Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: Earthquakes physics
Geographic Hazards of Earthquakes
Many geographic and environmental hazards constantly affect and alter the world in which we live. One of the most unpredictable natural disasters to occur is an earthquake. According to Merriam-Webster Collegiate Dictionary, an earthquake is "a shaking or trembling of the earth that is volcanic or tectonic in origin." However, the physical causes, economic and social effects, and costs go far beyond just that dictionary definition.
A phenomenon known as tectonic forces is generally what causes an earthquake. Tectonic plates, large sections of the earth's lithosphere, are in gradual, constant motion. As these plates move in opposing directions, areas of subduction, where plates come in contact and slide beneath one another, cause an upward shift in a portion of the earth's crust. Earthquakes generally occur along these fractures of the lithosphere, or faults.
Using a seismograph and a formula known as the Richter Scale, scientists measure an earthquake's magnitude. This scale, though it has no specific upper limit, generally ranges from about 1.5, indicating the smallest quake that can be felt, to about 9.0, indicating a severely devastating earthquake. The Richter Scale expresses only an earthquake's seismic strength, not the damage it causes.
The effects of an earthquake vary greatly and have numerous contributing factors. A magnitude 8.0 quake centered beneath downtown Los Angeles would do much more damage than a quake of equal strength centered beneath a desolate area of Alaska. Population densities, the design and structure of buildings and roads, and a general preparedness greatly determine the amount of damage any earthquake will do. A highly populated or urbanized area is much more susceptible to widespread damage from an earthquake than a sparsely populated area, simply because there is more to damage. Some of the devastating effects of earthquakes can include structural damage to buildings, buckling of roadways and bridges, shattering glass, fires, or tsunamis (tidal waves).
Earthquakes can be very costly to both human life and material things. Cities located along major faults have begun enforcing stricter building codes to help ensure less structural damage when an earthquake occurs. Structural reinforcements of skyscrapers and other buildings assist in preventing widespread monetary loss and loss of life. For those living in areas of major earthquake activity, knowing what to expect and how to react is also crucial in lessening the devastation of a high magnitude earthquake.
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.
Earthquakes happen about 20,000 times a year worldwide. They can destroy almost anything.In 2011, Japan had 9.1 magnitude earthquake, close to the highest magnitude of 9.2 in Alaska. They suffered tremendous damage from such a strong earthquake. The year before Haiti suffered from a 7.0 magnitude earthquake, still quite high compared to small tremors at magnitude 0-2. Japan recovered and rebuilt much faster than haiti did though. Haiti isn't even quite done recovering yet. The earthquakes had such different effects on the countries because of their economy, the condition of their people, and population rates.
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).
Earthquakes in California are certainly not a surprise. What is a surprise is their unpredictability and randomness. Geologists say there is roughly a 50 percent chance that a magnitude 8 or more quake will hit the Los Angeles area sometime over the next 30 years. And, over the past twenty years, the Los Angeles area has witnessed several earthquakes, and in particular, two that were quite devastating; the 1971 San Fernando earthquake, and the January 17, 1994, Northridge Earthquake. Given the certainty that earthquakes will occur, they still seem to come as a surprise, and leave many communities unprepared to deal with their aftermath.
Primary impacts are the result of the ground shaking causing buildings to collaspe. This than results in the secondary impacts which are usually tsunamis, fires, landslides and other catastrophic events. Tsunamis, a huge wave of water, are one of the worse things human life can face after an earthquake as they are known to destroy absolutely everything in there path. Landslides, another huge destruction, is often known to be worse than the earthquake itself. These can cause whole cities to be completely destroyed as in Alaska, Turnagain Heights. Fires also cause a huge path of destruction. Broken gas lines set gas free making one little spark cause an inferno. An example of this would be the great earthquake of 1906 in San Fransisco which caused 90% fire damage among everything
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.
During the years of 1811-1812 three earthquakes occurred near the small town of New Madrid, Missouri. Based on the on the Richter scale the magnitudes of each or these earthquakes measured at a 7.0 or higher. These earthquakes were felt as far away as Boston, Hartford, and New Orleans. The damage caused by these earthquakes went as far as Cincinnati, Ohio and St.Louis Missouri. These earthquakes are known as the New Madrid Earthquakes.
benchmark for the future, and integrated investigation into the effects of earthquakes in the U.S.
The earthquake was caused by a strike-slip fault. A strike-slip fault is when the rupture is almost nearly vertical movement. During an earthquake, they slide past each other.
They are the earth’s crust; they move very slowly every year. As the tectonic plates slide over each other they cause earthquakes. Earthquakes produce various damaging effects this includes damage to structures of buildings, bridges and other standing formations which then...
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.
The basic science is pretty straightforward. The earth lurches from time to time because its outer shell is broken into huge, solid plates floating on a layer of molten rock that has the consistency of Silly Putty. These tectonic plates are constantly jostling each other, like rafts crowded into a small pond, and its along the boundaries where they meet that most quakes are born.
Taher, R. (2011). General recommendations for improved building practices in earthquake and hurricane prone areas. San Francisco, CA: Architecture for Humanity Retrieved from
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).