29.High School English Listening

Tsunamis are powerful waves caused by underwater earthquakes or eruptions that can crashover ten stories tall into a coastline.
If you were sailing far from shore, how would you feel about a tremendous tsunami heading your way?
Actually, you wouldn't notice a tsunami at all.
In deep water, a tsunami raises the ocean's surfaceonly about one or two feet—much less than ordinary ocean waves.
What's more, it takes up to an hour for a single tsunami to roll by.
How can a wave be so deadly to a coastline, but so tame inthe open ocean?
The energy of a wave has more to do with how deep the water churns than how tall the waverises.
Ordinary waves can be rather tall, but they don't go very deep.
What's more there's nevermuch distance between one ordinary wave's crest and the one following it.
The distance betweenwaves is called “wavelength,” and it's another secret of a tsunami's strength.
While ordinary waves only tug at the surface water, tsunamischurn the water all the way to thedeepest ocean floor!
They also have very long wavelengths—a hundred miles or more.
Although tsunamis raise the surface only a foot or so in deep water, they carry a lot of energy.
When a tsunami approaches a coastline, the water gets shallower.
This causes friction at the frontof the wave and slows it down.
The faster moving back of the wave piles into the slower front,squeezing the whole hundred mile tsunami like an accordion.
Just as a rug will crumple and rise if it's scrunched by an opening door, the tsunami gets taller.
By the time it hits the beach, it canbe a hundred feet high!
译文：
海啸是由水下地震或火山爆发引起的强大波浪，可以将十层楼高的东西撞向海岸线。
如果你在远离海岸的地方航行，你会对一个巨大的海啸冲向你的方向有什么感觉？
事实上，你根本就不会注意到海啸。
在深水中，海啸只使海面上升一到两英尺，比普通的海浪小得多。
更重要的是，一个海啸需要一个小时的时间来滚过。
为什么一个波浪对海岸线如此致命，而在开放的海洋中却如此温顺？
波浪的能量与水的深度有关，而不是与波浪的高度有关。
普通的波浪可能相当高，但它们不会很深。
更重要的是，一个普通波浪的波峰和它后面的波浪之间的距离永远不会太大。
波浪之间的距离被称为 "波长"，它是海啸强度的另一个秘密。
普通的波浪只拉扯表面的水，而海啸却把水一直拉到最深的海底！它们的波长也很长。
它们也有非常长的波长--一百英里或更多。
虽然海啸在深水中只提高了一英尺左右的水面，但它们携带了大量的能量。
当海啸接近海岸线时，水变得更浅。
这导致了波浪前端的摩擦，并使其减慢。
移动速度较快的海浪的后部堆积到较慢的前部，像手风琴一样挤压着整个一百英里的海啸。
就像一块地毯被一扇打开的门挤压后会皱缩上升一样，海啸会变得更高。
当它到达海滩时，它可能有100英尺高。
重点词汇：
far from 远没有 ; 根本不;远远不
would you 行吗 ; 你想 ; 你会不会
feel about 摸索；揣摩 ; 用手在……周围摸以寻找某物 ; 对……有某种感觉
one or two 一两个 ; 几个
much less 更不用说 ; 更何况 ; 遑论
an hour 一小时 ; “an/per hour”的变体
do with 忍受，满足于 ; 处置，对待，对付 ; 需要，想要