


Release of energy waves called seismic waves in the crust of earth, leads to the creation of a natural disaster called earthquake. Earthquakes can be recorded using an instrument called as seismometer. Richter scale is used to represent magnitude and intensity of earthquakes. Those earthquakes which show reading of 3 on Richter scale are usually not harmful as such, but earthquakes which show reading of 7 or more are extremely harmful. So, more the scale of reading more harmful is the earthquake.
earthquakeThe origin point of seismic waves is called epicenter of earthquake. If epicenter is located near the sea then it can cause the creation of Tsunami waves. Earthquakes lead to severe shaking of earth’s surface, landslides etc. Earthquakes are generally results of natural phenomena like geological stress, volcanic eruptions, landslides etc but earthquakes can also be induced by some human activities like mine blasts and nuclear experimentation etc. the first rupture point of earthquake is called focus hypocenter and epicenter is the point at ground level exactly above the hypocenter.
Naturally occurring earthquakes and earthquake storms
Those earthquakes which occur due to some natural phenomena are generally more intensified and harmful. These Tectonic earthquakes can occur just anywhere in earth where enough elastic strain energy is stored to conduct fracture propagation at a fault plane. There are basically 3 types of faults, which cause creation of the earthquakes- reverse, strike-slip and normal. Reason of a certain displacement decides the intensity of the earthquakes. Earthquakes are classified as extreme destruction source of nature because an exact warning can’t be extracted about earthquakes. Even sometimes earthquakes can hit a region in a series. In this situation one new earthquake gets triggered due to displacement, shaking or stress induction by previous strike of earthquake. This situation is called earthquake storm. This is extremely detrimental for human life and property.
Impacts of earthquakes
Impacts of earthquakes can be classified into various classes-
ground-ruptureGround rupture- It is the main result of an earthquake strike. Shaking of ground causes severe damage to the buildings or other structures on the ground including houses etc. Shaking of ground at a particular place depends upon the distance of that place from the epicenter. Severe shaking of ground causes destruction of all the buildings of a city and many people die by burring into the building materials.
It can’t be avoided because earthquakes strike a place all of a sudden. So this shaking of ground compels construction engineering to develop buildings which are resistive to the strikes of earthquakes. The branch of engineering deals which deals with anti-earthquake construction is called Earthquake construction.
Landslides- Earthquakes causes instability of land results into landslides; this claims many lives at the effected zone.
Fire- Earthquake causes breaking of electrical power lines or gas supply lines which causes incidents of fires. Water lines also got ruptured and decreased pressure makes it impossible to control the spread of fire. In earthquake of San Francisco in 1906, more deaths happened because of fire as compared to earthquake itself.
Soil liquefaction- When severe shaking occur then soil or sand loses their strength for a temporary period and gets converted from solid to liquid. This liquefaction causes sinking of buildings, bridges etc.
Tsunami and floods- when epicenter of an earthquake is located near sea, then the traveling of seismic waves below the sea causes generation of Tsunami waves, which can ravel at a speed of 600-800 kilometers per hour. For creation of Tsunami earthquakes are needed to be highly intensified. In general earthquakes having reading of less then 7.5 on the Richter scale are not able to generate Tsunami waves. But stronger earthquakes can are comfortable enough to create Tsunamis. Sometimes when earthquake triggered landslides fall into sea, it leads to the creation of Tsunami waves.
Earthquake Construction
earthquake-constructionIt is defined as the branch of the modern architectural engineering, having major concern of making structures which can withstand a severe earthquake shock. This branch of engineering is earning major concerns by countries like Japan, Chine, Turkey, Algeria and other countries near boundaries of tectonic plates. Because these areas of world are much more susceptible to strikes of earthquakes and major steps are necessary to avoid the destruction of human life and infrastructure.



