earthquake Essays -- essays research papers

Earthquakes lead plagued our lives for as long as people have inhabited the earth. These grievous acts of the earth have been the cause of many deaths in the past century. So what can be done closely these violent eruptions that take fleck nearly with out warning? Predicting an quake until forthwith has almost been technologically impossible. With improvements in technology, lives have been saved and many more pass on. All that stiff is to research what takes place in front, during, and after an earthquake. This has been done for years to the point now that a successful earthquake prediction was made and was accurate. This paper will discuss a little about earthquakes in general and thusly about how predictions be made. Earthquake, vibrations produced in the earths crust when rocks in which elastic variant has been building up suddenly rupture, and then rebound.(Associated Press 1993) The vibrations can ikon from barely noticeable to catastrophically destructive. Six ki nds of shock waves are generated in the process. Two are classified as body waves-that is, they travel through the earths interior-and the other four are surface waves. The waves are further separate by the kinds of motions they impart to rock particles. Primary or compressional waves (P waves) send particles hesitate back and forth in the same perplexity as the waves are traveling, whereas secondary or transverse shear waves (S waves) impart vibrations perpendicular to their direction of travel. P waves always travel at higher velocities than S waves, so whenever an earthquake occurs, P waves are the first to arrive and to be save at geophysical research stations worldwide.(Associated Press 1993) Earthquake waves were discover in this and other ways for centuries, but more scientific theories as to the causes of quakes were not proposed until modern times. One such concept was advanced in 1859 by the Irish engineer Robert Mallet. Perhaps drawing on his cognition of the streng th and behavior of construction materials subjected to strain, Mallet proposed that earthquakes occurred either by sudden flexure and constraint of the elastic materials forming a portion of the earths crust or by their giving way and becoming fractured.(Butler 1995) Later, in the 1870s, the English geologist bath Milne devised a forerunner of todays earthquake-recording device, or seismograph. A simple pen... ... warned that a major quake would occur along the New Madrid fault in the beginning the end of the year. Like most predictions of this type, it proved to be wrong. Groundwater has also compete an important part in earthquake predictions. A peak in radon in the groundwater at Kobe, Japan 9 days in advance the 7.2 earthquake cause quite a stir. Radon levels peaked 9 days before the quake, then fell below the normal levels 5 days before it hit.(Monastersky July, 95) In North America, the series of earthquakes that struck southeastern Missouri in 1811-12 were probably the most powerful experienced in the United States in historical time. The most famous U.S. earthquake, however, was the one that shake the San Francisco area in 1906, causing extensive damage and taking about 700 lives.(Nagorka 1989) The whole idea behind earthquake predicting is to save lives. With the improvement in technology, lives have been saved. New ideas and equipment is starting to prove to be very implemental in predicting were and when an earthquake will strike. The time and research put into earthquake predicting has already started to pay off. It is only a matter of time before earthquakes will no longer be a threat to us.