Shaking it up
What are Earthquakes?
Earthquakes are a natural phenomena that occur constantly. They occur when sections of the Earth's crust, known as tectonic plates, shift. Tectonic plates are always in motion, pushing and sliding against each other, and this causes earthquakes to occur all the time.
Tectonic Plates and Faults
Tectonic plates are giant masses of the Earth crust that shift along the mantel layer. When two tectonic plates push against each other, one will end up going above the other. The plate that is forced down slowly goes into the Earth's mantel where it is turned into magma. The boundaries between tectonic plates are called faults. This is typically the location where most earthquakes take place. When the tectonic plates move along the fault, earthquakes occur.
Earthquakes are caused by the sudden rapid release of stored potential energy. This potential energy gets stored when one tectonic plate is pressed against another. When the rocks can no longer remain in place and the rocks shift, the energy is released and transformed into kinetic energy.
When the potential energy is converted into kinetic energy, the ground starts to vibrate. The vibrations are also known as seismic waves and travel outward in all directions from the focus of the earthquake. This is similar to the way water acts when you drop an object into it.
Magnitude is the strength of the vibrations of an earthquake. The Richter scale measures how powerful an earthquake is. The measurements of the scale are logarithmic. Most of the time the scale is thought to begin at 1 and end at 10, but there are no limits on the Richter scale as to how powerful an earthquake is. Earthquakes under 3 typically cannot be felt and are frequent occurrences. Earthquakes rated at 7 or higher have the potential to cause widespread destruction.