Sichuan Province Earthquake

On May the 12th 2008 at 2:28pm local time, a 7.9 magnitude earthquake hit the Sichuan Province in China. It killed seventy thousand people and left eighteen thousand people missing. The earthquake affected an area where fifteen million people lived.

These maps show where the epicentre of the earthquake was.

The quake majorly affected two cities in China. They are Wenchuan in which the Sichuan province is located and Chengdu, where four million people were killed and around one million buildings destroyed.

The coordinates in which the earthquake was located are: (Latitude 31°, Longitude 103.4°). The geological location is which plate the earthquake happened on. In this case the earthquake happened between the Eurasian and the Indian plate boundaries.

The earthquake the occurred in the Sichuan province, known as the Sichuan Province Earthquake or the Wenchuan Earthquake happened nineteen kilometres below the surface. The duration of the earthquake lasted two minutes. There were one hundred and forty-nine to two hundred and eighty four major aftershocks, with a total of forty-two thousand seven hundred and nineteen aftershocks.

Many of destructive earthquakes have occurred in China’s Central Region, ranging in magnitude from 7 to 7.9, along the same seismic belt where the May 12, 2008 earthquake struck. This is shown in the image below.

The earthquake originated on the Longmenshan fault, a north eastern fault. The fault was a result of the crust from the Tibetan Plateau going under the crust underlying the Sichuan Basin.

The instrument used to record seismic waves (which are the waves moving through the earth during an earthquake) is called a seismometer. The graph in which the seismometer draws is called a seismograph. A seismometer must be able to move with the vibrations caused by the seismic waves, but still be stationary on the ground. This is achieved by having a movable pen attached to a recording table. This is shown in the diagram below.

There are three types of seismic waves P, S and L waves. P waves also known as primary waves are high frequency with a short wave length. S waves also known as secondary waves are the same as P waves except slower and arrive after P waves. Finally L waves also known as surface waves are low frequency with long wave lengths. They are responsible for the majority of the damage caused by earthquakes.

Earthquakes are triggered when tectonic plates are under pressure and forced to move. The tectonic plate theory states that the Earth’s crust is made up of several plates, which float on the Mantle. These plates are free and move around slowly, they either drift towards each other, away from each other or slide past each other. Most of the earthquakes which are felt by people are located at the edges of two plates where the plates collide or try to slide past each other.

There is an almost certain likelihood that a similar earthquake may occur in the future as there have been similar ones in the past. Earthquakes have never been certainly predicted; however in recent years scientists have been able to predict some of the more recent. Is saying this, the Sichuan Province earthquake was certainly not predicted, and that is one of the reasons it was so disastrous.

The Chinese have built better and more earthquake resistant buildings, to provide some more support in case of another devastating earthquake. Nearby countries that suffer from frequent earthquake build homes out of lighter materials so that they will nit trap as many people. Although no modern day building would be completely safe is a big enough earthquake hit.

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