Geography · General Awareness

Geology and Earth Structure

1,268 Questions

Geology and Earth Structure explores the physical composition of the planet, including its layers, tectonic plates, and seismic activity. This topic is a core component of geography and general science sections in various competitive exams. Reviewing these concepts builds a solid foundation for answering questions related to natural phenomena.

Layers of the EarthTectonic PlatesEarthquakes and VolcanoesGeomagnetism ApplicationsGeophysical MethodsLandform Formation

Geology and Earth Structure Questions

Multiple choice

Which of the following is not correct?

  1. The inner most layer of the earth is called crust.

  2. The core of the earth is extremely hot.

  3. Hot lava coming from the Earth's core proves that the earth is very hot.

  4. The mantle is a layer beneath the crust.

  5. The Earth's interior is composed of four layers.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

No, the inner most layer of the earth is called inner core. The Earth's inner core is made up of iron and nickel. It has trapped gases and hot liquids under great pressure. Sometimes these gases burst out and explode outside the crust as volcanoes.

Multiple choice

Directions: Read the passage given below and answer the question that follows.

Earthquakes happen all the time. In fact, nine thousand earthquakes occur around the world everyday. Most of them are so small that we do not even notice them. But at 5:46 a.m. on the morning of 17th January, 1995, Japan was struck by its biggest earthquake in 72 years. It happened about 20 km. below the earth’s surface.

Up to nine thousand earthquakes happen everyday in the world but they are not noticed because they are ___________.

  1. very deep

  2. ineffective

  3. very small

  4. under the sea
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is mentioned in the 2nd line.

Multiple choice

Which of the following statements about minor plates is correct?

  1. Cocos plate lies between Asiatic and Pacific plates.

  2. Caroline plate lies between Central America and Pacific plates.

  3. Philippine plate lies between Philippine and Indian plates.

  4. Fuji plate lies southwest of Australia.

  5. Nazca plate lies between South America and Pacific plates.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Caroline plate is located between Philippine and Indian plates (North of New Guinea). Nazca plate lies between South America and Pacific plates.

Multiple choice

Which one of the following is not a major plate?

  1. India-Australia-New Zealand plate

  2. Arabian plate

  3. Antarctica plate

  4. South American

  5. Africa with the eastern Atlantic floor plate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Minor plates are:  1) Cocos plate : Between Central America and Pacific plate. (ii) Nazca plate : Between South America and Pacific plate. (iii) Arabian plate : Mostly the Saudi Arabian landmass. (iv) Philippine plate : Between the Asiatic and Pacific plate.

Multiple choice

Seismic waves that vibrate perpendicular to the direction of their path

  1. travel only through the solid part of the earth

  2. travel only through the liquid part of the earth

  3. travel through both solid and liquid parts of the earth

  4. Density of a material does not affect their propagation.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

S-wave, secondary wave or shear wave (sometimes called an elastic S-wave) is one of the two main types of elastic body waves. S-wave moves as a shear or transverse wave, so motion is perpendicular to the direction of wave propagation. S-waves are like waves in a rope. Unlike P-wave, S-wave cannot travel through the molten outer core of the earth and this causes a shadow zone for S-waves opposite to where they originate.

Multiple choice

Which of the following factors help(s) in the study of the earth’s interior?

  1. Density of the earth
  2. Seismic properties
  3. Analogy from outer space

  1. Only 2

  2. Only 1 and 2

  3. 1, 2 and 3

  4. Only 2 and 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Knowledge of the earth's interior is based on the reactions of seismic waves from earthquakes; the density and state of materials that these seismic waves encounter. Some of this understanding is based on our current understanding of how the earth formed - mainly, how our planet cooled down and formed; how the heavier materials such as metals sunk to the center, etc. Rock that is torn off and expelled by volcanism is studied as another indicator of what lies below the surface. Another clue lies in meteorites that have landed on earth. The study of earth's magnetic field and gravitational properties also indicate or strongly infer what lies deep in earth's interior. 

Multiple choice

Which of the following statements is/are not correct?

  1. P - waves are the last waves to reach the earth's surface from the interior of the earth.
  2. L - waves are continued to the surface of the earth.
  3. S - waves are transverse in nature, similar to light waves.
  4. P - waves cannot transmit through liquids, which lack rigidity.

  1. Only 1 and 4

  2. Only 4

  3. Only 3 and 4

  4. Only 2, 3 and 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

P - waves are the first waves to reach the earth's surface from the interior of the earth. L - waves are one of the types of surface waves. S - waves are transverse in nature, similar to light waves. P - waves can transmit both through solids and liquids.

Multiple choice

Match the following:

List - I List - II
1. Lithosphere A. The lower part of mantle
2. Asthenosphere B. Whole of core
3. Mesosphere C. Slow speed of seismic waves in this zone
4. Barysphere D. Divided into large tags called plates

  1. 1 - C, 2 - D, 3 - A, 4 - B

  2. 1 - D, 2 - C, 3 - A, 4 - B

  3. 1 - D, 2 - C, 3 - B, 4 - A

  4. 1 - C, 2 - D, 3 - B, 4 - A
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
1. Lithosphere D. Divided into large tags called plates 
2. Asthenosphere C. Slow speed of seismic waves in this zone 
3. Mesosphere A. The lower part of mantle
4. Barysphere B. Whole of core

Option 2 is correct.

 

Multiple choice

Consider the following statements about Mantle:

  1. It is separated from crust by Mohorovicic discontinuity.
  2. Thickness of mantle is less than half the radius of the earth.
  3. It contains more than 80% of total volume of the earth.
  4. It is separated from core by Lehman discontinuity.

Which of the given statements are true?

  1. Only 1 and 2

  2. Only 1, 2 and 3

  3. Only 1, 2 and 4

  4. Only 1, 3 and 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mohorovicic discontinuity separates mantle from crust. Earth's mantle is a rocky shell about 2,900 km thick that constitutes about 84% of Earth's volume. Note: Earth's radius is 6,400 km Lehman discontinuity separates inner core from core.

Multiple choice

Match the following:

1. Epirogenetic A. Horizontal or tangential force
2. Orogenic B. Vertical force
3. Eustatic C. Change in sea level
4. Exogenetic D. Destructive

  1. 1 - A, 2 - B, 3 - C, 4 - D

  2. 1 - B, 2 - A, 3 - C, 4 - D

  3. 1 - A, 2 - B, 3 - D, 4 - C

  4. 1 - B, 2 - A, 3 - D, 4 - C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
1. Epirogenetic B. Vertical force
2. Orogenic A. Horizontal or tangential force
3. Eustatic C. Change in sea level
4. Exogenetic D. Destructive

Epeirogenic forces are vertical forces, wherein the continents either rise or sink under the influence of these forces. Also called continent-building forces. E.g. Subsidence. Orogenic forces are horizontal forces that either push or pull rock strata. Also known as mountain-building forces. E.g. folding. Eustatic sea level changes are due to the glacial-interglacial cycle, with water being tied up in continental ice caps during glacial periods, thereby lowering the sea level, and when the ice caps melt, the water flows into the sea and raises the sea level. Exogenetic forces/agents of erosion are, generally, destructive.

Multiple choice

What causes the seismic activity in the Ring of Fire?

Directions: Read the passage carefully and answer the following question.

The Pacific Ring of Fire is the name that is given to a horseshoe shaped area in the Pacific Ocean which extends from South America and North America to Eastern Asia, Australia and New Zealand. This area is famous for its constant seismic activity and because of the amount of active volcanoes that can be found here. 75% of dormant and active volcanoes are found in the Pacific Ring of Fire. Now it is known that the area is very close to several tectonic plates which may be what influences the violent activity in the area. It is believed that the Pacific Ring of Fire has a total of 452 volcanoes. Some of the world’s most active volcanoes are found here. The volcanoes can be very dangerous to the population nearby. The Pacific Ring of Fire is different today than it was thousands of years ago because of the changes caused by tectonic plates. The Pacific Plate will hit other plates nearby and that causes them to sink. The crust melts producing the magma that feeds the different volcanoes in the Pacific Ring of Fire or it will help produce new volcanoes. The tectonic plates are the reason for the many violent earthquakes in the entire area of the pacific.

  1. Its horseshoe shape

  2. The tectonic plates in the area

  3. The number of volcanoes

  4. Cannot be determined from the passage

  5. .
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The passage says that the tectonic plates are the reason for the many violent earthquakes in the entire area of the pacific.

Multiple choice

What has caused the changes in the area of the Pacific Ring of Fire over thousands of years?

Directions: Read the passage carefully and answer the following question.

The Pacific Ring of Fire is the name that is given to a horseshoe shaped area in the Pacific Ocean which extends from South America and North America to Eastern Asia, Australia and New Zealand. This area is famous for its constant seismic activity and because of the amount of active volcanoes that can be found here. 75% of dormant and active volcanoes are found in the Pacific Ring of Fire. Now it is known that the area is very close to several tectonic plates which may be what influences the violent activity in the area. It is believed that the Pacific Ring of Fire has a total of 452 volcanoes. Some of the world’s most active volcanoes are found here. The volcanoes can be very dangerous to the population nearby. The Pacific Ring of Fire is different today than it was thousands of years ago because of the changes caused by tectonic plates. The Pacific Plate will hit other plates nearby and that causes them to sink. The crust melts producing the magma that feeds the different volcanoes in the Pacific Ring of Fire or it will help produce new volcanoes. The tectonic plates are the reason for the many violent earthquakes in the entire area of the pacific.

  1. Its horseshoe shape is remarkable and has caused the changes over thousands of years.

  2. The seismic activity due to the Pacific plate has caused the changes over thousands of years.

  3. The number of volcanoes is responsible for the changes over thousands of years.

  4. The magma in the volcanoes causes the crust to melt and causes the changes over thousands of years.

  5. .
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The passage says that the Ring of Fire is different today than it was thousands of years ago because of the changes caused by tectonic plates. The Pacific Plate will hit other plates nearby and that causes them to sink. So, we can say that the seismic activity due to pacific plate has caused the changes.