Maharashtra Board Class 9 Geography Solution Chapter 2 – Endogenetic Movements
Balbharati Maharashtra Board Class 9 Geography Solution Chapter 2: Endogenetic Movements. Marathi or English Medium Students of Class 9 get here Endogenetic Movements full Exercise Solution.
Std |
Maharashtra Class 9 |
Subject |
Geography (Bhugol) Solution |
Chapter |
Endogenetic Movements |
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 (Ans)
Direction
(b) When waves divert from each other, what do they create
Compression
Tension (Ans)
Mountain
(c) For the formation of a rift valley, which of the following processes should occur in the earth’s crust?
Compression
Tension (Ans)
Weathering
(d) Which of these is a fold mountain?
The Satpudas
The Himalayas (Ans)
The Western Ghats
(e) The formation of extensive plateaus is a result of which type of movements?
Mountain-building
Continent-building (Ans)
Horizontal
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 due to the movements occurring in the interior of the earth. These movements create tremendous tension in the earth’s crust and when the tension goes beyond limits, the energy is released in the form of waves. Which is the cause of trembling of the earth’s surface.
(b) There is a difference in the formation of the Meghalaya Plateau and the Deccan Plateau. Meghalaya Plateau is the example of Block Mountain which had formed because of internal movements where horizontal waves moving away from each other are created.Tension creates on the layers of rocks forms fractures in the rocks and waves coming towards each other in hard rocksform faults due to compression.A part of the earth’s crust in between two parallel faults is lifted and creates block, is known as a block mountain. The Deccan Plateau has formed due to volcanic eruption. Here lava from the Earth Crust comes out and spreads all over the plain surface. Gradually it Creates a volcanic mountains like Decan Plateau.
(c) Most of the volcanoes are found on the plate boundaries because this is the place where slides are sinking under the earth crust.There is loss of material also. Sinking plates collides with each other and the molten magma comes out of the place. That is why volcanoes are common at that place.
(d) The Barren Island is becoming conical in shape because of the active volcanoes. The continuous process of volcanic eruption has made the island conical. In Andaman and Nicobar island we can see this kind of land. Here dust, smoke and mud come out of the eruption along with some lava and made the land conical.
(e) Volcanic eruptions can cause earthquakes. When the sinking plates beneath the Earth crust heat forcefully each other the molten magma comes out of the surface. During this process high energy released and it causes earthquakes.
Q 3. Identify and name the internal movement.
(a) Tsunamis are generated in coastal areas as because Tsunamisare the effect of the sudden internal movement under the ocean.
(b) The Himalayas are an example of fold mountains because of compression. The energy waves from the interior of the earthand pressure working towards each other and in horizontal direction, the layers of the soft rocks form folds.
(c) Molten magma is thrown out of theearth’s mantle because of convection current.
(d) Rift valley is formed because of faulting and tension. When the two fractures develop side-by-side in the earth’s crust and the land in between the two fractures subsides,the deep part is called rift valley.
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 ( faultlines) rocks break apart.
(e) Stored energy is released in the form of seismic waves.
Ans) b, e, c, a, d
Q 5. Distinguish between
(a) Block Mountain and Fold Mountain
Block Mountain |
Fold Mountain |
Block Mountain is created due to Tension. |
Fold mountain is created due to compression. |
Here horizontal waves of energy moving away from each other other in a horizontal direction. |
Energy waves and pressure working towards each |
The hilltops of block mountains are flat. |
The hilltops of Fold mountains are conical. |
Black Forest mountains in Europe, The Meghalaya Plateau of India are the example of Block Mountains. |
The Himalayas, the Aravalis, the Rockies etc. are the example of Fold Mountains. |
(b) Primary and Secondary Seismic Waves
Primary Seismic Waves | Secondary Seismic Waves |
Primary Seismic Waves reach first to the surface of the earth after the energy is emitted in the earth’s interior. | It reaches after the Primary Seismic Waves. |
They travel in radial direction. | They scatter in all directions from the focus. |
These waves can travel through all the three states – liquid, solid and gaseous. | These waves can travel only through the solid Medium. |
The buildings on the earth’s surface move back and forth because of Primary Seismic. | The buildings on the earth’s surface move up and down because of these waves. |
(c) Earthquakes and volcanoes
Earthquakes | volcanoes |
Earthquakes occur in the interior of the earth. | Volcanoes are located on the plate boundaries. |
Earthquakes create sesmic waves. | Volcanoes do not create any waves. |
Q 6. Answer in brief
(a) Give reasons why an earthquake occurs.
Ans) Earthquake occurs because of colliding of the moving plates. Again in the interior of the earth fractures formation in rock layers creates tension which is the another reason of earthquake.Volcanic eruptions can also cause earthquake.
(b) Which type of movements have led to the formation of the major fold mountains in the world?
Ans) Compression movement have led to the formation of the major fold mountains in the world. Here the energy waves transferred from the interior of the earthand pressure working towards each other and in horizontal direction, the layers of the soft rocks form folds.
(c) How is the magnitude of the earthquake related to the collapse of houses?
Ans) High Magnitude creates high movement of the Earth Crust. Due to excessive vibration the houses on the earth crust collapse.
(d) What are the effects of earthquakes on the earth’s surface and human life?
Ans) Effects of earthquakes on the earth’s surface and human life are-
- Buildings collapse and loss of life and property.
- Communication system collapses after the disrupting of the transportation routes.
- Tsunamis are generated in oceans and leave its devastating effects on coastal areas. Again avalanches may occur in snow-covered areas due to Earthquakes.
- Changing in the ground water level, landslides, Cracks /fractures develop on the ground and uplifting or subsiding of some areas are the effects of earthquakes.
(e) Explain the types of seismic waves.
Ans) The seismic waves can be divided into primary, secondary and surface waves. Primary Seismic Waves reach first to the surface of the earth after the energy is emitted in the earth’s interior.They travel in radial direction. These waves can travel through allthe three states – liquid, solid and gaseous.The buildings on the earth’s surface moveback and forth because of Primary Seismicwaves. Secondary waves reach after the Primary Seismic Waves. They scatter in all directions from the focus.These waves can travel only through the solidMedium.The buildings on the earth’s surface move upand down because of these waves. After the main P and S waves the surface waves reach the epicenter and travel in the direction of the circumference of the earth along the crust.
(f) Explain the types of volcanoes on the basis of periodicity of eruption with examples.
Ans) There are two types of volcanoes on the basis of periodicity of eruption .-
- Central-type or conical volcano- Here The lava spreads around the mouth of the vent and the molten magma comes out through a pipe like vent. Due to this the shape of the volcanoes are conical. For example- Mt. Fujiyama in Japan and Mt. Kilimanjaro in Tanzania etc.
- Fissure-type volcanoes- With the single vent the magma comes out from many cracks or fissures. It creates volcanic plateaus. Deccan Plateau of India is the example of this type of volcanoes.
Not right answer