"A broadly satisfying explanation of the majority of earthquakes can be given in terms of what is called plate tectonics. The basic idea is that the Earth's outermost part also called the lithosphere consists of several large and fairly stable slabs of solid and relatively rigid rock called plates" (Branely 154).

These plates continuously move pushing and rubbing against each other.

Since the earliest of time people have been looking for an explanation for earthquakes. The people of Maori in New Zealand believed the god of earthquakes, Ruaumoko is said to have pressed into the earthquake as his mother turned face downward while feeding him. According to the legend, he has been growling and spitting fire ever since. Aristotle believed that "mild earthquakes were caused by wind escaping from caves within the bowels of the earth and severe shocks were by gales that found their way into great subterranean caverns" (Matthys 87). However, with modern technology we found that what actually causes earthquakes is tectonic plates which on average move only two inches per year they are driven by convection currents which is the upward movemen

t of heated particles rising from the earth's molten core. As the plates are driven against each other one will try to and eventually will slip underneath the other. When plates move quickly an earthquake is the result.

volcano is nothing more then a vent in the earth's crust. One good example of a volcano was Mt.St. Helens. In March 1980 a few earthquakes near Mt.St. Helens began a

Earthquakes and volcanoes often, but by no means always, accompany each other. A volcanic eruption is at a point of weakness in the earth's crust. It starts when a movement, often due to the shaking of an earthquake, opens a crack in the crust: a

"Because the size of earthquakes varies enormously, the amplitudes of the ground motions differ by factors of thousands from earthquake to earthquake. It is therefore most convenient to compress the range of wave amplitudes measured on seismographs using some mathematical device" (Bolt 118).

The estimated magnitude was 8.25, and lasted 40 seconds, but the shaking continued for 10 minutes doing the greatest damage.

Some common words found in the essay are:
Maori Zealand, California Matthys, Chang Heng, Bay Japan, Aegean Sea, , Richter California, Dr Pignataro, Harry Truman, MtSt Helens, sea wave, water waves, san francisco, earthquake shaking, earth's crust, mtst helens,
Approximate Word count = 1182
Approximate Pages = 5 (250 words per page double spaced)