Near a fault, both the shifting of large blocks of Earth's crust, called fault slippage, and the shaking of the ground due to seismic waves cause destruction. Away from the fault, shaking produces most of the damage. Undersea earthquakes may cause huge tsunamis that swamp coastal areas. Other hazards during earthquakes include rockfalls, ground settling, and falling trees or tree branches. Fault slippage
The rock on either side of a fault may shift only slightly during an earthquake or may move several feet or meters. In some cases, only the rock deep in the ground shifts, and no movement occurs at the earth's surface. In an extremely large earthquake, the ground may suddenly heave 20 feet (6 meters) or more. Any structure that spans a fault may be wrenched apart. The shifting blocks of earth may also loosen the soil and rocks along a slope and trigger a landslide. In addition, fault slippage may break down the banks of rivers, lakes, and other bodies of water, causing flooding.
Ground shaking
Ground shaking causes structures to sway from side to side, bounce up and down, and move in other violent ways. Buildings may slide off their foundations, collapse, or be shaken apart.
Liquefaction
In areas with soft, wet soils, a process called liquefaction may intensify earthquake damage. Liquefaction occurs when strong ground shaking causes wet soils to behave temporarily like liquids rather than solids. Anything on top of liquefied soil may sink into the soft ground. The liquefied soil may also flow toward lower ground, burying anything in its path.
Tsunamis
An earthquake on the ocean floor can give a tremendous push to surrounding seawater and create one or more large, destructive waves called tsunamis, also known as seismic sea waves. Some people call tsunamis tidal waves, but scientists think the term is misleading because the waves are not caused by the tide. Tsunamis may build to heights of more than 100 feet (30 meters) when they reach shallow water near shore. In the open ocean, tsunamis typically move at speeds of 500 to 600 miles (800 to 970 kilometers) per hour. They can travel great distances while diminishing little in size and can flood coastal areas thousands of miles or kilometers from their source.
Structural hazards
Structures collapse during a quake when they are too weak or rigid to resist strong, rocking forces. In addition, tall buildings may vibrate wildly during an earthquake and knock into each other
Seismic waves produced by earthquakes damage buildings and other structures by making them move in various ways. The vibrations can cause houses to slide off their foundations, and can make buildings contract, expand, shake from side to side, and bounce up and down.
Fire
A major cause of death and property damage in earthquakes is fire. Fires may start if a quake ruptures gas or power lines. The 1906 San Francisco earthquake ranks as one of the worst disasters in United States history because of a fire that raged for three days after the quake
Other hazards
Other hazards during an earthquake include spills of toxic chemicals and falling objects, such as tree limbs, bricks, and glass. Sewage lines may break, and sewage may seep into water supplies. Drinking of such impure water may cause cholera, typhoid, dysentery, and other serious diseases.
Loss of power, communication, and transportation after an earthquake may hamper rescue teams and ambulances, increasing deaths and injuries. In addition, businesses and government offices may lose records and supplies, slowing recovery from the disaster.
译文:
地震如何造成破坏？
在靠近地质断层的地方，大面积的地球地壳会移动，我们称之为断层滑移，地震波还会导致地面晃动，这二者共同作用会造成很大的破坏力。在远离地质断层的地方，大部分的毁坏则是由于晃动造成的。海底地震可能会造成巨大的海啸，吞噬沿海区域。在地震中发生的灾难还包括崩塌、地面沉降以及树木或树枝倒塌。
断层滑移
断层两侧中任一一侧的岩石在地震中都可能会轻轻移动一点或者移动几英尺乃至几米。有时，只有地下深层的岩石会移动，地表上的岩石则不发生移动。但是，在很剧烈的地震中，地面可能会突然提升20英尺（即6米）或者更多。任何处在断层带上的建筑都会被撕裂。地表上移动的土木沙石也会导致斜坡上的土质变得松软，松动岩石，导致山体滑坡。此外，断层滑移还可能会导致河岸、湖岸以及其他水体的垮塌，造成洪水。
地面晃动
地面晃动会导致建筑物左右摇摆，上下起伏以及剧烈移动。房屋可能会地基不保、坍塌或者被分裂。
液化
在多软土和湿土的地方，液化进程会加剧地震的破坏力。当强烈的地面晃动导致湿土暂时性地如同液体而非泥土般流动时，液化现象就产生了。在被液化了的土壤上，任何的事物都会陷入松软的地面中。液化了的土壤还会流到地势较低的地面上，并掩埋沿路的所有事物。
海啸
发生在洋底的地震会对其周围的海水产生一个巨大的推动力并且形成一个或多个更大、破坏力更强的波浪，我们称之为海啸，也被称为地震海浪。有些人将海啸称作潮汐波，但是科学家们认为这个术语容易误导他人，因为海啸并不是由于潮汐引起的。当海啸到达靠近岸边的浅水区域时，其高度可能会达到甚至超过100英尺（30米）。通常而言，在开放海域，海啸的移动速度会达到每小时500至600英里（800到970千米)。在海啸传播过程中，它会移动很长一段距离，但是自身的大小却稍有变化。海啸能够淹没离其震源数千英里甚至数千公里的沿海海域。
建筑物的危险
如果建筑物不够牢固、坚硬，无法抵挡强大的晃动力时，建筑物就会倒塌。此外，在地震中，高建筑物还会大幅度晃动，甚至互相撞击。
地震造成的地震波会造成大楼及其他建筑物肆意晃动，进而造成破坏。震动会导致房屋地基不稳，造成建筑物收缩、膨胀、左右摇晃以及上下浮动。
火灾
地震中造成人员死亡及财产损失的一个主要原因就是火灾。如果晃动造成了煤气管道或电路的破裂，就可能发生火灾。1906年圣弗朗西斯科的地震之所以成为美国历史上最严重的灾难就是由于在地震后，火灾肆虐长达三天。
其他灾害
地震还会造成一些其他的灾害，包括有毒化学物的泄露，诸如树枝、砖块和玻璃等的物体坍塌，再如，下水管可能会破裂，污水可能渗入供水系统中。饮用这些不洁净的水会造成霍乱、伤寒、痢疾以及其他严重的疾病。
地震后，电力、通讯以及交通的中断都会阻碍援救人员及医疗队伍的到达，致使伤亡人数才增多。除此之外，还会导致营业场所的存活及政府机关的记录遭受损失，延缓灾后的重建工作。