Earthquake Intensities

The term earthquake comes from the Greek term for “shaking.” An earthquake is a visible rip across the Earth’s surface due to a release of energy and stored stress in the Earth’s crust and causes seismic waves. Earthquakes have been around since the time of the earliest civilizations. Earthquakes used to be compared to the “unrest of spiritual beings.” Specifically, Aristotle and the Ancient Greeks stated that earthquakes were the result of the “underground winds”. The earliest earthquakes were recorded by seismometers which calculate the waves generated by each earthquake. The original seismometer was the Wood – Anderson seismometer. When an earthquake would occur a structure would dangle and reflect light on an image. The image “drawn”

Geologists measure an earthquake using a seismometer. A seismogram is an earthquake record produced by a seismomemter. Pore pressure monitors record

I am glad that I live in Florida. This appreciation of my living quarters comes to me after comprehensive study of location and patterns of earthquakes that occur, firstly in the world and secondly in the United States.

“when a massive earthquake struck on 5th of February 62 CE. The quake measured 7.5 on the Richter scale and devastated the surrounding towns” (Pompeii).

A failure in the interior of the Earth’s crust is the cause of most earthquakes. Once the stress inside the crust grows beyond the strength for that location of the crust, a failure occurs within the crust and seismic waves, which we know as earthquakes, are radiated outward. It was once thought that this description of seismic activity was the cause for all earthquakes, but now seismologists know the way earthquakes form and start is a very diverse process. Most earthquakes are classified in the category of being brittle failures, which generate strong seismic waves; some earthquakes involve slow slip motion. There is also evidence to suggest that some earthquakes are more of a thermal process due to large amounts of heat generation, rather than large seismic activity. (Scholz 2002) Also, some earthquakes are not the result of faulting however, but caused by large landslides. In the early days of seismology, these differences were noticed qualitatively but the technology available during that time made it hard to accurately tell the difference. Before an earthquake takes place, there is a large buildup of potential energy. The energies involved in earthquakes can be described by the elastic strain energy W, plus the radiated energy Er, the energy mechanically dissipated during an earthquake, Eg and the thermal energy due to heat dissipation, Eh. Since this equation is a description of potential energies, the actual event of an

It is no secret that earthquakes are natural disasters that can have devastating consequences. Earthquakes are defined as “vibration of Earth produced by the rapid release of energy” (Lutgens and Tarbuck, 2014, p. 548). These vibrations are the result of seismic waves, which are emitted from the epicenter during an earthquake (Lutgens and Tarbuck, 2014, p. 191). The epicenter is defined as the “location on Earth’s surface that lies directly above the forced of an earthquake” (Lutgens and Tarbuck, 2014, p. 548). Seismic waves are not all the same. There are two types used to determine the location of the epicenter: P-waves and S-waves (New York State High School Regents Exam Prep Center, n.d.). According the the New York State High School Regents Exam Prep Center, P-waves, or primary waves, travel faster than S-waves and go through solids liquids and gases. They are compressional waves and are smaller than S-waves which are shear waves (Southern California Earthquake Center, n.d.). As a result of P-waves moving faster than S-waves, P-waves reach measuring devices more quickly than S-waves (New York State High School Regents Exam Prep Center, n.d.). According the the U.S. Geological Survey (2016), seismograph is used to “detect and record earthquakes” by using a hanging mass over an unmoving base, so the mass records on the base when the ground moves.

The year 2010 was an active year for earthquakes and other natural disasters, racking up a total of four earthquakes ranked 7.0 or higher. Two of these quakes were merely a month apart, and started the year in a very destructive way. The first was a 7.0 in Haiti, the second over 3,000 miles away in Chile, an 8.8. Though both ravaged their countries, one was decidedly more devastating than the other. Looking at the magnitudes of the quakes, you might think Chile received the worst of it, but after further inspection, you may not be so sure. While the magnitude of a quake can be a big factor in the corresponding effects, the infrastructure of the affected area plays an even larger role in the number of casualties and the amount of devastation that is experienced. This devastation is further increased in coastal areas due to the high likelihood of tsunamis shadowing high magnitude quakes.

Earthquakes is caused by the movement of tectonic plates under the Earth’s crust when they are pushed against each other. Earthquake is directly danger to everyone because the shakes can causes building to collapse and kill people. Building can be damage by shaking it a little. The cause of earthquakes have to deal with the geological fault, landslides, nuclear testing and volcanic activity. When a rock that is underground, breaks along a fault, an earthquake will happen. As the two parts of a rock rub against each other roughly, it is pushing against one another which causes pressure to build up. Sometime the earth has foreshocks which scientists can’t tell until the earthquakes get bigger and stronger because it varies from small earthquakes to big one. Mainshocks can continue for weeks, months, or even years after the mainshock. The earth has four major layers like inner core, outer core, mantle and crust. These pieces move slowly around and sliding past one another and bumping into each other. These are

Throughout the world, devastating earthquakes occur with little or no advance warning. Some of these earthquakes kill hundreds of people. If the times, magnitudes, and locations of these earthquakes could be accurately predicted, many lives could be saved. This document proposes a review of how monitoring geophysical precursors can help in the short-term prediction of earthquakes. The proposed review will discuss the physical principles behind the monitoring of three common precursors and evaluate how accurate each monitoring is in predicting earthquakes. Included in this proposal are my methods for gathering

Earthquakes are caused by the movements of the earth. Large blocks of stone called tectonic plates are constantly moving creating friction and stress with each other. These earthquakes then cause massive damage above the surface. There are three different types of earthquakes.

When we talk about earthquakes, we look at their causes based on plate movements. There are three types of movements: Convergent, Divergent and Transform faults. In a convergent scenario, during movement, one plate is forcefully lifted over another creating thrust. During a divergent movement, plates are forcefully separated apart from each other creating a rift zone. This type of movement usually occurs in oceanic floor where this is many new floor formations. The last is a transform fault, this is usually called the “strike-slip” because its movement is unlike the convergent or divergent scenario, it is a slip like movement that causes plates to move parallel to each other. When these types of movements occur, seismic magnitude is dependent on the scale of movement. However, we feel these earthquakes through waves, and each wave is specific to movement. There are generally three types waves: Primary wave (P), Secondary waves and surface waves (S). The surface waves are usually discarded in seismic focus; however, the P and S waves generate the most attention. P waves are also known as compressional waves and they are the first sign of earthquake at a seismic station where they travel through the earth’s crust at a rate of 1.5-8 km/s. As they travel, they shake the ground depending on the movement that they propagate. S waves which can also be called shear waves are the second to arrive at a seismic station because they travel 1.7 times slower than the P waves. They shake the ground in a perpendicular direction to their propagated travel.

The modern seismograph was invented early this century by a Russian seismologist, Prince Boris Golitzyn. This device made possible the modern era of earthquake research. Although earthquakes have occurred and affected mankind for as long as humans have been around, historical records are either lacking or considered unreliable before the middle of the 18th century.

Earthquakes are manifested on the earth’s surface when faults are created; hence, the ground trembles and shakes vigorously. At the surface of the earth, earthquakes are seen and felt by shaking and sometimes shifting the ground in a vigorous way. Earthquakes can also cause tsunamis in cases where the epicenter of a major quake happens offshore. They also play a significant role in triggering landslides and sometimes volcanic activities. The point where an earthquake opens to rupture is known as the focus.

More than a million earthquakes rattle the world each year. But, most are so small that they can only be detected by sensitive instruments called seismogram.

Earthquake is one of the greatest natural disasters. Almost every year around the world earthquakes occur and cause a lot of loses of lives and wealth. Earthquake can’t be prevented and predicted and these are the reasons why it is the most devastating one. Only one way of minimizing its effects is to be careful about its’ reasons and consequences. Throughout this whole composition reasons and consequences of earthquakes are described.