地震的术语和相关知识

　　　The structure of the Earth as eggs, can be divided into three tiers. Centre-is "egg yolk" - core and intermediate "egg white" - the mantle; outer layer is the "eggshell" - the crust. Earthquake occurred in the crust in general. Earth's rotation and keep the revolution, while the crust is constantly changing internal. The resulting in the role of the crustal deformation of rocks, broken, dislocation and then the earthquake. Underground is where the earthquake epicenter. Source upward from the vertical to the surface where is the epicenter. From the epicenter of the distance to the source told focal depth. Source concentration of less than 70 km of the earthquake was shallow earthquake, in between 70-300 kilometers to the earthquake in the earthquake, more than 300 kilometers of seismic source for deep earthquakes. Focal depth of the earthquake is the most in 1963 in Indonesia Irian Jaya province in northern waters of the 5.8 earthquake, the focal depth of 786 km. For the same size of the earthquake, the focal depth not the same, not the same, the damage caused on the ground level is not the same. On the source, the GREater the damage, but also affected the scope of the smaller, and vice versa.

　　        With a certain distance from the epicenter of the call from the epicenter. Less than 100 kilometers from the epicenter of the earthquake known as the local earthquake, in the 100-1000 km between the recent earthquake known as the earthquake, more than 1,000 kilometers of the earthquake as far tremor, which, the farther away from the epicenter of the impact on local and The smaller the damage.

　　        Caused by the earthquake ground vibration is a complex exercise, it is by the P-wave and S-wave interaction results. In Zhenzhong Qu, longitudinal wave to the ground moving from top to bottom Britain. S-wave shaking the ground level. As P-wave spread faster, also decay faster, slower S-wave transmission, the decay also slower, so far away from the epicenter, are often not aware of beating from top to bottom, but was able to reach the level of shaking.

　　        The size of the earthquake itself, with that magnitude, according to the release of the earthquake wave energy flexibility to determine the size of magnitude, China's general use of the Richter scale. Usually less than the 2.5 earthquake Jiaoxiao earthquake ,2.5-4 .7 earthquake is felt tremors, more than 4.7 earthquake known as the devastating earthquake. Each difference between a magnitude of the earthquake energy released by a difference of about 30 times. For example, a seven earthquake equivalent to 30 6 earthquake, or the equivalent of 900 5 earthquakes, magnitude 0.1 difference, the energy released an average difference of 1.4 times.

　　        When a certain place in a large earthquake, in a period of time, often in a series of earthquakes, one of the largest earthquake known as a main shock, the main shock before the earthquake is pre-earthquake, occurred after the main shock is earthquake aftershock .

　　        Earthquake has a spatial and temporal distribution of. From the time, the seismic active period and a period of quiet alternating cyclical phenomenon. From space, the earthquake was the distribution of a certain band, said the earthquake zone, mainly concentrated in the Central Pacific and the Mediterranean - the two major Himalayan seismic belt. Pacific seismic zone almost the entire world focus on more than 80 percent of shallow earthquakes (0 km to 70 km), all of the source (70 km to 300 km) and deep earthquakes, the energy released by an earthquake about 80 percent of all energy.

　　        Earthquake shook the ground at a certain point is the deGREe of strength of seismic intensity. China's seismic intensity will be divided into 12 degrees.

　　        Magnitude and intensity, although they can reflect the strength of the earthquake, but also have the same meaning. Earthquake with a magnitude only one, but because of the intensity varies in different places, not the same intensity value. For example, February 10, 1990, Changshu - Taicang 5.1 earthquake occurred, some people say that is four in Suzhou, Wuxi is three, this is wrong. No matter where, can only say that the Changshu - Taicang 5.1 earthquake occurred, but the earthquake in the sand Town, Taicang seismic intensity of 6 deGREes, in Suzhou seismic intensity of 4 degrees, in Wuxi seismic intensity of 3 degrees.

　　        Seismic intensity is a term frequently used. Intensity of a qualitative and quantitative criteria. China's seismic intensity on the table, the people the impression that the general level of damage to housing and other phenomena described, can be used as the basis for determining intensity.