A natural disaster is a major adverse event that causes by nature or the natural processes of the earth. Earthquake is one of them.It measures harshness of a disaster in lives lost, economic loss, and the ability of the population to rebuild. It does not consider events that occur in underpopulated areas disasters. So a flood on an uninhabited island would not consider as a disaster, but it calls a flood in a populated area a natural disaster.
All natural disasters cause the loss. Depending on the harshness, it can lose lives in many disasters. Freezing to death, Falling buildings or trees, being washed away, or heat stroke are just some deadly effects. Some disasters cause more loss of life than others, and population density affects the death count.
An Earthquake is a sudden release of energy accumulated in deformed rocks causing the ground to tremble or shake. When a weak point gives way under the stresses below the surface, huge masses of underground rock shift. Then energy releases as shock waves. These waves move outward from the earthquake’s focus and reach the surface.
It calls the underground point of origin of the earthquake the focus. The point directly above the focus on the surface of the epicenter Earthquakes by themselves rarely kill people or wildlife. It is usually the secondary events they trigger such as building collapse, fires, tsunamis, and volcanoes. The severity of an earthquake on the changed Richter scale. It is a measure of the amount of energy released, which shows by the vibration of an instrument known as the seismometer.
Each unit on the Richter scale represents an amplitude 10 times greater than the next smaller unit. Thus, a value of 5.0 on the Richter scale is 10 times more severe than a value of 4.0 on the Richter scale. Mild earthquakes occur all the time, mostly under the oceans. It often follows the earthquake by aftershocks that gradually fade over several months. Earthquake is a sudden onset hazard and can happen of the year, day or night with sudden impact with no warning. We have conducted extensive research in recent decades but till now, there is no accepted method of earthquake prediction. Most of the predictions of earthquakes that have happened to date have failed. It is therefore only a myth when we say it can predict earthquakes and there is a warning period.
EFFECTS OF EARTHQUAKE
Among the different natural hazards that our planet is subject to earthquakes the most feared because of their sudden impact and the devastation, they cause in just a few seconds. The Himalayan mountain ranges and the Indian Peninsular regions are most vulnerable to earthquake shocks. However, no location could describe as ‘not susceptible’ to earthquake occurrence.
MITIGATION STRATEGIES OF EARTHQUAKES
To reduce the impact of earthquakes, which is a regular phenomenon in countries like Japan and Indonesia, various mitigation (mitigation is any action taken to minimize the extent of a disaster) strategies have taken up by the governments and the people of these countries to minimize the impact of these hazards. Following are the few mitigation measures for earthquakes :
A. Structural Mitigation: Engineered structures should design and built to withstand ground shaking. Architectural and engineering inputs need to put together to improve building design and construction practice. We must also analyze soil type before construction and we must not build structures on soft soil. Buildings built on soft soils are more likely to get damaged even if the earthquake is not strong in magnitude. The similar problem persists in the alluvial plains and on the river banks. It sustains heavy damages when the ground is soft.
B. Non-structural Mitigation Measures: The Bureau of Indian Standards has published building codes and guidelines for safe construction to reduce the impact of earthquakes. Before it constructs the buildings, the building plan has to check by the municipality to verify. If the structure conforms to the building guidelines set by the Government. Many existing lifeline buildings like hospitals, offices, schools, fire stations need to retrofit. With safety devices based on these guidelines as they play a very crucial role in case a disaster strikes.
It must arrange sensitization and training programs for the public like them aware of such hazards. Also, damages from secondary are like fire, floods, landslides, etc. should reduce by identifying potential landslide sites and restricting construction in those areas.