Earthquakes


 
 
Concept Explanation
 

Earthquakes

Earthquakes: An earthquake is a sudden movement or a fracture in crust and the upper layer of the mantle.

The internal structure of the Earth:

Crust: Crust is the thin outer covering of the earth.The crust is thinner at the ocean floor(about 6-11 km) than under the continents (about 30-70 km).

Outer core: Outer core is about 2300 km thick. It is believed to contain iron and nickel in a molten state. There is also some sulphur present here.

Mantle: Mantle is the layer immediately beneath the crust. It is about 2900 km thick and consists of semisolid rock, iron, magnesium, and calcium.

Inner core: Inner core is about 1200 km thick. It is believed to be composed alomost entirely of solid iron.

                                  

 

The branch of science concerned with earthquakes and related phenomena is called seismology.

   Plate Tectonics: Earth’s lithosphere is not one continuous piece, but is broken into many pieces called plates. The earth is divided into seven large plates and several smaller plates. These plates move with respect to one another by about a few inches every year.  The theory that the surface of the earth is made of plates that move with respect to one another is called plate tectonics.

Sample Questions
(More Questions for each concept available in Login)
Question : 1

The weak zones around boundaries of plates underneath the Earth, which are prone to slide and cause earthquake are commonly known as _________________

Right Option : A
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Question : 2

Each fragment of Earth's crust is called a ____________ .

Right Option : A
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Question : 3

Movement of the tectonic plates leads to ________________

Right Option : B
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