How Are Earthquakes Caused?

Have you ever wondered that why do earthquakes happen? In recent years the rate with which the occurrence of earthquakes is witnessed is way more than it was before, the major cause of it ranges from many physical activities to atmospheric changes that happen on earth ‘Earthquakes’ are usually caused when rocky underground breaks due to sudden fault. What happens exactly is that when there is this sudden release of energy it causes the seismic waves to make the ground shake. When two blocks of rocks or if not rocks then two plates under the earth are rubbing against each other, they stick with each other a little. They don't just slide smoothly like the rocks catch on each other. The rocks are then after this still push against each other, but not move.
Sometime after the occurrence of this process, the rocks break because of all the high pressure coming in that has that has built up. It is when the rocks break, the earthquake occurs. During the time of earthquake and afterwards, the plates or blocks of rock start their movement, and they afterwards continue to move till they are tucked again. The spotted underground where the rock breaks is known as the focus of the earthquake and the place which is right above the focus (on top of the ground) is regarded as the epicenter of the earthquake.
Earthquake-like seismic waves can be a result of many other things like it can be caused by explosions underground. These disastrous explosions may be set off for the reason to break rocks which further will help in the formation of tunnels for roads, railroads, subways, or mines. These explosions, however, does not cause high and strong seismic waves. One may not even feel them. The intensity of an earthquake is the thing which matters a lot. Sometimes these seismic waves occur at the time of mine collapse of roofs and walls. These can sometimes be felt or sometimes cannot be felt by people who are near the mine.

By: Prerana Sharma
Content: http://www.geo.mtu.edu/UPSeis/why.html