Review of Literature
I. Introduction to Earthquakes
An earthquake is the shaking of the ground caused by sudden release of energy inside the earth's crust. It's the breaking and moving of tectonic plates along a fault line. Earthquakes can range in size from weak where we don't feel them to extremely violent where they actually thow people around and destroy cities.
An earthquake occurs when there is a shaking of the Earth, caused by a buildup of energy in volcanic or tectonic form (“Earthquakes”). Essentially, an earthquake results from sections of the Earth moving, causing slippage. When two chunks of the Earth slip past each other, the point at which this happens is called the fault plane. In fact, an earthquake begins in the hypocenter beneath the Earth’s surface. Next, located right above the hypocenter is the epicenter (Wald). And finally, the main, and most important thing to remember about earthquakes is that they are random, and extremely hard to predict (“Earthquakes”).
Powerful forces of nature can cause destruction to lives and property. While the continuing study of earthquakes and volcanoes helps us determine and better understand their powers, they continue to be natural phenomena that we need to learn even more about. Even with many differences in these two forces of nature, it is interesting that they also have commonalities. There are numerous similarities and differences between earthquakes and volcanoes.
An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter.
Figure 1; Showing the fault plane, point of origination and epicenter
2 Earthquake Geophysics:
The earth has the following structure, a 30 km thick crust, a 2900 km thick mantle, and a radius of 3470 km core, which forms the total radius 6370 km.
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 the ground and rapid movement of one block of rock slipping past another along fractures in the earth crust called faults. Faults are usually locked excluding abrupt movements with slippage that create earthquakes (Lutgens, F. & Tarbuck,
Earthquakes, by Webster’s dictionary definition, are, “a shaking or trembling of the earth that is volcanic or tectonic in origin.” World Book Encyclopedia reports scientists believe that more than 8,000 earthquakes occur each day without causing damage. A little more than 1,000 each year are strong enough to be felt. Earthquakes occur in the general sense, anywhere on land. Other earthquakes go by different names, such as volcanic eruptions and tsunamis, large tidal wave storms that occur underwater, primarily in the Pacific Ocean.
This is one of the most commonly asked questions around the world. Earthquakes are very common because the Earth’s tectonic plates are constantly moving, because they are constantly moving earthquakes are happening quite often across the globe. Statistics show that over 1 million occur each year worldwide (see source 9), but earthquakes don’t have to be felt for them to have occurred. Statistics prove that 1 100 000 earthquakes happen per year worldwide that can’t be felt by humans. Statistics show that about 11 670 earthquakes occur that can be felt in the area of occurrence and sometimes even further
An earthquake is a vibration of the Earths surface that follows a release of energy in the Earths crust. There are various ways this energy is released. Manmade explosions, dislocation of segments of the crust or volcanic eruptions are all triggers for an Earthquake; however, most are caused by a slippage of faults. A fault is a fracture in the Earths crust along which two blocks of the crust have slipped within one another. These faults are grouped into three categories (normal, thrust and strike-slip) and are located all over the Earth.
Earthquakes are one of the most mysterious natural disasters that we deal with to his day. That is the thriller of earthquakes, is the fact that they are so strange and bizarre that it keeps us guessing when the next one is to come. The San Andreas Fault earthquake is the most mysterious, dangerous, and soon to come earthquakes that we still do not necessarily have a date on towards when it will happen.
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...