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World Geography MCQs – 08 (Plate Tectonics and Earthquakes)

Plate Tectonics and Earthquakes MCQs with answers and explanations for all examinations.

1. The continental drift was given by which among the following ?

(a) Alfred Wegener
(b) Charles Darwin
(c) Inge Lehmann
(d) None of the above

Correct Answer – (a) Alfred Wegener

  • The theory of continental drift was propounded by Alfred Wegener in 1912.
  • He was a German geologist.
  • Inge Lehmann was a Danish seismologist who discovered the core of the Earth and was a leading authority on the theory of existence of the upper mantle.

2. As per the continental drift theory, ‘Pangaea’ was ?

(a) A Supercontinent
(b) An Active volcano
(c) A Superocean
(d) None of the above

Correct Answer – (a) A Supercontinent

  • As per the continental drift theory of Alfred Wegener, present continents were once joined in a supercontinent called ‘Pangaea’.
  • He also proposed that the Pangaea later separated into the Gondwanaland and Angaraland and the space between them was filled with water that was called Tethys Sea.
  • Later the Gondwanaland separated into different parts to form the Indian subcontinent (peninsula) , Madagaskar, Australia and Antarctica.
  • Similarly Angaraland separated into different parts to form the North America South and Africa.

3. Consider the following statements about Plate Tectonics ?

1. Lithosphere is made up of many large and several smaller sections called tectonic plates.
2. When tectonic plates move or collide, it causes Earthquakes.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (d) All of the above

  • Earth’s lithosphere is made up of many large and several smaller sections called tectonic plates.
  • There are six major lithospheric plates : 
    • Pacific plate
    • American plate
    • Eurasian plate,
    • African plate
    • Austral-Indian plate
    • Antarctic plate.
  • Earthquakes and volcanoes are caused when plates separate, collide, or slide past one another.

4. Consider the following statements about Plate boundaries :

1. In Convergent Plate Boundaries, plates move away from each other
2. In Transform Plate Boundaries, plates slide past one another

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (b) 2 only

  • Tectonics Plates while floating on liquid asthenosphere interact with each other and form different types of boundaries.
  • There are three types of plate boundaries:
    • Convergent Boundaries → Where plates move toward each other
    • Divergent Boundaries → Where plates move away from each other
    • Transform Boundaries → Where plates slide past one another

5. Consider the following statements :

1. When an oceanic plate collides with a continental plate, the continental plate is always subducted.
2. When two oceanic plates collide, the denser of the two plates is subducted.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (b) 2 only

  • When an oceanic plate collides with a continental plate, the oceanic plate is always subducted as the oceanic plate is denser than the continental plate.
  • This leads to the formation of a volcano or a volcanic island in the sea.
  • When two oceanic plates collide, the denser of the two plates is subducted. This leads to the formation of chains of volcanoes called continental volcanic arcs.

6. Consider the following statements :

1. When two continental plates collide, folded mountains are formed.
2. Collision of two continental plates is responsible for formation of the Himalayas.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (d) All of the above

  • Both the statements are correct.
  • When two continental plates collide, the crust at both the sides is too light and buoyant to be subducted, hence neither plate is subducted in the continental-continent collision.
  • In this case, folded mountains are formed.
  •  Collision of two continental plates is responsible for formation of the Himalayas.

7. The Red Sea and the Gulf of Aden are formed due to which among the following ?

(a) Continental-Continental Divergence
(b) Continental-Continental Convergence
(c) Continental-Oceanic Divergence
(d) Oceanic-Oceanic Divergence

Correct Answer – (a) Continental-Continental Divergence

  • The divergent plate boundaries on the continents lead to the formation of Continental Rift Zones.
  • When Continental Rift Zones are formed, the earth is stretched and a rift is created. 
  • When such a rift gets filled with water, it leads to the development of water bodies like the Red Sea and the Gulf of Aden.

8. Consider the following statements about Transform Plate Boundaries :

1. These are the places where two plates slide past each other.
2. Earthquakes are most common but Volcanoes rarely develop at transform plate boundaries.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (d) All of the above

  • Transform Plate Boundaries are the places where two plates slide past each other.
  • No subduction occurs at such boundaries.
  • Earthquakes are most common but Volcanoes rarely develop at these boundaries.

9. Which of the following statements is/are true ?

1. During the earthquake, the place in the earth’s crust where the movement starts is called the epicenter.
2. Greatest damage is usually caused closest to the epicenter.

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer – (b) 2 only 

  • When the Lithospheric plates (also known as tectonic plates) move, the surface of the earth vibrates. 
  • The vibrations can travel all around the earth in the form of P-waves and S-waves. 
  • These vibrations are called earthquakes. 
  • The place in the crust where the movement starts is called the focus. 
  • The place on the surface directly above the focus is called the epicenter. 
  • Vibrations travel outwards from the epicenter as waves. 
  • Greatest damage is usually caused closest to the epicenter and the strength of the earthquake decreases away from the center.

10. Consider the following statements :

1. The point where earthquakes are generated is called focus.
2. Focus is below the surface of the earth.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (d) All of the above

  • Both the statements are correct.
  • The point where earthquakes are generated is called focus or hypocenter.
  • Epicenter is the point on the Earth’s surface that is directly above the focus.
  • It is the place on the earth’s surface where earthquake waves reach first.

11. The magnitude of the earthquake is measured in which among the following ?

(a) Richter
(b) Pascal
(c) Parsec
(d) None of the above

Correct Answer – (a) Richter

  • The magnitude of the earthquake is measured on the Richter scale.
  • It is to be noted that the Richter scale has no upper limit theoretically, however, the earthquakes of magnitude 10 or larger cannot happen. 
  • The strongest earthquake ever recorded was a magnitude 9.5 which occurred in 1960 near Valdivia, Chile.
  • Pascal is used to measure pressure.
  • Parsec is a unit of length used to measure the distance between the astronomical objects outside of our solar system.It is the  largest practical unit of length. One parsec is equal to 3.26 light years.

12. The lines on a map that connect points of equal intensity earthquakes are called ?

(a) Iso-seismals
(b) Isobars
(c) Isotherms
(d) None of the above

Correct Answer – (a) Iso-seismals 

  • Isoseismals are the lines on a map that connect points of equal intensity earthquakes.
  • Isobars are the lines on a map that connect points of equal atmospheric pressure at a given time.
  • Isotherms are the lines on a map that connect points of equal temperature at a given time.

13. Consider the following statements about Seismic Waves :

1. They are divided into two major categories called Body Waves and Surface Waves.
2. Surface Waves are further divided into P-waves and S-waves.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (a) 1 only

  • Seismic Waves are divided into two major categories called Body Waves and Surface Waves.
  • Body Waves:
    • Originate at focus and travel through the Earth’s interior and arrive before surface waves. 
    • They are further divided into P-waves and S-waves.
  • Surface Waves:
    • They move along the surface of the earth. 
    • Their speed is slower than body waves.
    • It is to be noted that shallow earthquakes(where focus is near the surface) produce stronger surface waves whereas deeper earthquakes (where focus is deep in the earth’s interior) produce weaker surface waves.

14. Consider the following statements about Seismic Waves :

1. The Primary waves or P-waves vibrate parallel to the direction of wave movement.
2. Secondary waves vibrate perpendicular to the direction of wave movement.

(a) 1 only
(b) 2 only
(c) None of the Above
(d) All of the above

Correct Answer – (d) All of the above

  • The Primary waves or P-waves are the longitudinal waves which vibrate parallel to the direction of wave movement.
  • They can travel through solid, liquid or gas however their speed is fastest in denser solid materials.
  • Secondary waves or S-waves also known as transverse waves vibrate perpendicular to the direction of wave movement.
  • They can only travel through solids.

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