The effects of an earthquake range from mild to severe and include structural damage, damaged gas lines, tidal waves, fires, avalanches and flooding. The amount of damage an earthquake can cause depends greatly on the size of the earthquake. The 1994 earthquake in Northridge, California was a magnitude 6.7, caused 57 deaths, 5,000 injuries, and damaged homes, bridges and structures.
The amount of structural damage that can occur during an earthquake with a magnitude of 4.0 or higher depends on the construction of the structure. In California, many newer structures are specifically designed to withstand earthquakes, but some of the older buildings do not respond well to ground motions.
Earthquakes are defined as an intense shaking of the ground that occurs when a fracture in the earth's rocks causes the ground to shift. Rock fractures are also referred to as faults, which is where the term fault line developed. Fault lines are the specific locations of each fault, and they are continually studied and monitored by earth scientists.
Earthquakes occur at a moment's notice, and it is important for homeowners to be as prepared as possible in the event of a severe quake. This means keeping an earthquake kit with flashlights, water, batteries and spare food, as well as taking steps to ensure the home structure is secure.