An earthquake is a trembling or a shaking movement of the Earth's surface. The dictionary meaning of the word earthquake is “shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity”. The word earthquake is also widely used to indicate the source region itself. The solid earth is in slow but constant motion and earthquakes occur where the resulting stress exceeds the capacity of Earth materials to support it.
Earthquakes produce various damaging effects to the areas they act upon. This includes damage to buildings and in worst cases the loss of human life. The effects of the rumbling produced by earthquakes usually leads to the destruction of structures such as buildings, bridges, and dams. They can also trigger landslides. Earthquakes have varied effects, including changes in geologic features, damage to man-made structures, and impact on human and animal life.
Earthquakes often cause dramatic and geomorphological changes, including ground movements either vertical or horizontal along geologic fault traces, rising, dropping, and tilting of the ground surface, changes in the flow of groundwater.
Besides producing floods and destroying buildings, earthquakes that take place under the ocean can sometimes cause tsunamis, or tidal waves. Tsunamis are high and long walls of water which travel at a very rapid rate. They are notorious for destroying entire populations and cities near coastlines. In 1896 Sanriku, Japan, with a population of 20,000, suffered such a fate. Several thousand stations monitor earthquakes all over the world. Each station contains an instrument, called a seismograph, used to detect arrival times and record seismic waves.
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 play a major role into understanding the composition and materials that exist within the Earth (Merali and Skinner, 2009, p.252). Earthquakes are the main source of insight into the inner workings of the earth, due to the nature of the seismic waves they produce. P and S waves are reflected and refracted at different boundaries within the earth, and this enables seismologists to make inferences about the internal composition and structural of planet Earth. (Merali and Skinner, 2009, p.252).
The earth is split into four layers, inner and outer core, the mantle and crust. The top of the mantle and crust make up what is like the skin of our earth (see source 2). The skin is split up like a puzzle and we call these puzzle pieces’ tectonic plates (see source 1). These plates are constantly moving and the plate boundaries (edges of the plates) move and slide past one another. Sometimes as the plates move the plate boundaries become stuck. Pressure builds up in the stuck area over time and eventually breaks. This is why earthquakes occur due to the sudden movement of the plate sliding and breaking creating a fault line to go off. The fault line is the line on which the
Tsunamis can go the same speed as a jetliner and that massive wave can out run the fastest runner. When there is a lot of waves at once, or the water goes back that is a sign that a tsunami is coming. If that tsunami is far then people need to get to the tallest and strongest building there is in the city that way they are safe and helicopter can pick them up. Tsunamis can wipe out an entire city or 1/4 of the country. Tsunamis can last up to an hour, or more.
Earthquakes are caused by tectonic plates moving in the earth's crust. They either move apart or pull together at faults. Two forms of faults are normal faulting where the hanging wall moves downward causing rocks to be pulled apart by tension and reverse faulting, which is the opposite where the hanging wall moves upward casuing rocks to be forced together by tension. These movements cause tectonic plate boundaries called divergent boundaries, convergent boundaries and transform boundaries. Each boundary is different and play a
TOHOKU, Japan, Friday, Mar. 11 -Yesterday, a 9.0 magnitude Earthquake struck the east of Tohoku, Japan. The epicentre of the earthquake was located approximately 72 km east of Tohoku (38.3 degrees North latitude and 142.4 degrees East longitude), or 130 km east of Sendai as shown by the X in figure 3 below. The focus of the earthquake was 24.4 km under the epicentre. The earthquake therefore caused a tsunami due to the displacing of water above the Pacific Plate. The earthquake and tsunami together have caused approximately 20,000 deaths, 6152 injuries and 2500 people missing. Approximately 90% of these deaths were by drowning. Approximately 140,000 people have been displaced and over 500,000 buildings and structures have been destroyed or damaged. The early warning system of Japan stopped many bullet trains, and many residents received texted warnings of the earthquake and tsunami on their mobile phones giving them time to evacuate. Figures 1 and 2 show exactly how destructive the tsunami caused by the Tohoku Earthquake was.
Out of all the natural disasters that we talk about in class, the most deadly would have to be a Tsunami. Compared to earthquakes, Tsunamis have cause more deaths since 1945. A Tsunami is likely to strike anywhere on the west coast, including Santa Cruz in California – United States – North America – 36:58:24N 122:02:09W. A Tsunami is a giant “wave” of water that is caused by a sudden shift in the sea floor. The wave is a result of the water attempting to regain its equilibrium, which is driven by gravity. The size of the wave is determined by how much the sea floor is moved vertically, and how quickly it shifts. A greater water depth helps as well. They can travel up to five hundred miles an hour and have wave heights of one hundred feet. Earthquakes are the leading cause of Tsunamis. People who live in California are well aware of earthquakes that are frequently caused by the San Andreas Fault. However, not many are aware of the results of earthquakes that occur out in the Pacific Ocean. Tsunamis have also been referred to in the past as seismic sea waves, but Earthquakes aren’t the only cause of this phenomenon. Landslides, nuclear explosions, volcanic eruptions, and extra terrestrial impacts also have great water displacement results.
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.
Tsunamis caused by the Earthquake leads to flooding along the coastal environment. This damages any homes. Flooding caused new lakes or sag ponds on the land. Increasing groundwater flow from springs and displacing stream channel. ("Flood Consequences")
What have they learned since the quake quite allot. The fault moved in a fashion that geologists of
An earthquake occurs abruptly and causes severs damage to people, property, landscape and more. A great mega-thrust earthquake, known as the Great Tohoku Earthquake has shaken Japan at 5:46:24 UTC on March 11, 2011. It caused a severe disaster, including tsunami and nuclear radiation exposure.. This mega-quake located at the latitude 38.297 degree North and longitude of 142.372 degree East, near the east coast of Honshu, Japan (USGS, 2013). An earthquake and tsunami waves caused widespread damage to many areas of Japan. People in Japan are still recovering from the damages.
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.
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).