【英语时差8,16】如何测量地震波（下）

The earth is its own ultrasound machine. All scientists have to do is record when and where the waves occur. Scientists measuring layers of rock in an area of the Pacific floor called the Nankai Trough discovered why earthquakes trigger¹ tsunamis² from that area. A major fault runs from six miles deep right up to the sea floor. When an earthquake happens there, the fault lets the sea floor move up and down, creating large waves. Other scientists in the San Francisco Bay area have mapped the area to determine where faults are located and where earthquakes will occur.

1 trigger   

n.触发器，板机，制滑机；v.触发（事件）

参考例句：

• His index finger tightened on the trigger but then relaxed again.他的食指扣住扳机，然后又松开了。
• He pulled the trigger but the gun didn't go off.他打了一枪，没有发火。

2 tsunamis   

n.海啸( tsunami的名词复数 )

参考例句：

• Our oceans are alive with earthquakes, volcanoes, and more recently, tsunamis. 海中充满着地震、火山，包括最近发生的海啸。 来自常春藤生活英语杂志-2006年2月号
• Please tell me something more about tsunamis! 请您给我讲讲海啸吧！ 来自辞典例句