Earthquake is also called the ground shaking, to vibration, is the rapid release of energy in the process of earth's crust caused vibration, generates seismic waves during a natural phenomenon.Earth jostling each other between plate and plate, plate edge and plate internal produce dislocation and fracture, is the main cause of ground vibration (earthquake) [1].
Started happening earthquake site is called the source, the source is directly above the ground is called the epicenter.The devastating earthquake ground vibration called the magistoseismic area, the most strong place magistoseismic area that is often the epicenter area [2].Earthquake often cause serious casualties, can cause fires, floods, poisonous gas leak, the proliferation of bacteria and radioactive substances, can also cause tsunamis, landslide, collapse, ground cracks and other secondary disasters.
According to statistics, about 500 a year on earth more than ten thousand earthquakes, the earthquake happened thousands of times a day.The vast majority are too small or too far that people won't feel;Really can do serious harm to human about a decade or two earthquakes;Can cause especially serious disaster earthquake about once or twice.People do not feel the earthquake, must be recorded by seismograph;Different types of seismometers can record different intensity, different distance of the earthquake.Running thousands of various instruments in the world day and night monitoring with the trend of the earthquake.[3]
On March 28, 2014, 09, 9 p.m. eastern city of Los Angeles, a magnitude 5.1
earthquake in la habra again confirm earthquake is predictable.The United States geological survey earthquake early-warning system prototype function, make the local earthquake scholars 4 seconds in advance to predict the arrival.
