Earthquake Causes

Earthquakes are a naturally occurring shock or movement that occurs on or just below the earth crust. This can cause massive devastation in the area of the earthquake and in areas spreading out from the center of the quake.

All true earthquakes are natural and are not linked to any man made activities such as shocks from nuclear testing or landslides that result from extensive building work. There are two main causes of earthquakes - Tectonic activity which is caused by the earth plates moving or faults or volcanic activity which is caused by volcanic eruptions.

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Out of the two earthquake causes tectonic activity is the most common, although volcanic activity can cause earthquakes in certain areas of the world. Tectonic earthquake causes begin when there is movement in the earth Tectonic plates. These plates are made up of sections of the earth crust and they float on the earth mantle. Most of the time these plates are slowly in moving; they might slide towards or away from each other or even slip past each other. However, it is when these Tectonic plates collide or move too closely to each other that an earthquake is caused.

Scientists have devised the Elastic Rebound Theory to describe what happens during these times of movement. To explain this, think about bending a green twig. You will know that you can bend the twig and it will hold up until a certain point, until the energy on the twig becomes too much and it snaps. The point of snapping is known as the Elastic Limit. When this happens the energy created during the bending process is released which makes the twig vibrate.

When Tectonic plates collide or rub against each other the same process occurs and this will cause an earthquake. One example of constantly moving plates is the San Andreas Fault in the US. Here the North American Plate and the Pacific Plate both move in the same direction, but one is faster than the other. This leads to small shocks and occasionally large quakes in the San Francisco area of America.

Volcanic earthquakes are created when a volcano erupts, which can be quite a violent explosion. Usually these earthquakes will affect an area of up to 20 miles around the volcano and the earthquake is not likely to be felt anywhere else in the world.

A volcano is more likely to explode if it contains acidic lava. This is lava that will quickly cool and set when in contact with the air. When this happens the vent of the volcano will become blocked and pressure will build up inside it. Over time this pressure will increase until the volcano erupts. Volcanoes that do not contain acidic lava or which have free flowing lava tend not to erupt in this way and are considered to be much safer.

As you can see there are two main earthquake causes - Tectonic plate activity and volcanic eruptions. Tectonic earthquakes are much more common although there are still instances of volcanic earthquakes in various countries around the globe.

Earthquake Causes

Powerful 8.9 Quake HIts Japan Causes Tsunami 3/11/2011 #prayforJapan

Powerful 8.9 Quake HIts Japan Causes Tsunami 3/11/2011 #prayforJapan Video Clips. Duration : 2.27 Mins.

8.9 Japan earthQuake Causes Tsunami 3/11/2011 Tsunami hits Japan, 8.9 earthquake 8.9 Earthquake hits and rocks Japan You watch as the water brings in cars, debris from building, boats inland over farmland, engulfing all areas as people and animals alike are left helpless. Tsunami watch issued in Hawaii, nothing issued on the west coast yet. Should be only a foot high. 8.9 Quake rocks Japan. 8.9 quake hits japan causes tsunami. Reports were 7.9. A large fire erupted at the Cosmo oil refinery in Ichihara city in Chiba prefecture near Tokyo and was burning out of control. Public broadcaster NHK showed footage of a large ship being swept away by the tsunami and ramming directly into a breakwater in Kesennuma city in Miyagi prefecture. Similar destruction was seen in dozens of communities along the coast.

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What Causes an Earthquake?

Earthquake is one of those natural calamities that can be predictable yet inevitable. We all are customary with the word earthquake and communicate it to the health when the earth starts shaking and vibrating. What is the basic cause of an earthquake? Volcanic activities that are frequent; and the movement of tectonic plates under the crust of the Earth is the presuppose behind the occurrence of earthquakes.

Let us find out more about the types and some more reasons of earthquake.

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The first thing to know is that the Earth's crust is made up of solid core, molten magma mantle and the tectonic plates. All this constitutes the Earth's crust. These plates are intelligent continuously because of the convection currents of the molten lava in the deep layers of the Earth. This results in either the plates sliding against one another, or intelligent away from one another. Well, all such massive movements inside the Earth's crust are felt by the living organisms, together with humans. Mountains and the valleys have been formed due to this continuous movement below the Earth's crust. There is a meeting point which is basically a point of friction in the middle of two plates. This meeting point, in geological terminology, is referred to as earthquake fault line. Sometimes these are also referred to as fractures on the Earth's crust. Once the plates start moving, the potential energy, also referred to as the stored energy, is let loose from the point of intersection, called hypocenter. This results in earthquakes.

Earthquake occurs in three waves. These waves are namely P-waves, the high frequency short distance longitudinal waves; S-waves, the secondary high frequency, short distance transverse wave; and the L-waves, the low frequency, long wavelength transverse waves.

What Causes an Earthquake?

The Causes and Consequences Of Earthquakes

Earthquakes are caused by sudden movement of rock along broken surfaces. Thousands of earthquakes occur in the world every year and a whole of these are not even noticed by most people. Some earthquakes are petite while others are strong and have damaging impact on buildings and the lives of people. Earthquakes are the most unexpected natural disasters and when these happen habitancy do not even get time to save their lives. Many buildings collapse as a ensue of earthquakes and many habitancy get buried under the rubble.

Earthquakes have come to be a fear for many habitancy and to accommodate this many building clubs are building structures which can withstand earthquakes to a sure degree. For this purpose, it is indispensable to seek advice from a geotechnical engineer. Geotechnical engineering experts have vast knowledge of plate tectonics and are able to analyze rocks and soil. Their advice could be helpful in constructing structures which will lessen the ensue of natural disasters like earthquake.

Earthquake & Tsunami In Japan

In a particular year, earthquakes ruin thousands of homes and kill millions of people. They occur plainly on the earth's face due to the movement of plates which are located below the earth's crust. The vibrations arise at the epicenter and that is where the maximum destruction occurs. The vibrations caused by the earthquake have the inherent to cause gigantic destruction and even ruin whole cities.

Earthquakes occur due to two reasons. Firstly, it occurs when a volcano erupts suddenly and secondly due to the movement of plates which can happen due to cracks in the plate or crust waves. Moreover, earthquakes can also arise on the ocean floor and yield ground movements. In the up-to-date years, majority of the earthquakes have occurred at the boundary of the continental plates of North and South America, South Asia and Pacific Ocean. It is believed that stress on the boundary of the plates creates pressure towards the middle and leads to movement of the Earth.

The major consequences of such natural disasters are the loss of human life. The location and magnitude of the earthquake is a major factor which determines the whole of lives that will be lost and the whole of structures that will be damaged. A huge whole of deaths can be caused by collapse of structures which were constructed from heavy and weak materials. Other economic and social consequences comprise trauma, cost of damage, loss of jobs, loss of housing, company interruption, waste of energy and material.

However, clubs and agencies nowadays are implementing strategies as to limit the ensue of such natural disasters to some extent. These planning comprise minimizing the use of land that has already gone through ground damages, shaking, landslides and fault rupture. Their basic aim is to sacrifice the whole of lives that are lost each year due to earthquakes and disasters associated to earthquakes and to sacrifice the damage done to structures and the natural environment. To perform these goals, many countries are building structures which can withstand the devastating effects of earthquakes.

The Causes and Consequences Of Earthquakes

Japanese Earthquake Causes Tsunami (2)

Japanese Earthquake Causes Tsunami (2) Tube. Duration : 14.10 Mins.

Aljazeera capture on 03/11/2011

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