Earthquake Facts Unearthed

The bowels of the Earth are unpredictably volatile, and every now and then the force within tries to burst to the surface with devastating power. Why do earthquakes happen? This cataclysmic phenomenon is actually part of a natural geological process.

Earthquakes are caused by seismic waves that are produced by a sudden and massive release of energy from the surface of the Earth, the crust. Just one of a number of the Earth's layers (which includes the core), the crust is itself composed of several sections referred to as plates which are continuously moving, but at such a slow pace that any significant effect it would have will only be felt after several thousand years. Once in a while, a plate's motion against another one causes an energy buildup that is released at the plates' meeting point, known as the fault line. The resulting energy discharge is the reason for why do earthquakes happen.

Earthquake & Tsunami In Japan

The focal point is the area from which the accumulated energy that can cause an earthquake comes from. It is typically located at the shallow depths from the crust, and positioned right on its surface is the epicenter. It is from here that seismic waves radiate in every direction, traveling at a variety of rates depending on the features (mass, solidity, etc.) of whatever substance they run into throughout the crust. The waves move constantly, but they eventually grow weaker the farther away that they get from the focal point. Ultimately, the waves will ebb away once the energy that produced them has been exhausted.

While the seismic waves make their way through the crust, they carry such a massive quantity of energy along with them that whatever they pass through is affected by it, thus causing the strong trembling in the ground that typifies the occurrence of an earthquake. How powerful and how long the duration of the quake would depend on how strong the seismic waves are. A mild tremor might result in very minimal damages, whereas a very strong, very violent one would wreak major havoc, sending huge buildings crashing down and causing the very ground to break open. As this is happening, the seismic waves would also be causing the ground to reverberate or make noise, potentially contributing even greater amount of destruction to an already catastrophic quake.

There are also other factors which affect the event of an earthquake. For instance, a man-made explosion packing enough force can produce enough energy to cause a tremor. Also, as powerful as an earthquake is, it can also be caused by another powerful disaster, such as volcanic eruption. Somewhat in relation to this, just as significant as the matter of why do earthquakes happen is the matter of where. The majority of quakes that occur in the world (some 90% of them) usually happen in what is referred to as the "Pacific Ring of Fire," a 45 kilometer horseshoe-shaped area which has 452 volcanoes comprising 75% of all the active and dormant volcanoes in the world. And the occurrence of a quake can also trigger another natural cataclysm. For example, a quake that happens underground may also result in a tsunami.

Frightening and at the same time fascinating; the answers to the question of why do earthquakes happen fills us with awe as it does with dread. In a way, it puts us mere mortals in our place, reminding us that we are always under the malevolent mercy of this mighty planet that we exist upon.

Earthquake Facts Unearthed