How to study and learn about earthquakes?

Winthrop witnessed an interesting spectacle. Slab pavement on which he walked, for a moment, sat up and dropped back, but not all at once and in sequence. It was like a wave. From this observation, the scientist concluded that an earthquake occurs in waves. With this guess, and started seismology - the study of earthquakes. After some time, a British priest John Michel published his observations and conclusions about the nature of the earthquake. Michel figured out about the speed of propagation of tremors. Its rate is about 1800 kilometers per hour. Scientists have found that seismic waves are not parallel to one another and diverge rings, such as from a thrown pebble in still water. So there was the concept - the earthquake. It is located on the Earth's surface just above the hearth, or hypocenter - the point at a depth below the earth's crust where the earthquake occurs. In the 19 century earthquake research occupies a prominent Irish engineer Robert Mallet. Using a large powder charges, he created the underground explosions - an earthquake. A scientist has calculated that in a different environment, seismic waves travel at different speeds. In sandy soil the slowest - 900 kilometers per hour, the fastest in the granite strata - 1800 miles per hour. In the same century invented the first device that records an earthquake. It was called seismograph. This device consisted of a pendulum, steel weights, which is on a spring or a thin wire suspended from a rack, fastened in the ground. To the pendulum was attached a pen that drew a continuous line on a paper strip. With rapid fluctuations of soil shaken paper with her. Metal pendulum with a stylus on inertia remain motionless. On paper, there is a wavy line, reflecting the fluctuations of the soil. Seismology, the science continued to evolve. English scholar John Milne proposed the creation of the entire planet network of seismic stations. In 1902 his dream came true. All seismic stations were created to send their data to the Milne Institute. Over the next fifty years, seismology has evolved into a serious science, for which all that concerns about earthquakes had no mysteries. Seismologists have learned quite accurately determine how, where, when and what force is tremors. Past experience has allowed seismologists to think seriously on the problem of earthquake prediction. The first earthquake that was predicted has happened on Feb. 4, 1975 in China, Liaoning Province. Warned in advance residents fled their homes in advance and spread to surrounding fields and meadows. The earthquake began at eight o'clock in the evening. Severely damaged houses, bridges and roads. But because the fire was extinguished around beforehand, did not raise no fire. Killed only 300 people. If the population was not warned, that in such a populous province of Liaoning as it would be at least 100,000 victims. But to predict every earthquake is not yet possible and therefore the technology and seismologists engaged in the problem of creating earthquake-resistant buildings.