The Powerful Disaster in Underground: Earthquake
An earthquake is one of the most common naturel and uncontrollable disaster that the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Another definition about earthquake is that “confined to particular active regions of the earth's crust corresponding to the edges of the tectonic plates, and most earthquakes are due to the release of force energy associated with the relative motions of the plates” .There are a lot of causes for why earthquake happened.
Tectonic activity one of the major factor causing to earthquake. Plate tectonics refers to any movement of the earth's crust over the liquid mantle below it. “The surface of the earth is often moving at an extremely slow rate, and the shifting of continental plates has shaped how the continents look over millions years.”  When the shifting plates move against each other, this can lead to earthquakes. The second factor is related also plate tectonic is that plate boundaries. There are four different types of interaction when two plates are next to each other. “Divergent plates are moving apart, so they are more likely to cause volcanoes than earthquakes, since molten material under the plates can move up into the opening crack” . At convergent boundaries, one plate slips under the other, a process called subduction. This can lead to large earthquakes, especially when pressure builds up and a big slip happens all at once. Transform boundaries appear when two plates shift past each other in opposite directions, another potential source of earthquakes.
On the other hand “earthquakes related to volcanic activity may produce hazards which include ground cracks, ground deformation, and damage to manmade structures.”  There are two general categories of...