Earthquakes II

Throughout the history of the earth, earthquakes have been recorded for their unbelievable
destructive forces.  Earthquakes can and do often strike without warning. They have the capability to level large cities and kill thousands of innocent people.   Not only can earthquakes bring harm to our communities through these methods of destruction, but they can also cause millions of dollars worth of property damage to the areas they destroy.  These natural disasters have killed thousands in the U.S. alone since 1900.(National Geographic)The most famous earthquake in U.S. history is that of 1906 in San Francisco California. An estimated 3000 people lost their lives on April 18^th 1906. It is difficult to believe that so much damage was done as a result of 45-60 seconds of shaking. The damage done was not only a result of the earthquake. The seismic disturbance also caused an enormous fire to break out throughout the city. (U.S. Geological Survey) It is important to understand good safety precautions if you find yourself in an earthquake situation. If you are indoors drop to the ground and seek immediate cover; Preferably under a table or piece of furniture. If this is not possible cover your head and crouch in the corner of the room or building. As with nearly all natural disasters It is important to say away from glass and windows. Aside from popular belief it is only a good idea to stay in a doorway if you know it is strongly supported and remain indoors until the shaking stops. (FEMA Department of Homeland Security) 

Corey Dwyer

National Geographic (2011, February.) Earthquakes. retrieved February 20 from  http://environment.nationalgeographic.com/environment/natural-disasters/earthquake-profile.html

Department of Homeland Security (2011, February.) What to Do During an Earthquake. retrieved February 20 from http://www.fema.gov/hazard/earthquake/eq_during.shtm

EHP Web Team (2009, January.) The Great 1906 San Francisco Quake. retrieved February 20 from http://earthquake.usgs.gov/regional/nca/1906/18april/index.php

Earthquakes

Perhaps one of the most frightening and destructive natural disasters an individual can find themselves in is an earthquake. Earthquakes are centered on the scientific theory of plate tectonics. The idea of plate tectonics begins with the earth's lithosphere including the crust which is made up of constantly moving plates. These large plates move at an extremely slow rate of speed building up pressure when they move over, or grind against one another. Once enough pressure is built up over time the energy is released in the form of an earthquake. (Sebeck, 2004)

 When these natural disasters occur in populated areas the result can be large loss of human life and great property destruction. The study of these phenomena is relatively new as far as the science world is concerned. Today buildings are being structurally designed in ways that will prevent them from falling over in the event of an earthquake. When an earthquake occurs the energy released is in the form of seismic waves. These waves are used to determine the strength of the earthquake. (U.S. Search and Rescue Task Force, 2000) Earthquakes most often occur along faults. A fault can be defined as "a three-dimensional surface within the planet Earth. At the fault, rocks have broken. The rocks on one side of the fault have moved past the rocks on the other side. In contrast, a fault line is a line that stretches along the ground. The fault line is where the fault cuts the Earth's surface." (U.S. Geologic Survey, 2003) perhaps the most famous earthquake in U.S. history occurred in 1906 along the San Andreas Fault. The result of the earthquake left California in ruins killing over 700 people.

As mentioned before the science of plate tectonics and earthquakes is relatively new. In order to keep people safe it is important that we continue to make advancements in earthquake predicting technology. Ideally we would like to be able to predict an earthquake early enough to allow proper disaster response thus minimizing potential loss of life and property.  However the prediction of an earthquake is a very difficult thing to do. Today scientists study past earthquakes to try to determine when future earthquakes may occur. However, this method is not the most practical. For example, between 1836 and 1911 four 6.8 or higher magnitude earthquakes occurred in the San Francisco are along with many earthquakes between 6 and 6.5. Since 1911 to date no earthquakes above a magnitude of six have occurred in the San Francisco area. (U.S. Search and Rescue Task Force, 2000)

Corey Dwyer

Sebeck, Julie. (2005, April.) Plate Tectonics. Retrieved February 6 2011 from http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html

Lebov, Steven. (2000) Earthquakes. Retrieved February 6 2011 from http://www.ussartf.org/earthquakes.htm

USGS.gov (2003) Where are the Fault Lines in the United States? Retrieved February 6 2011 from http://earthquake.usgs.gov/learn/topics/faults_east.php