Disaster

An earthquake is a vibration or shock that occurs on the surface of the earth. Earthquakes are usually caused by movement of the earth's crust (tectonic plates). The word earthquake is also used to indicate the origin of the earthquake occurrence. Our Earth is solid though, always moving, and earthquakes occur when the pressure is happening because the movement was already too large to hold. 1. Volcanic earthquakes (Gunung Api) This earthquake occurred as a result of magmatic activity, which usually occurs before the volcano erupted. If its activity the higher it will cause an explosion that also will lead to the occurrence of earthquakes. The earthquake was only felt in the vicinity of the volcano. 2. Tectonic earthquake; This earthquake caused by tectonic activity, namely a shift in plate tectonic plates suddenly having the power of the very small to very large. This earthquake generated a lot of damage or natural disasters on earth, a strong earthquake vibrations can spread throughout the earth. Tectonic earthquakes are caused by perlepasan [power] is happening because of a shift in plate tectonic plates pulled like a rubber band and released abruptly. Power generated by the pressure between the rock known as tectonic disability. The theory of tectonic plates (tectonic plates) explains that the earth consists of several layers of rock, most areas of the crust it will drift and float in layers like the snow. Stir gently so that the layer-break berpecah and collide with each other. This is what causes the occurrence of tectonic earthquake. Map of distribution follow specific patterns and rules and narrowed, the meeting followed the patterns of tectonic plates that make up the crust of the earth. In earth science (geology), a theoretical framework of tectonic plates is postulated to explain the phenomenon of tectonic earthquake that hit almost the entire region, adjacent to the boundaries of tectonic plates meeting. Examples of volcanic earthquakes is as happened in Yogyakarta, Indonesia on Saturday, May 27, 2006 early morning, at 5:54 pm. Earthquakes usually happen at plate boundaries such slabs. The most severe earthquakes usually occur in the compressional and translational plate boundary. The earthquake focus in the most likely to occur because the material is sandwiched into the layers of the lithosphere undergoes phase transition at a depth of more than 600 km. Several other earthquakes can also occur due to the movement of magma inside the volcano. Such an earthquake could be symptoms of impending volcanic eruptions. Several earthquakes (rarely but) also occur because of accumulated huge mass of water behind the dam, such as the Caribbean Dam in Zambia, Africa. The rest of them (also rare) can also occur due to injection or akstraksi fluid from / into the earth (eg in some geothermal power plants and in the Rocky Mountain Arsenal. Finally, earthquakes can also occur from detonation of explosives. This can make scientists to monitor nuclear weapons tests conducted secret government. Earthquakes are caused by humans such as this is also called induced seismicity.