国家地理-2008-05-15 Earthquake 地震的危害

April 18, 1906, California's San Andreas Fault snaps, shaking San Francisco for nearly 60 terrifying seconds .When the trembling stops, the disaster is only beginning.
 
Gas lines rupture¹, setting off massive fires, some 700 people die. Most of the city is reduced to ruins. This trembling of the ground caused when masses of rocks suddenly shift below the Earth’s surface is called an earthquake.
 
Hundreds of little earthquakes shake the planet every day, but most pass unnoticed. They usually occur along the boundaries of the thin plates that cover the Earth like an egg shell. Driven by the heat deep within the Earth’s core, the plates grind against each other along lines called faults. When a plate’s motion is blocked, stress builds up. Finally the fault gives way. The released energy raises through the Earth in the form of seismic² waves .Scientists record these waves on a device called a seismograph.These zigzag³ lines show the strength of various seismic waves. Using the line, scientists grade the earthquakes on the Richter scale. For a quake to measure one number higher on the Richter scale, it must release about 30 times as much energy as the number below it.
 
Every year about 100,000 earthquakes rumblethrough the ground hard enough for people to feel them. Of these, only about 1,000 are strong enough to damage property. But a powerful earthquake can be devastating⁴. On average, about 10,000 people die each year as a result of earthquakes .The greatest recorded earthquake ever to hit North America measured a massive 9.2 .The tremor⁵ struck Alaska on March 28, 1964. A camera onboard a ship docked in Valdez recorded the draining of the entire harbor as a chasm⁶ opened up on the seafloor.
 
There is no stopping the surface of the Earth from changing and moving, so engineers are focusing on ways to create better buildings, highways and bridges, structures that will remain safe and stay in one piece the next time the Earth begins to shake.

1. fault : n.
a large crack in the rocks that form the Earth's surface
2. seismograph: n.
an instrument that measures and records the movement of the earth during
3. chasm: n.
a very deep space between two areas of rock or ice, especially one that is dangerous

 
 
 

1 rupture   

n.破裂；(关系的)决裂；v.(使)破裂

参考例句：

• I can rupture a rule for a friend.我可以为朋友破一次例。
• The rupture of a blood vessel usually cause the mark of a bruise.血管的突然破裂往往会造成外伤的痕迹。

2 seismic   

a.地震的，地震强度的

参考例句：

• Earthquakes produce two types of seismic waves.地震产生两种地震波。
• The latest seismic activity was also felt in northern Kenya.肯尼亚北部也感觉到了最近的地震活动。

3 zigzag   

n.曲折，之字形；adj.曲折的，锯齿形的；adv.曲折地，成锯齿形地；vt.使曲折；vi.曲折前行

参考例句：

• The lightning made a zigzag in the sky.闪电在天空划出一道Z字形。
• The path runs zigzag up the hill.小径向山顶蜿蜒盘旋。

4 devastating   

adj.毁灭性的，令人震惊的，强有力的

参考例句：

• It is the most devastating storm in 20 years.这是20年来破坏性最大的风暴。
• Affairs do have a devastating effect on marriages.婚外情确实会对婚姻造成毁灭性的影响。

5 tremor   

n.震动，颤动，战栗，兴奋，地震

参考例句：

• There was a slight tremor in his voice.他的声音有点颤抖。
• A slight earth tremor was felt in California.加利福尼亚发生了轻微的地震。

6 chasm   

n.深坑，断层，裂口，大分岐，利害冲突

参考例句：

• There's a chasm between rich and poor in that society.那社会中存在着贫富差距。
• A huge chasm gaped before them.他们面前有个巨大的裂痕。