are the shaking, rolling or sudden shock of the earths surface.
Earthquakes happen along "fault lines" in the earths
crust. Earthquakes can be felt over large areas although they usually
last less than one minute. Earthquakes cannot be predicted -- although
scientists are working on it!
Most of the time, you will notice an earthquake by the gentle shaking
of the ground. You may notice hanging plants swaying or objects
wobbling on shelves. Sometimes you may hear a low rumbling noise
or feel a sharp jolt. A survivor of the 1906 earthquake in San Francisco
said the sensation was like riding a bicycle down a long flight
intensity of an earthquake can be measured. One measurement is called
the Richter scale. Earthquakes below 4.0 on the Richter scale usually
do not cause damage, and earthquakes below 2.0 usually cant
be felt. Earthquakes over 5.0 on the scale can cause damage. A magnitude
6.0 earthquake is considered strong and a magnitude 7.0 is a major
earthquake. The Northridge Earthquake, which hit Southern California
in 1994, was magnitude 6.7.
Earthquakes are sometimes called temblors, quakes, shakers or seismic activity. The most important thing to remember during an earthquake is to DROP, COVER and HOLD ON. So remember to DROP to the floor and get under something for COVER and HOLD ON during the shaking.