Get A+ with YaClass!
Register now to understand any school subject with ease and get great results on your exams!

### Theory:

Seismograph:
An instrument is used to detect and record earthquakes is called a seismograph. It consists of a metal rod attached to a fixed base. During an earthquake, the base moves, but the rod does not move. The movement of the base to the rod is commonly transformed into an electrical voltage. The electrical voltage is recorded on magnetic tape, paper, or any other medium. This record is proportional to the motion of the metal rod relative to the earth, but one can convert it to a record of the absolute motion of the ground.

Seismograph

Seismic or fault zones of India:
In India, the most threatened areas are as follows
• Kashmir
• Western and Central Himalayas
• Rann of Kutch
• The whole of North-East
• Rajasthan and the Indo-Gangetic Plain
• Some areas of South India
The power of an earthquake is measured in terms of a magnitude on a scale, known as the Richter Scale. Destructive earthquakes have magnitudes higher than $$7$$ on the Richter Scale. Bhuj and Kashmir earthquakes had magnitudes greater than $$7.5$$.

Protection against earthquake:
One can predict the earthquakes. So, the buildings in fault zones or seismic zones should be designed to withstand major tremors. It is preferable to make the structure simple so that it is ‘Quake Safe’.
• It is better to use mud or timber than using heavy construction material in a highly seismic zone. Keep roofs as light as possible because if the structure falls, the damage will not be heavy.
• While designing the interiors, we should ensure that cupboards are fixed to the wall so that they don't fall easily. Likewise, hang photo frames, clocks and other design articles on the wall so that they don't fall on people during the quake.
• It is necessary to install fire fighting equipment in all buildings, especially in tall buildings, because there is a chance of fire during the quake.
Take the following steps to protect yourselves in the event of the earthquake:
Inside the home:

Hide under a table till the earthquake stops.
• Do not stand or sit near heavy objects.
• Protect your head with a pillow if you are in a bed.
Hide under a table

Outside the home:
• Stay away from buildings, trees, and overhead power lines.
• If you are in a bus or a car, do not come out till the tremors stop. Ask the driver to drive to a safe place.