Essay On Seismic Waves

558 Words2 Pages
bulb-icon

Recommended: Effects of earthquake Essay

When the build up of potential energy around a fault line becomes too great, the two blocks of rock slip suddenly past each other as the built-up energy is transformed into kinetic energy. As the blocks of rock are jolted violently an initial shock wave radiates from the area where the slip occurred, also known as the focus. As the rocks continue to slip back and forth, more shock waves are sent out. After the initial slip occurred at a depth of around 6km on the Port Hills Fault, the rupture spread upwards and then towards the northwest, thereby focusing all the energy of the earthquake towards the city.

There are four different types of seismic waves: Primary (P), Secondary (S), Love (L) and Raleigh (R). P waves are the first waves to reach recording stations, which is why they are called primary waves. They travel at approximately 20,000km/h and are a push-pull wave, which means they stretch and squeeze rocks as they pass through. S waves are slower than P waves, travelling at 10,000km/h, therefore arriving after P waves at the recording station. They have larger amplitudes th...

Show More
Related

  • The Sub-Surface of the Planet: Observations verses Inferences

    784 Words  | 2 Pages

    could be used to explain and illustrate that previous theories were not entirely correct (Merali and Skinner, 2009, p.253). Through the analyzation of arrival times of these waves, Oldham had drawn an conclusion that p waves and s waves react differently in terms of being refracted, reflected or absorbed depending on the state of the material as shown in Figure 1.(Tarbuck, Lutgens, Tasa, 2013, p.143). Oldham had developed this theory of the Earth not being the same state due to these effects of seismic discontinuity which are shown in Figure 1., consisting of refraction, reflection and absorption. The changes that are displayed from this idea are; the speed of the waves due to a refraction occu...

    Read More

  • Major Earthquakes are Inevitable in Indiana’s Future

    1293 Words  | 3 Pages

    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...

    Read More

  • Pulse Wave Analysis Essay

    1900 Words  | 4 Pages

    This chapter provides some insight into pulse wave analysis and its relation to arterial diseases. The shape of the arterial pulse wave is an augmentation of the forward traveling wave with the reflected wave. The amount of wave reflection is dependent on the arterial wall properties such as arterial stiffness and is expressed in terms of Augmentation Index. This approach has been studied extensively using various measuring techniques, all of which have respective advantages and disadvantages. The purpose of PWA can be seen in the section describing the medical conditions that affect the wave shape. The discussion is included to assist the reader in understanding the purpose of pulse wave analysis.

    Read More

  • San Andreas Fault Theory

    916 Words  | 2 Pages

    Since record keeping began, sometime in the 18th century, there have been 13 major earthquakes along the San Andreas Fault. However, radiocarbon dating has proved that earthquakes have been happening along the fault for thousands of years. The earliest recorded earthquake happened on July 28, 1769, and was experienced by Spanish explorer Gaspar de Portola while he camped along a small lake he named “San Andreas Lake”. Other notable early earthquakes occurred in 1836, 1838, 1865, 1868, and 1890. Unfortunately, there is no seismographic data recorded for these early earthquakes since it was not until 1887 that seismographs began being used in the United

    Read More

  • Analysis Of The Great Wave By Katsushika Hokusai

    1041 Words  | 3 Pages

    Over the course of Japanese history, arguably, no artist is more famous for their works than Katsushika Hokusai. During his 88 years of life, he produced over 30,000 pieces of artwork, and heavily influenced Western styles of art. His most famous piece was created around 1831, a Japanese styled piece titled, The Great Wave off Kanagawa. This piece has stood as a defining piece of artwork in the Japanese culture for over 180 years, analyzed by students and authors for the interpretations filling the paper. The relationship between Hokusai’s painting has directly affected the Western point of view of Japanese style. The English author, Herbert Read’s novel interprets the painting distinctly differently from a Japanese point, American poet,

    Read More

  • The San Francisco Earthquake Of 1906

    986 Words  | 2 Pages

    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...

    Read More

  • Annual Temperature Of San Francisco

    973 Words  | 2 Pages

    ...tectonic movement of the plates, the stress forms along the fault and ultimately releases as an earthquake. On the pacific plate, Transform boundary along with the San Andreas fault. Transform-fault boundaries is when two plates that slide horizontally past another. Transform boundaries are usually found on ocean floor, but a few occur on the land. San Andreas fault zone is a transform fault, which connects East Pacific rise, in the south a divergent boundary, with South Gorda-Juan de Fuca-Explorer Ridge, yet another divergent boundary to the North. Ultimately because it’s a transform boundary, convergent boundary is strike-slipping past each of the plates in order to release pressure. As the San Andreas Fault is prime transform boundary between the North American Plate and the Pacific Plate, the Hayward Fault assumes a share of the total motion between the plates.

    Read More

  • The Northridge California Earthquake

    1129 Words  | 3 Pages

    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...

    Read More

  • The Great Alaska Earthquake

    921 Words  | 2 Pages

    Additionally, this earthquake occurred on a thrust fault. This fault was a subduction zone slip which occurred primarily beneath the ocean were the Pacific plate plunges underneath the North American plate. This sudden upward movement of the sea floor along the rupturing fault generated a massive tsunami. This vertical deformation

    Read More

  • San Andrea Fault

    473 Words  | 1 Pages

    The San Andreas Fault is a geologic fault zone between two tectonic plates that runs from San Francisco south to San Diego in California. It is an area of frequent earthquakes caused by the plates sliding past each other. It is so called because it runs along the San Andreas Valley.

    Read More

  • Earthquake Essay

    1824 Words  | 4 Pages

    The 6.7 magnitude earthquake was felt throughout most of southern California and as far away as Utah and Mexico with a max acceleration of 1.0g in several different areas and the highest at Tarzana with a recorded value of 1.8g. The earthquake also deformed over 1500 square miles of the Earth’s crust, forcing the surface upward in a dome shape. The Susana Mountains sustained the most soil deformation with an uplift of around 15cm causing numerous rockslides, blocking many roadways. Soil liquefaction was observed in the Simi Valley area and other parts of the Los Angeles Basin. After all the term oil ended the preliminary cost estimate of damage was between 15 and 20 billion U.S. dollars. Today, Geologists remain to search for thrust faults throughout the southern California area by using a 3 dimensional modeling system to view folds and upli...

    Read More

  • Tectonics Theory Essay

    1021 Words  | 3 Pages

    Understanding the plate tectonics theory is very important, especially when investigating natural disasters like earthquakes, and volcanic eruptions. It is also gives scientists the ability to understand how mountains were formed between two tectonic plates. There are three types of interactions between plate boundaries: convergent, divergent and transform. Looking back at the history of these three different interactions, earthquakes, like the one in Haiti, volcanic eruptions, like at Mount St. Helens, and the creation of mountain belts, like the Mid-Atlantic Oceanic ridge, gives information on future consequences of tectonic movement, and what can happen when the plates interact with each other.

    Read More

  • Earthquake Engineering

    903 Words  | 2 Pages

    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.

    Read More

  • Earthquakes Hazards And Disaster

    1192 Words  | 3 Pages

    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).

    Read More

  • Essay On Earthquake Prediction

    1552 Words  | 4 Pages

    Question: Research the current state of earthquake prediction. Have we made any progress in recent years? Are other countries making progress? How far away are seismologists from being able to accurately predict earthquakes? Go beyond what was discussed in class.

    Read More

More about Essay On Seismic Waves

Open Document