嘯，是什么樣的感覺呢？
Actually, you wouldn't notice a tsunami at all.
事實(shí)上，你根本不會(huì)注意到海嘯。
In deep water, a tsunami raises the ocean's surfaceonly about one or two feet—much less than ordinary ocean waves.
在深海中，海嘯只會(huì)掀起一或兩英尺的海浪-遠(yuǎn)遠(yuǎn)低于普通的海浪。
What's more, it takes up to an hour for a single tsunami to roll by.
更重要的是，一次海嘯最多一個(gè)小時(shí)就過去了。
How can a wave be so deadly to a coastline, but so tame inthe open ocean?
為什么對(duì)于海岸如此致命的海浪在公海中如此溫馴呢？
The energy of a wave has more to do with how deep the water churns than how tall the waverises.
海浪的力量與水層波動(dòng)的深度而不是海浪的高度有關(guān)。
Ordinary waves can be rather tall, but they don't go very deep.
常波可能很高，但是它們水體波動(dòng)的深度并不深。
What's more there's nevermuch distance between one ordinary wave's crest and the one following it.
更重要的是常波前后的波峰之間并沒有太大的距離。
The distance betweenwaves is called “wavelength,” and it's another secret of a tsunami's strength.
波之間的距離被稱為“波長(zhǎng)”，這是海嘯力量的另一個(gè)秘密。
While ordinary waves only tug at the surface water, tsunamischurn the water all the way to thedeepest ocean floor!
盡管常波只是在水表面生成，但是海嘯可以在最深的海底引起水層波動(dòng)使其產(chǎn)生。
They also have very long wavelengths—a hundred miles or more.
它們同樣有很長(zhǎng)的波長(zhǎng)一百英里或更多。
Although tsunamis raise the surface only a foot or so in deep water, they carry a lot of energy.
雖然海嘯通過深海中的水層波動(dòng)只能提升水平面一英尺左右，但是它們帶來了大量的能量。
When a tsunami approaches a coastline, the water gets shallower.
當(dāng)海嘯接近海岸線時(shí)，水的深度逐漸變淺。
This causes friction at the frontof the wave and slows it down.
導(dǎo)致波前摩擦，使其速度變慢。
The faster moving back of the wave piles into the slower front,squeezing the whole hundred mile tsunami like an accordion.
快速前進(jìn)的波浪與前面速度較慢的波浪重疊，像手風(fēng)琴那樣擠壓這些整個(gè)百里長(zhǎng)的海嘯。
Just as a rug will crumple and rise if it's scrunched by an opening door, the tsunami gets taller.
正如由于門開時(shí)被壓住而弄皺卷起的地毯，海浪就越來越高。
By the time it hits the beach, it canbe a hundred feet high!
當(dāng)它到達(dá)海灘的時(shí)候，它可以達(dá)到一百英尺。
