翻译学习：什么是地震?

KOBE House Collapse Photograph by Mosanori Kobayashi

Earthquakes, also called temblors, can be so tremendously destructive, it’s hard to imagine they occur by the thousands every day around the world, usually in the form of small tremors.地震的另一个表达是“temblors”，是有可能造成极大破坏力的灾难。但其实你知道吗？世界上各个角落每天都在发生着的小型地震多到难以计数。Some 80 percent of all the planet's earthquakes occur along the rim of the Pacific Ocean, called the "Ring of Fire" because of the preponderance of volcanic activity there as well. Most earthquakes occur at fault zones, where tectonic plates—giant rock slabs that make up the Earth's upper layer—collide or slide against each other. These impacts are usually gradual and unnoticeable on the surface; however, immense stress can build up between plates. When this stress is released quickly, it sends massive vibrations, called seismic waves, often hundreds of miles through the rock and up to the surface. Other quakes can occur far from faults zones when plates are stretched or squeezed.世界上80%的地震和火山发生在环太平洋火山地震带上。大多数地震发生在断层带——也就是大陆板块的交界处，当两块板块移动相撞的时候就会引发地震或火山爆发这类地质灾害。尽管我们并无法感觉到板块之间碰撞力量的积聚，但是当板块摩擦力量积聚到一定程度的时候就会引起迅速的释放。当地震发生的时候，地震波会通过岩石从数百里外传达到地表引起振动。而不发生在断层带上的地震则属于另一类地震，它们是由板块扩张或压缩所引起的。Scientists assign a magnitude rating to earthquakes based on the strength and duration of their seismic waves. A quake measuring 3 to 5 is considered minor or light; 5 to 7 is moderate to strong; 7 to 8 is major; and 8 or more is great.根据地震的强度和地震波的辐射范围，科学家把地震分成不同的级别：3-5级是轻震，5-7级是中级强度，7-8级被定义为大地震，8级