How Do You Know If There Is an Earthquake Happening?

The sensations of an earthquake differ depending on the distance from and magnitude of the event. Large earthquakes, when experienced close to the epicenter, involve violent ground jolts and shaking; farther away a large earthquake feels more like a gentle bump and a rolling-ground sensation. Small quakes, in contrast, feature smaller jolts and fewer shakes at close range, and those who are farther away may not feel anything.

High-magnitude earthquakes experienced at close proximity represent a serious danger to people and property. The ground movements during the event often knock people off their feet, damage or destroy building foundations and supports, and rupture supply and removal lines for water, gas, sewage and electricity. The contents of surviving structures are often in serious disarray, as items on shelves and in cabinets fall to the floor during the episode.

The U.S. Geological Survey, an agency of the U.S. Department of the Interior, tracks earthquakes that occur in the United States. To this end, the agency provides the "Did You Feel It" reporting system on its main website. Anyone who experiences ground shaking is encouraged to file a free report with the USGS to improve earthquake warning and notification.

During an earthquake, the best method of protecting yourself is to stay indoors and shelter under a heavy object, holding on during the shaking, according to the U.S. Federal Emergency Management Agency. Covering the head and neck is also important to avoid injury from falling objects.