Earthquakes rock our world
Earthquakes are no laughing matter. They are the result of vibrations in the Earth's outer crust. These vibrations are caused when underground rock slips. The Earth's crust is made of large plates of rock. Over time these layers of rock slowly move causing the plates to slip against each other. These tectonic type earthquakes occur in regions where the large plates border each other - the San Andreas Fault in California is a well known fault line. Earthquakes can also be caused by volcanic activity. These types of earthquakes are usually not as destructive as the earthquakes caused by shifting plates. In fact, earthquakes caused by volcanic activity can actually be beneficial since they often precede a major volcanic eruption and act as a warning that