1. By Trinidad Arroyo

3. This gradual accumulation and release of stress and strain is now referred to as the "elastic rebound theory" of earthquakes. Most earthquakes are the result of the sudden elastic rebound of previously stored energy. If a stretched rubber band is broken or cut, elastic energy stored in the rubber band during the stretching will suddenly be released. Similarly, the crust of the earth can gradually store elastic stress that is released suddenly during an earthquake.

4.  Fault is a break in the Earth's crust caused by movement of rock. Also known as Tension, Compression, and shearing. Tension: Pulls apart Compression: Pushes together Shearing: slides apart in opposite directions

5.  The focus (more correctly termed the hypocenter) of an earthquake is the point in the earth where the earthquake rupture or fault movement actually occurred. The point on the surface directly a bove the hypocenter is known as the epicenter.

6. o The epicenter is the point on the earth's surface vertically above the focus (or the hypocenter), point in the crust where a seismic rupture begins

7.  A smaller earthquake following the main shock of a large earthquake

8. p waves are formed when matter in the rocks is pushed together by the earth's movement. they can travel through solids and liquids.  the P waves which is known as the (primary or compression) waves are the first to arrive at the recording station, p waves are formed when matter in the rocks is pushed together by the earth's movement. they can travel through solids and liquids.  P-waves are faster then S- waves

9. this waves are also called the shear waves. these waves are formed by the sideways motion of matter, it can only travel through solids.  the S waves which is known as the (secondary )waves are the second waves to arrive at the recording station. this waves are also called the shear waves. these waves are formed by the sideways motion of matter, it can only travel through solids.

10. The following table gives intensities that are typically observed at locations near the epicenter of earthquakes of different magnitudes. Magnitude Typical Maximum Modified Mercalli Intensity 1.0 - 3.0 I 3.0 - 3.9 II - III 4.0 - 4.9 IV - V 5.0 - 5.9 VI - VII 6.0 - 6.9 VII - IX 7.0 and higher VIII or higher

11. The mercalli scale tells you how much damage the earthquake caused and the level of the intensity it is.