Earthquaque Assignment - Sci 205 Essay

Earthquakes Assignment Assessment
Diana M. Cintron
Sci/205
April 11, 2010
Dr. Dillon, PhD

Earthquake Assignment Assessment The Earth’s outer shell is a set of plates called plate tectonics. According to [About.com – Geology] the definition of tectonic is a large scale structure. The plates are constantly changing positions and geologic evidence shows that they have moved the same way in the past. The movement is very slow no more than a centimeter a year. The movement of the plates is divided in three ways: they move together (converge), the move apart (diverge), or they move past each other [About.com – Geology]. “Earthquakes occur along faults, where huge blocks of rock are grinding past each other. Tectonic motions produce directional pressure, which causes rocks on either side of a large fracture to move past each other. The movement is rarely smooth; usually the blocks stick because of friction, which slows their movement. Eventually, the friction is overcome and the blocks slip abruptly, releasing pent-up energy with a huge “snap”—an earthquake” (The Plate Tectonic Model – Page 107).

Plates diverge at volcanic zones by the ocean basins. These are long huge cracks were lava rises from below and freezes into the Lithosphere (About.com – Geology).
In which plates move past each other is call a transform boundary. These are not that common as the converge or diverge plates and the most common one is the San Andreas fault of California [About.com – Geology]. The Pacific Coast of the US is the region most susceptible to earthquakes [essortment.com]. Recently, there has been more activity specifically in the Caribbean plate (Haiti), the West Coast of South America (Chile), the Pacific Islands and other areas in the Asia continent. As I understand it when there is one shift in the plates this creates a global shifting to the other plates in