-
(单词翻译:双击或拖选)
You've heard about them, and maybe seen them in movies as they smash apart ocean liners, or wash whole cities into the sea. What causes tidal waves, and how are they different from the ordinary waves that wash against our coastlines? Tidal waves actually have nothing to do with tides, and nothing to do with ordinary ocean waves. They're more properly called "tsunamis2," which is Japanese for "harbor waves." It's a good name because, although tidal waves lie relatively3 flat on the open ocean, they can pile up tremendously high when they hit the shallower water of a continental4 shelf or harbor. Ordinary ocean waves are caused by the action of wind, like ripples5 on a wind-blown pond. Even the impressive surf of the Pacific got its start as wind blowing across the open water. The height of such waves depends on how fast the wind is blowing, and how much open water the wind travels across. Tsunamis, however, have nothing to do with wind. They're caused by the sudden movement of the Earth's crust during an underwater earthquake or a volcanic6 eruption7. Imagine a child's plastic wading8 pool filled with water in the back yard. Ordinary waves are like the little surface ripples from the afternoon breeze. A tsunami1 is what you'd get if you kicked the side of the pool. Tsunamis can travel thousands of miles, and still send water crashing a hundred feet high into a harbor or coastal9 town. A 1960 earthquake in Chile sent tsunamis across the Pacific at three hundred miles per hour, destroying harbors in Hawaii and Japan. On our next program, we'll learn what it's like to meet a tsunami on the open ocean.
1 tsunami | |
n.海啸 | |
参考例句: |
|
|
2 tsunamis | |
n.海啸( tsunami的名词复数 ) | |
参考例句: |
|
|
3 relatively | |
adv.比较...地,相对地 | |
参考例句: |
|
|
4 continental | |
adj.大陆的,大陆性的,欧洲大陆的 | |
参考例句: |
|
|
5 ripples | |
逐渐扩散的感觉( ripple的名词复数 ) | |
参考例句: |
|
|
6 volcanic | |
adj.火山的;象火山的;由火山引起的 | |
参考例句: |
|
|
7 eruption | |
n.火山爆发;(战争等)爆发;(疾病等)发作 | |
参考例句: |
|
|
8 wading | |
(从水、泥等)蹚,走过,跋( wade的现在分词 ) | |
参考例句: |
|
|
9 coastal | |
adj.海岸的,沿海的,沿岸的 | |
参考例句: |
|
|