EARTHQUAKES
Objective: To define and discuss earthquakes and its effects.
Earthquakes are a major catastrophe and can be a big threat to human lives. To understand earthquakes you must have a clear definition, know its mechanisms, be able to recognize the size and dynamics and understand its effects:
I. Definition of Earthquake
a. Earthquake
b. Tsunamis
c. Landslides
d. Volcanoes
II. Mechanism
a. Faults
b. Seismic Waves
c. Aftershocks
III. Size
a. Strength
b. Classification of Seismic Waves
1. P (compressional)
2. S (Shear)
c. Logarithm
d. Intensity
IV. Dynamics
a. Statistics
b. Occurrence Sites
V. Effects
a. Destruction
b. Building Codes
VI. Prediction
a. Scientific basis
b. Identify plate boundaries
VII. Summary
In order to define earthquake properly many things are taken into consideration. First of all an earthquake is basically defined as a naturally induced shaking of the ground, caused by fracture of rock within the Earth. The results of an earthquake are sliding rocks past one another along a geological fault. Earthquakes are one of the deadliest of natural catastrophes. In the 20th century alone the average annual death toll is about 20,000 people.
As a result of earthquakes tsunamis, landslides and volcanoes are formed. Tsunamis are characterized as large waves in oceans as well as seiches, which are similar waves in lakes. Landslides are simply a downward movement of rocks due to gravity. Lastly volcanoes are hills or mountains formed from rock fragments ejected through a vent. Earthquakes sometimes cause th...
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...iewing size, strength, classification, logarithm and intensity are observed. Along with size the dynamics of quakes are reviewed. The dynamics consist of the statistics and occurrence sites. Effects of earthquakes are a lot of destruction. For this reason many countries have adopted special building codes with seismic provisions. Lastly predictions of quakes have been and still are being studied as a way of preparing for this catastrophe. This would save countries a lot of money. Earthquakes can be a horrific experience but its something that can’t be avoided all scientist can to is try to find a way to prepare for it.
BIBLIOGRAPHY
Naeim, Farzad Design of Seismic Isolated Structures: From Theory to Practice Wiley, John & Sons INC., March 1999
Prager, Ellen Furious Earth: The Science and Nature of Earthquakes, Volcanoes and Tsunamis McGraw Hill, November 1999
Sieh, Kerry E.; Levay, Simon The Earth in Turmoil: Earthquakes, Volcanoes, and Their Impact W.H. Freeman company, July 1999
Simon, Seymour Earthquakes Morrow, William & Co., March 1995
Thompson, Graham R.; Turk Jonathan Earth Science and the Environment 2nd edition Saunders College P
Earthquakes are a natural part of the Earth’s evolution. Scientific evidence leads many geologists to believe that all of the land on Earth was at one point in time connected. Because of plate tectonic movements or earthquakes, continental drift occurred separating the one massive piece of land in to the seven major continents today. Further evidence supports this theory, starting with the Mid-Atlantic ridge, a large mass of plate tectonics, which are increasing the size of the Atlantic Ocean while shrinking the Pacific. Some scientists believe that the major plate moveme...
Earthquakes are frequent but most of the time aren’t very big on the Richter Scale. Statistics and research show that there are earthquakes happening constantly, but most of the time are impossible to feel unless they are above a 3 on the Richter Scale (see source7).
Heller, Arnie. "The 1906 San Francisco Earthquake." Science & Technology (2006): 4-12. Web. 8 May 2014.
The science of the natural disaster has baffled many, but from studying the San Francisco earthquake, scientists have made a number of important discoveries and they have a better understanding of earthquakes. At 5:12 on a fateful April morning in 1906, the mammoth Pacific and North American plates sheared at an incredible twenty-one feet along the San Andreas fault, surpassing the annual average of two inches (“San Francisco Earthquake of 1906”)(“The Great 1906 Earthquake and Fires”). The shearing caused a loud rumble in the Californian city of San Francisco. A few seconds later, the destructive earthquake occurred. The ground shifted at almost five feet per second, and the shaking could be felt all the way from southern Oregon to southern Los Angeles to central Nevada (“Quick”)(“The Great 1906 San Francisco Earthquake”). Moreover, the earthquake could be recorded on a seismograph in Capetown, South Africa, an astounding 10,236 miles away from San Francisco (“San Francisco ea...
Earthquakes are best described as a shaking or vibration of the ground caused by breaking of rock. Sometimes they are very strong and other times you would hardly notice them. This shaking occurs when stress that builds up in the crust is suddenly released as the crust breaks free and/or slides against the other pieces of crust. Earthquakes may also be thought of as the breaking of a popsicle stick by applying pressure to both ends at the same time. Should you try this experiment , you will feel the pressure build up as you apply more force until the stick snaps. When the stick snaps you will feel an instant of pain at your fingers as the stress reduces and energy waves move throughout the stick. When the earth's crust is placed under similar types of stress, binding as the stress builds, it will also snap and release the energy into the surrounding rocks, 'ooch'. Thinking about earthquakes will become more clear if you try another experiment.
From studying the science behind the San Francisco earthquake, scientists have made a number of important discoveries involving how earthquakes function. At 5:12 on a fateful April morning in 1906, the mammoth Pacific and North American plates sheared each other at an incredible twenty-one feet along the San Andreas fault, surpassing the annual average of two inches (“San Francisco Earthquake of 1906”) (“The Great 1906 Earthquake and Fires”). A few seconds later, the destructive earthquake occurred. The ground shifted at almost five feet per second, and the shaking could be felt all the way from southern Oregon to southern Los Angeles to central Nevada (“Quick”) (“The Great 1906 San Francisco Earthquake”). In fact, the earthquake could be registered in a seismograph on Capetown, South Africa, an astounding 10,236 miles away...
Problem Statement: Earthquakes are a natual part of the environment. They do,however,cause devistating effect on the environment. Since Earthquakes can not be avoided, maybe there is a way to determine when they are going to occur so precautions can be taken to get people to safety and protect as much of
Before examining the Northridge event, understanding the naturally occurring hazard that is an earthquake will help to better understand exactly what happened and why it was such an important geological event. With four distinct layers, two layers, the crust and upper portion of the mantle, compose the skin that is the surface layer of the Earth. The crust is not a single, continuous piece. It is actually several different pieces, or plates, that come together to form the puzzle that comprises the surface of the Earth. These plates are in constant motion rubbing against one another. These areas, known as fault lines, where the plates rub up against one another have spots where one plate ”gets stuck while the rest of the plate keeps moving. When the plate has moved far enough, the edges unstick and is how most of the earthquakes around the world occur” (Wald, 2012). The energy stored from the friction of the two plate...
benchmark for the future, and integrated investigation into the effects of earthquakes in the U.S.
Mr. Adams describes the San Francisco earthquake as his most profound human suffering experience because the horror of shaking floors, parts of his mom’s house collapse to the floor, and got a broken nose from stumbling into a brick wall (Ansel Adams & The 1906 Earthquake 2008). Earthquakes are part of natural disasters of the earth and normally caused by shaking ground and rapid movement of one block of rock slipping past another a long fractures in the earth crust called faults. Faults that are usually locked excluding abrupt movements, which slippage creates an earthquake (Lutgens, F. & Tarbuck, E.
"The Great Quake: 1906-2006 / Rising from the Ashes." SFGate. N.p., n.d. Web. 10 May 2014.
Earthquakes are vibrations felt at the surface of the earth which are caused by disturbances of the energy in the earth's interior. These vibrations are known as seismic waves. (Skinner Robinson McVerry 1) There are different type sof seisimc waves such as Primary (P) waves, whcih travel the fastest, Secondary (S) waves which cause the earth to vibrate vertically, Surface (L) waves. P and S waves are "affected by changes in the density and the rigidity of the materials through which they pass." (Columbia Encyclopedia) Earthquakes vary in their intensity and duration. Often times they are strong enough to cause massive destriction. Tall buildings often suffer as a result of these natural disasters. In recent years this has become a larger and larger threat with both the number of large buildings, and their number of occupants increasing. In an effort to try to minimize the damage caused by earthquakes many some engineers focus primarily on designing and constructing earthquake resistant buildings. Earthquake engineers have gathered much of their information from analyzing past earthquakes, and learning which buildings can and can't withstand the tremors. The goals of these engineers is to design buildings that can withstand moderate earthquakes and obtain minimal damage, and that the buildings will not collapse lowering the probability of human deaths.
It was a beautiful day like any other with the clear blue sky and the
Robinson, Andrew,; Earth Shock: Hurricanes, Volcanoes, Earthquakes, Tornadoes and Other Forces of Nature; Themes & Hudson Ltd., September 1993
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).