This theory states that during an earthquake, the rocks suddenly break from withholding strain over a period of time, and create a fracture along the fault. When the fault begins to slip, movement in the crustal rock causes vibrations. The slip changes the local strain out into the surrounding rock. This change then leads to aftershocks or smaller earthquakes that occur after the initial earthquake, which are produced by additional slips of the main fault or neighboring faults in the strained region. The slip begins at the focus, traveling along the plane of the fault, and radiating waves out along the rupture surface. The rock shifts in opposite directions on either side of the fault. The rupture then begins to travel in irregular steps along the fault; giving rise to the vibrations that propagate as seismic waves. After the first earthquake is over, strain begins to build again until it is greater than the forces holding the rocks together and the fault snaps causing yet another earthquake ( "Earthquakes-).
Using this simple theory ¸ along with other modern seismological technology some scientists actually believe that they can predict earthquakes. However the earthquakes that took place in both 1989 and 1993 came as a complete surprise in spite of the technology, which proves that there may never be an absolutely reliable predictor of earthquakes (Beiser & Krauskopf 481). .
Although they can not be predicted and sometimes only last a matter of mere seconds, the damages associated with an earthquake can destroy entire regions so it is important to know as much about earthquakes as possible. Therefore an important model to familiarize one's self with might be the Richter scale. Dr. Charles F. Richter is responsible for recognizing that the seismic waves radiated by all earthquakes can provide good estimates of their magnitudes. Magnitude is the energy released by each earthquake.
