What is an Earthquake?
Earthquake occurs when two blocks of Earth suddenly slip over each other. The surface where slips occurs is called fault or fault plane. The location at which earthquake starts below the earth surface is called as Focus, and the location exactly above it of earth’s surface is called as Epicenter.
 |
| source: worldatlas.com |
Why and where it occurs?
The earth is divided into three major layers they are as follows:
Crust :- Thickness of this layer ranges from 5 to 70 km. It is 1% of the whole earth.
Mantle :- The thickness of Mantle is 2900 km. It is 84% volume of earth.
Core :- It is 15% volume of earth. It is further divided into two parts as follows:
a) Outer Core
b) Inner Core
The crust and upper layer of mantle is divided into tectonics plate, and the edge of plate is called as plate boundaries. The plate boundaries consists of faults and most of the time earthquake occurs on these faults. The edges of plates are rough so they stick to each other. Even edges are stuck, the remaining part of plate keeps moving. When the plate has reached far enough at that time edges cannot hold each other and they unstick and move. Due to this Earthquake occurs.
Types of Earthquake Waves
Earthquake wave are of majorly three types. They are as follows:
P wave or Longitudinal waves :- It is similar to sound wave. It can travel through solid, liquid and gases state.
S wave or Transverse wave :- It can travel only through solid.
L wave or Surface wave :- When body wave i.e. P and S wave, when interacts with surface of earth it is called Surface wave.
Effects of Earthquake
Earthquake has many effects and it can also lead to another diaster which can be caused due to earthquake as root cause
On ground :- Fissures settlements, Landslides, Liquefication, earth pressure and many more.
On manmade structures :- Cracking, Collapse of building, Buckling and many more.
On water :- Tsunami, Waves Hydro-Dynamic Pressure, etc.
Measurement of Earthquake
Siesmograph is used to measure earthquake.
Richter scale :- It is used to measure magnitude of earthquake and it ranges from 0-10.
Mercalli scale :- It is used to measure intensity of earthquake and it ranges from 1-12.
Why earthquake is a matter of concern to world?
Earthquakes occur suddenly at a place and it spreads to nearby places so very less time is provided to people to respond to it. The damage depends on severity of earthquake. It causes much damage to environment. Many lives of human, animals, birds and other living beings of an area are lost where earthquake occured with severity and less damage occurs where it occured with less severity. There are much loss causedfinancially to a country such as building collapse, cracks or hole in roads. The place where earthquake occurs resident people have to deal with so much of physical and mental pain and pressure. So earthquake is one of the dangerous natural disaster.
0 Comments