We all know what an earthquake is. When the surface of the earth trembles, we call it an earthquake. Sometimes it trembles mildly, but sometimes the shaking is very violent.
The inside of the earth is a very hot burning mass of liquid matter. Due to some causes this heated matter in some part cools. It contracts. Its result is that the upper part of the earth at that particular place is drawn down. Then this produces cracks on the surface of the earth. The water of the ocean flows down through these cracks and comes in touch with the hot liquid. Sometimes the rain-water also finds its way down. It comes in contact with the heated matter. Steam is thus produced and it wants to rush out and the earth is violently shaken. Thus the earthquake is caused. There is an instrument called seismograph. It can show the force, place etc. of an earthquake. The point at which a earthquake breaks out is called the epicenter of the earthquake.
If the earthquake is mild, it does not do much harm. But if it is violent, its effect is dangerous. It causes a great loss of life and property. If the earth trembles for two or three minutes violently, many brick-built houses fall down and the inmates are buried alive. It is difficult for men to remain standing. If they cannot run away to an open place they may be killed by the falling of houses. Due to severe shocks, trees are uprooted and the earth of one place may go down and that place may be filled with water from below. Sometimes the water of ponds and rivers swells all on a sudden and sometimes the water of a river or a part of the ocean is dried up, and land appears there. Thousands of lives are lost. Many people become wounded. Many people may save their lives, but their properties are lost. Thus they become poor. Crops are destroyed. As a result a famine may break out. People from other parts of the country should help these people with sufficient money to make good their losses.
Some notable earthquakes
There was a violent earthquake in India in 1897. A terrible earthquake visited Japan in the year 1926. It caused great loss to that country. Even the Indians helped Japan at that time. In 1934, there was a great earthquake in North India. The quake was felt in Bengal also, but its effect in North Bihar and Nepal was terrible. Several town of Bihar suffered great damages as a result of this earthquake. Many people lost their lives. Many were rendered homeless. The Indians as well as the Englishmen helped the people of Bihar. In 1951, there was a terrible earthquake in upper Assam. It caused a great loss. Every year we read in newspapers reports of great earthquakes in different parts of the world. Recently, in 1989 a violent earthquake occurred in Armenia in Soviet Russia. This earthquake caused great damage to properties and loss of many lives. Many countries of the world sent help for the redress of the suffering people.
The earthquake is a terrible enemy of mankind. Men cannot control it. They do not know when it will take place. They cannot prevent its occurrence. So they have only to depend upon God to save themselves from this great calamity. Wooden houses should be built where earthquakes occur very often.