article on earthquake
Answers
Answer:
An earthquake is the shaking of the surface of the Earth. Earthquakes can be extremely violent. They are caused by weird movements of the Earth's tectonic plates.
The study of earthquakes is called seismology.[1] Earthquakes are usually quite brief, but may repeat. The sudden release of tension in the tectonic plates sends waves of energy that travel through the Earth. Seismology studies the cause, frequency, type and size of earthquakes.
Earthquake clusters
Most earthquakes form part of a sequence, related to each other in terms of location and time.[2] Most earthquake clusters consist of small tremors which cause little to no damage, but there is a theory that earthquakes can recur in a regular pattern.[3]
A foreshock is an earthquake that occurs before a larger earthquake, called the mainshock.
An aftershock is an earthquake that occurs after a previous earthquake, the mainshock. An aftershock is in the same region of the main shock but always of a smaller magnitude. Aftershocks are formed as the crust adjusts to the effects of the main shock.[2]
Earthquake swarms are sequences of earthquakes striking in a specific area within a short period of time. They are different from earthquakes followed by a series of aftershocks by the fact that no single earthquake in the sequence is obviously the main shock, therefore none have notably higher magnitudes than the other. An example of an earthquake swarm is the 2004 activity at Yellowstone National Park.[4]
Sometimes a series of earthquakes occur in a sort of earthquake storm, where the earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, and with some of the later earthquakes as damaging as the early ones. Such a pattern occurred in the North Anatolian fault in Turkey in the 20th century.[5][6]
Tsunami
Main article: Tsunami
File:20110311Houshu.ogv
Animation of the 2011 Sendai tsunami.
Tsunami or a chain of fast moving waves in the ocean caused by powerful earthquakes is a very serious challenge for people's safety and for earthquake engineering. Those waves can inundate coastal areas, destroy houses and even swipe away whole towns.[7] This is a danger for the whole mankind.
Unfortunately, tsunamis can not be prevented. However, there are warning systems[8] which may warn the population before the big waves reach the land to let them enough time to rush to safety.
Earthquake-proofing
Main article: Earthquake engineering
Earthquake-proof buildings are constructed to withstand the destructive force of an earthquake. This depends upon its type of construction, shape, mass distribution, and rigidity. Different combinations are used. Square, rectangular, and shell-shaped buildings can withstand earthquakes better than skyscrapers. To reduce stress, a building's ground floor can be supported by extremely rigid, hollow columns, while the rest of the building is supported by flexible columns inside the hollow columns. Another method is to use rollers or rubber pads to separate the base columns from the ground, allowing the columns to shake parallel to each other during an earthquake.
To help prevent a roof from collapsing, builders make the roof out of light-weight materials. Outdoor walls are made with stronger and more reinforced materials
Explanation:
the sudden shaking of the earth caused by internal forces of the earth is called the earthquake it organelles from the interior of the earth and the point of origin is called the focus the point on the surface of the earth exactly above the focus is called the epicenter the earthquakes and shock waves all around and cause widespread destruction to life and property the vibrations of an earthquake spread out as concentric waves from the focus these vibrations are called seismic waves the intensity of the earthquake is maximum near its epicenter the surface of the earth can shake due to movement of the lithospheric plates volcanic eruptions or even bomb explosions there r 3 types of earthquake waves primary waves secondary waves surface waves sismograph is the instrument which record the intensity of the earthquake waves . according to an estimate 1million earthquake are recorded every year .