Earthquake
Objective : To introduce earthquake and its effects in life. To adopt the safety measures during earthquake.
Introduction:
Any sudden mild or violent movement of a portion of the earth’s crust due to a natural cause which produces vibration is known as earthquake.
When the earth’s crust vibrates vertically-up and down, it is called vertical quake. When the earth’s crust vibrates horizontally-left and right, it is called horizontal quake.
The point inside the earth’s crust where the first vibration originates is called the focus or hypocenter. The point on the earth surface vertically above the focus from where the vibration spreads is called the epicenter.
The outer layer of the earth is divided into different plates called continental plates. These plates are floating on extremely hot liquid substance called mantle. When they collide or meet one another, there is a kind of motion and sometimes, the rocks bend/break, the plates overlap and create vibration. This may also cause the eruption of volcanoes.
Earthquake is measured by the instrument called Seismograph. It is measured in the unit of Richter scale. Generally, 2 to 5 Richter scale is normal and does not harm much but 6 Richter scale and above is dangerous. In the year 2008 A.D., Northern part of China received an earthquake of 7.8 Richter scale which caused a heavy loss of property and about a lakh of people lost their lives.
There are 2 major earthquake belts in the world. They are:
- Circum Pacific Belt:
This region occupies about 70% of the total earthquake zone in the world. This region includes Chile, Peru, Bolivia, Costa Rica, Mexico, North USA, Canada, Alaska, Kurile Island, Japan, Philippines, New Guinea, New-Zealand etc.
- Mediterranean and Himalayan Belt:
This region occupies about 20 % of the total earthquake zone in the world. This region includes Portugal, Italy, Algeria, Greece, Egypt, Turkey, Iraq, Iran, Afghanistan, Pakistan, North India, Nepal, Myanmar etc.
Remaining 10% of the earthquake zone is occupied by other places. Earthquake causes a great destruction of wealth and the people.
Some of the effects of earthquake are:
- Loss of life and property
- Fire after earthquake
- Earthquake causes tidal waves (Tsunami)
- Earthquake causes epidemic and famine
- Earthquake causes crack on the surface of the earth etc.
People should take great safety measures where earthquake occurs frequently. The governments should be prepared to face the calamities created by earthquake. The students should be taught safety measures. Some of the safety measures every human being should know are given below:
- We should not run and panic during earthquake
- We should secure ourselves under the table or any other safe objects.
- We should come out of the house when the quake is less.
- We should keep household things in such a place which do not fall down during earthquake.
- When we are safe, we should help our neighbors.
- We should inform the governmental and non-governmental organizations for relief.
Presentation for the next day: Group B
- A short presentation on the earthquake, types, belts, effects and safety measures.