There are no natural disasters that cause nearly as much damage in a short period of time as earthquakes. Urban areas in particular are susceptible to grave human loss in the event of major earthquakes.Earth's crust is divided into several tectonic plates with each plate moving gradually over the years. When two plates collide, huge friction at the fault line cause both plates to distort. When the distortion reaches its limit, plates move violently resulting in earthquakes.Magnitude of earthquake is determined by the amount of displacement at the fault line, which is unpredictable. Earthquake resistant buildings are necessary using shock absorbing foundations and counter-weight system to offset seismic vibrations.Even if a building's outer structure survives an earthquake, internal damages may be quite severe. Safety devices are now being developed to better absorb vibrations and fasten fixtures in place. Also, early warning systems are now being installed in buildings throughout the world to provide forewarning of impending earthquakes.
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