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Class 10 Geography Chapter 6 Important Questions and Answers The Changing Earth
Kerala Syllabus Class 10 Social Science Geography Chapter 6 The Changing Earth Important Questions
The Changing Earth Class 10 Important Questions
Question 1.
A hazard is generally referred to as a situation that poses a threat to which of the following?
a) Only human health
b) Only property and wealth
c) Life, health, property, services, socioeconomic stability, or the environment
d) Only the natural environment
Answer:
c) Life, health, property, services, socioeconomic stability, or the environment
Question 2.
Identify the Causative Forces of Endogenic Movements.
A. Convection currents
B. Slope of the area
C. Primordial heat
D. Gravity
a) A and C are correct
b) B and D are correct
c) C and D are correct
d) A and B are correct
Answer:
a) A and C are correct
Question 3.
Which organization has installed DART stations to detect and monitor tsunami activity?
Answer:
National Oceanic and Atmospheric Administration (NOAA)
Question 4.
Define Richter Scale.
Answer:
The scale devised by Charles F. Richter in 1935 to measure an earthquake’s magnitude is called the Richter scale.
Question 5.
Choose the correct answer by reading the given assertion and reason.
Assertion: The point inside the Earth from which the energy is released is called the focus or hypocentre.
Reason: The point on the Earth’s surface directly above the focus is called the epicentre.
a) Assertion is correct, Reason is wrong
b) Both assertion and reason are correct
c) Both assertion and reason are wrong
d) Assertion is wrong, Reason is correct
Answer:
b) Both assertion and reason are correct
Question 6.
Arrange the table suitably.
| A. The molten rock material present in the upper mantle | i. Vent |
| B. A horizontal sheet of cooled lava inside the Earth’s crust. | ii. Magma |
| C. The passage through which magma rises to the surface. | iii. Sill |
a) A – ii, B – iii, C – i
b) A – i, B – ii, C – iii
c) A – iii, B – i, C – ii
Answer:
a) A – ii, B – iii, C – i
| A. The molten rock material present in the upper mantle | ii. Magma |
| B. A horizontal sheet of cooled lava inside the Earth’s crust. | iii. Sill |
| C. The passage through which magma rises to the surface. | i. Vent |
Question 7.
Define Earth Movements.
Answer:
The movements that cause the ups and downs On the surface of the Earth are called the Earth movements.
Question 8.
Which of the following is the most destructive wave?
a) Primary waves
b) Secondary waves
c) Surface waves
d) All waves are equally destructive
Answer:
c) Surface Waves
Question 9.
Which instrument is used to record earthquake waves?
a) Barometer
b) Thermometer
c) Seismograph
d) Anemometer
Answer:
c) Seismograph
Question 10.
Distinguish between Ehdogenic and Exogenic Movements.
Answer:
Endogenic Movements: The processes that are caused by the forces within the Earth at varied intensities.
Exogenic Movements: The processes that are caused by external forces on the surface of the Earth at varied intensities.
Question 11.
What are the two classifications of Endogenic Movements?
Answer:
Diastrophic Movements and Sudden Movements
Question 12.
What are the differences between Epeirogenic and Orogenic Processes?
Answer:
Epeirogenic Processes: The processes that cause the upliftment of a large portion of the Earth’s crust are called epeirogenic movements.
Orogenic Processes: The processes that cause the formation of mountains are called orogenic movements.
Question 13.
Define Horst and Graben.
Answer:
The uplifted block of the Earth’s crust formed due to faulting is called a horst (block mountain). The corresponding down-dropped block of the Earth’s crust is called a graben.
Question 14.
Write any two Sudden Movements.
Answer:
Earthquakes and Volcanism
Question 15.
Differentiate between Volcanoes and Volcanic materials.
Answer:
The openings in the lithosphere through which molten rock material, gases, ash, pyroclastic materials (rock fragments), dust, and water vapour erupt to the surface of the Earth are called volcanoes. The materials that erupt in this way are known as volcanic materials.
Question 16.
How to mitigate the intensity and impact of natural hazards like debris flow and landslides?
Answer:
- Studies using tools like remote sensing and Geographic Information Systems (GIS) can help us identify areas that have a higher possibility of ‘UrulpottaV (debris flow or landslide).
- Institutions such as the Geological Survey of India and the National Centre for Earth Science Studies (NCESS) prepare maps of each district showing landslide/debris flow-prone areas.
Question 17.
On what basis are volcanoes classified, and what are the main types?
Answer:
Volcanoes are classified based on the nature of eruption and the formations created on the Earth’s surface. The main types are shield volcanoes, composite volcanoes, and calderas.
Question 18.
Define Volcanism.
Answer:
Volcanism is the process that includes the formation of magma, the movement of magma and other pyroclastic materials toward the surface, their eruption through holes and cracks in the lithosphere, explosions caused by the eruption, lava flow, solidification of magma, the formation of various igneous landforms, and all other associated processes.
Question 19.
How volcanic activities affect human life?
Answer:
Volcanic explosions near human settlements cause loss of lives and destruct properties. They disrupt economic activities and severely affect human life. The lava flow following a volcanic eruption adversely impacts both nature and human settlements. By destroying houses and land, it leaves many people homeless and jobless.
Question 20.
How are volcanic activities useful to humankind?
Answer:
- The geothermal energy released from volcanic regions is converted into electricity in certain areas and utilized for local purposes.
- Lava is rich in minerals, and many valuable minerals reach the surface of the Earth through the flow of lava.
- Volcanic regions often attract a large number of tourists.
Question 21.
What are the three types of Earthquake waves?
Answer:
- Primary Waves
- Secondary Waves
- Surface Waves
Question 22.
Write the Methods to safeguard ourselves from tsunamis.
Answer:
- If the sea level suddenly goes down by several metres, consider it a tsunami warning. Run away from the shore immediately and move to higher ground.
- If you are caught in a tsunami, try to save yourself by holding onto something that can float.
- Always listen to official tsunami warnings on the radio, TV, or mobile and follow evacuation instructions immediately.
Question 23.
What are the main triggering factors for debris flow?
Answer:
- Heavy rainfall
- Cloudbursts
- Earthquakes
Question 24.
Explain any causes of earthquakes other than tectonic movements?
Answer:
Earthquakes occur not only because of tectonic movements but also due to volcanic eruptions, the collapse of mine roofs in intensive mining areas, and explosions. In places where large reservoirs are situated, minor tremors are often caused by faults in the bedrock due to the pressure exerted by the water on the bedrock.
Question 25.
How to reduce the intensity of Volcanic eruption?
Answer:
- Avoid the construction of houses in areas close to volcanoes.
- Restrict tourism in such areas.
- Continuously monitor volcanic regions using scientific instruments and issuing early warnings.
- Construct buildings capable of withstanding lava flow and ash fall after an eruption.
Question 26.
Explain the Exogenic Movements and their driving forces.
Answer:
EXOGENIC MOVEMENTS
• The Exogenic forces are responsible for various processes that operate on the surface of the Earth, such as weathering, erosion, transportation, deposition, and mass wasting. These processes are collectively known as exogenic movements.
Each exogenic process derives its energy from different external forces, which are called the driving forces of exogenic movements. The nature and rate of these movements vary according to the climatic regions of the Earth.
Question 27.
What are the benefits of humans from the weathering of rocks?
Answer:
- Weathering leads to the formation of soil
- It helps to separate minerals from rocks
- It causes mineral enrichment
- It makes mining easier
Question 28.
Define KaWaCHam, and how does it help in disaster management in Kerala?
Answer:
It is a disaster warning system implemented in the state of Kerala, ensuring the use of modern technologies in disaster mitigation activities. All disaster-prone areas of Kerala are covered under this integrated warning system. Kerala is the first state in the country to implement a disaster warning system of this kind. The project aims to monitor the possibility of disasters in all areas. If any disaster is detected, the public is alerted through location- based SMS, social media updates, and by activating siren-strobe light units. Necessary precautionary measures are then taken at different levels.
Question 29.
Explain how the movement of lithospheric plates causes earthquakes.
Answer:
The reason for earthquakes is the friction between lithospheric plates. When two lithospheric plates move past each other, friction is generated along their margins. This friction in a way restricts the movement of the plates, causing high tension to build up along the margins. As a result, energy gets concentrated in these areas. When the pressure of the plates to move overcomes the friction at the plate boundaries, a sudden movement or rupture occurs at the plate boundaries. This causes energy to be released abruptly. This energy travels to the surface as seismic waves, which are experienced as earthquakes.
Question 30.
Define Weathering and explain its types.
Answer:
The Earth has different types of rocks, and they have been subjected to various changes over a long period of time. Because of certain exogenous forces, rocks are mechanically disintegrated or chemically decomposed.
• The processes that bring about these chemical and mechanical changes in rocks are called weathering.
Benefits of humans from the weathering of rocks:
- Weathering leads to the formation of soil
- It helps to separate minerals from rocks
- It causes mineral enrichment
- It makes mining easier
Question 31.
Explain the given driving forces of Exogenic Movements.
• Erosion, Transportation, Deposition
• Mass Wasting
Answer:
Erosion, Transportation, Deposition: Rock fragments formed by weathering or other processes are moved from one place to another by running water, glaciers, wind, and waves.
- Varied landforms are created by the continuous processes carried out by external agencies like running water, wind, glaciers, sea waves, etc. Hence, these agencies are often called geomorphic agents.
- The process by which running water, glaciers, wind, and waves move rock fragments from one place to another is called erosion and transportation.
- These materials will be deposited in low lying regions and this process is called deposition.
Mass Wasting: Another type of earth movement that occurs on the surface of the Earth due to exogenic forces is mass wasting. It refers to the movement or fall of rock fragments or earth materials down a slope under the direct influence of gravitational pull. It ranges from very slow movements to rapid movements. Mass wasting can vary from the sliding of a very thin layer of soil to the fall bf large quantities of earth materials.
Question 32.
What is Urulpottal and how do they occur?
Answer:
Urulpottal is a type of Mass Wasting. The landslide refers to the downward sliding of a portion of a mountain slope under the force of gravity. In the hilly regions of Kerala, intense rainfall often triggers landslides or debris flows, which may occur either separately or in combination. This phenomenon is locally known as ‘Urulpottal’ and can often be highly destructive. The possible factors that can lead to ‘Urulpottal’ in an area are the slope of the land, the depth and structure of the soil, land use, and the distribution of streams. Areas with a slope of more than 22 degrees have a higher possibility of experiencing debris flow/landslide. Debris flow and landslides are generally common in the Western Ghats and Himalayan mountains. It is estimated that the highlands of Kerala experience widespread major and minor landslides or debris flows, soil piping, and landfalls.
Question 33.
How to face Urulpottal at the time of the disaster and after the disaster?
Answer:
How To Face Urulpottal
| At the time of the disaster | After the disaster |
| • Stay calm and do not panic • During Urulpottal, if you are inside your house, take shelter under a strong table or cot. • If you are outside, move quickly to safer and higher ground, away from slopes and loose soil. |
• Allow ambulances and other rescue vehicles to pass without obstruction • Report immediately to t he authorities if you notice any fallen electric lines in LTrulpottai – affected regions. • Help people who are injured or trapped and provide first aid if possible. |
KaWaCHam: Kerala Warnings, Crisis and Hazard Management System
It is a disaster warning system implemented in the state of Kerala, ensuring the use of modem technologies in disaster mitigation activities. All disaster-prone areas of Kerala are covered under this integrated warning system. Kerala is the first state in the country to implement a disaster warning system of this kind. The project aims to monitor the possibility of disasters in all areas. If any disaster is detected, the public is alerted through location-based SMS, social media updates, and by activating siren-strobe light units. Necessary precautionary measures are then taken at different levels.