The Class 9 is an important year in a student’s life and Maharashtra State Board Social Science Geography is one of the subjects that require dedication, hard work, and practice. It’s a subject where you can score well if you are well-versed with the concepts, remember the important formulas and solving methods, and have done an ample amount of practice. Worry not! Home Revise is here to make your Class 9 journey even easier. It’s essential for students to have the right study material and notes to prepare for their board examinations, and through Home Revise, you can cover all the fundamental topics in the subject and the complete Maharashtra State Board Class 9 Social Science Geography Book syllabus.
Q 1. Tick in front of the correct option
(a) On which of the following are slow movements in the earth’s interior dependent?
Landforms
Velocity
Direction
(b) When waves divert from each other, what do they create?
Compression
Tension
Mountain
(c) For the formation of a rift valley, which of the following processes should occur in the earth’s crust?
Compression
Tension
Weathering
(d) Which of these is a fold mountain?
The Satpudas
The Himalayas
The Western Ghats
(e) The formation of extensive plateaus is a result of which type of movements?
Mountain-building
Continent-building
Horizontal
Answer a: Velocity
Answer b: Tension
Answer c: Tension
Answer d: The Himalayas
Answer e: Continent-building
Q 2. Give geographical reasons
(a) Buildings collapsed at the foothills of the Himalayas because of an earthquake. Before collapsing they were moving forward and backward.
(b) There is a difference in the formation of the Meghalaya Plateau and the Deccan Plateau.
(c) Most of the volcanoes are found on the plate boundaries.
(d) The Barren Island is becoming conical in shape.
(e) Volcanic eruptions can cause earthquakes.
Answer a: Buildings collapsed at the foothills of Himalayas because of an earthquake, but before collapsing they were moving backward and forward because in hilly areas there is always rearrangement of earth plates under hills. If any major change occurs, it leads to an earthquake, in which forward and backward movement in buildings is seen.
Answer b: The internal movements of tension lead to the formation of fractures in the rocks. These fractures are called faults. When a part of the earth crust between two falls is lifted, it forms a block mountain. Meghalaya plateau is an example of such a movement. Deccan Plateau has been formed due to the fissure type volcano where the lava comes out of the crack in the earth crust and spreads all around forming a flat surface. Therefore, there is a difference in the formation of Meghalaya plateau and Deccan Plateau.
Answer c: Most of the volcanoes are very commonly found along the boundaries of the tectonic plates because this is where the sinking of the oceanic plates beneath other plates take place. These plates sink and begin heating after going into the Subduction Zone where they melt and the formation of magma takes place. Volcanoes are common there so that when the plates are pulled apart the magma can rise from the bottom of the earth ’s mantle.
Answer d: Barren island is known as India ’s only active volcanic land. It is located in Andaman and Nicobar. In January some scientist noticed a difference in the shape of the Barren island as it has started to show the signs of a volcanic eruption.When a volcano is about to occur,The shape of land starts to become conical.
Answer e: While undergoing the process of the volcanic eruption, the plates which are present underneath the earth ’s surface sinks below to another plate. The process of sinking is also called subduction. The process creates magma and produces a heavy amount of heat. The process will eventually move to magma very violently which causes the eruption and rises to the surface. Now when the magma reaches the surface it causes volcanoes. Activities occur underneath the surface refereeing with plates which is the reason it causes an earthquake.
Q 3. Identify and name the internal movement.
(a) Tsunamis are generated in coastal areas.
(b) The Himalayas are an example of fold mountains.
(c) Molten magma is thrown out of the earth’s mantle.
(d) Rift valley is formed because of faulting.
Answer a: Tsunamis are caused due to sudden internal movements within the earth’s crust below the ocean floor that lead to earthquakes and volcanic eruptions.
Answer b: Himalayas are formed by compression that lead to folding of the softer rocks.
Answer c: Molten magma is thrown out to earth ’s mantle. The type of internal movement is convection currents. The plates diverge due to the pressure created by the currents. This causes the magma to be thrown out to the earth ’s crust.
Answer d: A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading part of the surface, which is subsequently further deepened by the forces of erosion.
Q 4. Arrange the following statements in chronological order in which an earthquake occurs.
(a) The earth’s surface vibrates
(b) The plates suddenly move.
(c) Due to the movements in the mantle, compression goes on increasing.
(d) Along the weak points ( fault lines) rocks break apart.
(e) Stored energy is released.
Answer: (b) The plates suddenly move.
(e) Stored energy is released in the form of seismic waves.
(c) Due to the movements in the mantle, compression goes on increasing.
(a) The earth’s surface vibrates
(d) Along the weak points (fault lines) rocks break apart.
Q 5. Distinguish between
(a) Block Mountain and Fold Mountain
(b) Primary and Secondary Seismic Waves
(c) Earthquakes and volcanoes
Answer a:
| Block Mountain | Fold Mountain |
| Block mountains are formed due to faulting. | Fold mountains are formed due to folding of the rocks. |
| Block Mountains are formed when the two tectonic plates move away from each other causing cracks on the surface of the Earth. | Fold Mountains are formed when two tectonic plates move towards each other leading to the folding of the layers of the Earth. |
| Block mountains are generally wider in length as compared to the fold mountains. | Fold mountains are greater in length but comparatively smaller in width |
| Example: Black Forest Mountains in Germany. | Example: The Himalayas |
Answer b:
| Primary Seismic Waves | Secondary Seismic Waves |
| Primary Waves are also called P waves or Push waves, travel the fastest and thus are the first to arrive. Travelling at an average speed of 6 km per/s, these waves cause relatively smaller displacement (low tremors). | Secondary waves or S waves or Shake waves, arrive the next, moving at lesser speeds than the P waves. These waves produce a strong shaking effect. These do not pass through liquids. |
Answer c: The difference between volcano and earthquake:
Volcanoes occur at the planetary surface whereas earthquakes occur in the interior part of the earth crust.
Volcanoes always form new rocks whereas earthquakes release seismic waves.
Volcano can be predicted before eruption but earthquakes cannot be determined in a fixed time frame.
Volcanoes always produce the ash and debris whereas earthquakes produce only debris due to the disturbance on the earth crust.
Q 6. Answer in brief
(a) Give reasons why an earthquake occurs.
(b) Which type of movements have led to the formation of the major fold mountains in the world?
(c) How is the magnitude of the earthquake related to the collapse of houses
(d) What are the effects of earthquakes on the earth’s surface and human life?
(e) Explain the types of seismic waves.
(f) Explain the types of volcanoes on the basis of periodicity of eruption with examples.
Answer a: Earthquakes: Owing to the movements occurring in the interior of the earth, tremendous tension is created in the earth’s crust. When the tension goes beyond limits, the energy is released in the form of waves. This results in trembling of the earth’s surface, i.e. earthquakes occur. The magnitude of the earthquake is measured by the Richter scale.
Answer b: Energy is transferred from the interior of the earth. Because of these energy waves and pressure working towards each other and in horizontal direction, the layers of the soft rocks form folds. If the pressure is very high, large scale folds are formed and their complexity increases. As a result, the surface of the earth gets uplifted and fold mountains are formed.
Answer c: If the magnitude of the earthquake is high, that means there will be more vibration and shaking of the ground which will disturb the foundation of the buildings. Higher the shaking, higher is the chance of the buildings collapsing.
Answer d: The earthquakes had several effects on the human lives as well as the surface of the earth. This particular phenomenon causes several damage to human life. The primary effects of earthquakes are many like landslides, ground rupture and ground shaking. Sometimes it can lead to liquefaction as well as Tsunamis. There are also some secondary effects of the earthquakes like fire. It can also damage the houses as well as important places like offices and malls.
Answer e: Earthquakes generate three types of seismic waves: P (primary) waves, S (secondary) waves and surface waves. Both P and S waves penetrate the interior of the Earth while surface waves do not. Due to this, P and S waves are known as “body waves ”. Surface waves arrive last and are the least interesting to seismic tomography because they don ’t penetrate deep inside the Earth, therefore provide little information about inaccessible terrain.
Answer f: On the basis of the type of eruption, volcanoes can be divided into the following types:
Central-type or conical volcano: During eruption, the molten magma comes out through a pipe-like vent inside the earth’s surface. The lava spreads around the mouth of this vent when it comes out. As a result, cone shaped mountains start forming and conical volcanic mountains are formed. Mt. Fujiyama in Japan and Mt. Kilimanjaro in Tanzania are examples of central-type volcanoes and conical mountains.
Fissure-type volcanoes: During eruption, when the magma comes out not from a single vent but from many cracks (fissures), it is called fissure-type volcanic eruption. The molten material coming out with the eruption spreads on both the sides of the fissure. As a result, volcanic plateaus are formed. The Deccan Plateau of India has also been formed due to such a type of volcanic eruption.
Q 7. Show the epicentre, focus and the primary, secondary and surface waves of an earthquake with the help of a neat labelled diagram.
Q 8. Show the following on a given outline map of the world.
(a) Mt. Kilimanjaro
(b) Mid-Atlantic Earthquake zone
(c) Mt. Fuji
(d) Krakatoa
(e) Mt. Vesuvius
