Реферат: Earthquakes Essay Research Paper Every year there
Earthquakes Essay, Research Paper
Every year there are about a million earthquakes. Fortunately, not all of them are destructive. The intensity of an earthquake is measured on the Richter Scale, which goes from zero upward. Major damage generally occurs from earthquakes ranging from 6.0 upwards. The damaging earthquakes also occur either in the narrow belt, which surrounds the Pacific Ocean or in a line, which extends from Burma to the Alps in Europe. Earthquakes are one of natural wonders of the world that cause the most deaths and destruction every year.
The actual cause of an earthquake is the rupturing or breaking of rocks at or below the earth s surface. The breaking of the rocks is produced by pressure. The pressure is due to the motion of immense rigid plates at the surface of the earth in response to the flow of rock within the earth. As the motion continues, the strain builds up to the point where the rock cannot withstand any more bending. With a lurch, the rock breaks and the two sides move. An earthquake is the shaking that radiates out from the breaking rock.
The effects of earthquakes are responsible for a large number of deaths and vast amounts of destruction in various parts of the world. The most common effect associated with earthquakes is the ground shaking. The severity of the ground shaking depends on the magnitude of the earthquake and local geological conditions. Another effect earthquakes have is soil liquefaction. Soil liquefaction occurs where there is a high water content. The soil loses its strength and behaves like a fluid, when violent shaking occurs. Landslides, rock and snow avalanches are also effects of earthquakes that usually occur in mountainous areas. They are due to strong shaking that make the slopes fall, which turn into landslides or avalanches. Earthquakes that occur under the ocean cause tsunamis. Tsunamis are huge waves that are barely noticeable until they approach coastal areas, where the waves can reach over twenty meters in height and flood the area.
In order to minimize the damage and to alleviate some of the suffering resulting from earthquakes, scientists are working on ways to facilitate accurate prediction. Seismographs and tilt meters are two of the instruments that help to predict earthquakes. By the means of calculations, seismologists can accurately indicate the exact time, location, and size of an earthquake. Tilt meters are used to record any changes in the tilt of the land, which help estimate the occurrence of any earthquake activity in the future.
Earthquakes are one of the most unpredictable natural causes for death and destruction in the world. Even though scientists know the cause of earthquakes, which is the breaking of rocks at or below the earth s surface, it is hard for them to predict everyone. Scientists are currently working on more ways to predict earthquakes due to the major destruction and large amount of deaths they leave behind in such a short time period. By the use of seismographs and tilt meters, scientists are now able to indicate the exact time, location, and size of an earthquake. This has dramatically reduced the number of deaths and the amount of destruction caused by earthquakes over the pasted few years.