| Earthquakes
happen when the Earth's continental plates can not take the stress
of pushing on each other and they give way. All of the energy that
the plates were storing up while they were pushing on each other is
released all at one time. The energy released moves in a wave away
from the source, epicenter, causing the earth to tremble and shake.
Hundreds of tiny earthquakes happen every day around the world. By
itself, Southern California has about 10,000 earthquakes every year.
Some of them are so light that no one know that they happen except
the scientists that are watching for them. Only 15-20 of those earthquakes
are strong enough for people to feel. Stronger earthquakes don't happen
as often, but they cause a lot of damage to the land and man made
structures. |
