An earthquake is the perceptible shaking of the surface of the Earth, which can be violent enough to destroy major buildings and kill thousands of people. The severity of the shaking can range from barely felt to violent enough to toss people around.
The following are the effects of the earthquake:
- Fires often break out following earthquakes. Fires can easily get out of control since during the earthquake there are many demands made on the emergency response systems that slow down response to fires.
- Tsunamis, underwater earthquakes, volcanos, or landslides can produce a tsunami or tidal wave. This wave can travel very rapidly thousands of miles across the ocean. In deep water, the tsunami may only raise the ocean level by a few centimeters, hardly enough to notice. But as it approaches land, the shallower water causes the wave to build in height to as much as 10-20 meters or more and suddenly flood coastal areas. Tsunamis carry a lot of energy and when they hit the coast strong currents can cause massive erosion of the coastline as well as tearing apart buildings it encounters. Typically, a tsunami will last for a period of hours with successive waves drastically lowering and raising the sea level. Although scientists now understand the causes of tsunamis, there are many local factors including the slope of the seafloor at a given location, the distance, and the direction of travel from the earthquake that will determine the severity of the resulting wave.
- Landslides, buildings can be damaged when the ground gives way beneath them. This can be in the form of a landslide down a hill, or liquefaction of soils. Ground movement can change the whole landscape.
- Building Collapse, people can be trapped in collapsed buildings. This is the type of damage that leads to the worst casualties. The worst thing to do in a quake is to rush out into the street during the quake. The danger from being hit by falling glass and debris is many times greater in front of the building than inside. Buildings that can otherwise withstand the quake can be knocked off their foundations and severely damaged
- Electric lines and gas mains can snap
- Large areas of ground can shift position
- Movement in large bodies of water
- Dam failures
- Surface fault ruptures
- Soil Liquefaction: This occurs when shaking during an earthquake causes saturated granular material to lose its strength and act as a liquid. This allows heavy structures to become very unstable and sink into the ground. Areas susceptible to liquefaction include low-lying areas which are water-saturated, loose sandy soils, and poorly compacted artificial fill. Release of hazardous materials If tanks or other structures containing these materials are damaged the chances of a release are increased.