Lithosphere Class 8 Extra Questions and Answers Notes
We have provided here Lithosphere Class 8 Extra Questions and Answers Notes by our Experienced Teacher. This Extra Questions and Answers Notes consists of MCQ Questions and Answers; Very Short Type Questions and Answer & Short Type Questions and Answers.
MCQ
1.) What is the outermost solid layer of the Earth known as?
a) Atmosphere
b) Hydrosphere
c) Lithosphere
d) Mantle
Answer: c)
2.) What is the uppermost layer of the Earth’s crust called, rich in Silica and Aluminium?
a) Mantle
b) Asthenosphere
c) SIAL
d) SIMA
Answer: c)
3.) Which type of weathering involves the physical breakdown of rocks without chemical alteration?
a) Mechanical weathering
b) Chemical weathering
c) Biological weathering
d) Oxidation
Answer: a)
4.) What type of glacier is found in the polar regions and covers extensive areas?
a) Continental glacier
b) Mountain glacier
c) Valley glacier
d) Alpine glacier
Answer: a)
5.) What is the point on the Earth’s surface directly above the seismic focus of an earthquake called?
a) Epicentre
b) Hypocentre
c) Mohorovicic Discontinuity
d) Caldera
Answer: a)
6.) Which type of volcano constantly ejects lava, gases, and ashes?
a) Active volcano
b) Dormant volcano
c) Extinct volcano
d) Volcanic crater
Answer: a)
7.) Which force is responsible for changing landscape through agents like rivers, glaciers, and wind?
a) Endogenic forces
b) Exogenic forces
c) Seismic forces
d) Volcanic forces
Answer: b)
8.) What is the process by which water dissolves certain minerals in rocks and changes their composition?
a) Oxidation
b) Carbonation
c) Hydration
d) Solution
Answer: d)
9.) Which type of rock is formed by the cooling of molten matter from the Earth’s interior?
a) Sedimentary rock
b) Metamorphic rock
c) Igneous rock
d) Granite
Answer: c)
10.) What are the large, semi-circular sand deposits commonly found in desert regions called?
a) Loess
b) Rock pedestals
c) Barchans
d) Inselbergs
Answer: c)
One liners:
1.) What is the outermost solid layer of the Earth called?
Answer: Lithosphere
2.) What type of rocks are formed by the cooling of molten matter from the Earth’s interior?
Answer: Igneous rocks
3.) What is the point on the Earth’s surface directly above the seismic focus of an earthquake called?
Answer: Epicentre
4.) What is the process of changing landscape or the Earth’s surface by natural agents like rivers, glaciers, and wind called?
Answer: Denudation
5.) What is the term for the natural agent of denudation that flows from its source to its mouth along a definite course?
Answer: River
6.) What type of glacier is found in the polar regions and covers extensive areas?
Answer: Continental glacier
7.) What are the slowly moving masses of ice and snow found in high mountains and polar regions called?
Answer: Glaciers
8.) What is the subsoil water that seeps into the ground known as?
Answer: Underground water
9.) What are the semi-circular sand deposits commonly found in desert regions called?
Answer: Barchans
10.) What are the regular undulations of water on the sea or ocean called?
Answer: Sea waves
Short questions :
1.) What is the lithosphere and why is it important for life on Earth?
Answer: The lithosphere is the outermost solid layer of the earth, which consists of rocks, minerals and soils. It is essential for life on Earth because it provides a stable surface on which ecosystems can thrive and interacts with the atmosphere and hydrosphere to support life. Continents with their different landforms are part of the lithosphere and provide habitats for different life forms.
1.) What are the three main layers of the Earth’s interior and what are their characteristics?
Answer: The interior of the Earth is divided into three main layers: the crust, the mantle and the core. The earth’s crust is the silica-rich outer layer and can be continental or marine. The mantle lies below the earth’s crust and consists of semi-solid or partially molten rock material. The core is the innermost layer, composed mainly of nickel and iron, with an outer liquid layer and an inner solid core.
3.) How do earthquakes happen and what are the main causes of earthquakes?
Answer: Earthquakes are caused by a sudden release of energy in the earth’s crust, resulting in seismic waves. The main causes of earthquakes are plate tectonics, volcanic eruptions and human activity. Plate motion and interaction at plate boudaries such as subduction zones and fault lines are common triggers of earthquakes.
4.) What are the three rock types and how are they formed?
Answer: Rocks are divided into three types based on their formation processes: igneous rocks, sedimentary rocks, and metamorphic rocks. Igneous rocks form when molten material cools and solidifies. Sedimentary rocks are formed by the accumulation and cementation of sediments. Metamorphic rocks form when existing rocks are changed by heat and pressure.
5.) Explain the importance of glaciers in shaping the landscape and describe some Ice Age landforms.
Answer: Glaciers slowly move masses of ice and snow that have a major impact on the formation of the landscape. They corrode, transport and deposit materials, creating different landforms. Some glacial landforms include ridges, horns, clasts, U-shaped valleys, hanging valleys, and moraines.
6.) What are the main landforms caused by river erosion and deposition?
Answer: River erosion and deposition create several major landforms. The landforms that cause erosion are gorges, canyons, V-shaped valleys and waterfalls. Sedimentary landforms include floodplains, meanders, floodplains, natural floodplains, tributary lakes, and estuaries.
7.) How does groundwater work and what are the sources?
Answer: Aquifers are porous layers of rock that hold groundwater. The springs are natural groundwater sources. Springs can be classified into types such as perennial springs (continuous flow), intermittent springs (periodic flow), geysers (heated by geothermal activity), and geysers (periodically erupting hot springs).
8.) What role does wind play in denudation and what landforms are associated with wind erosion and deposition?
Answer: Wind promotes denudation, especially in dry desert areas. Wind erosion can create landforms such as pebbles, sponge rocks, and inselbergs. Wind deposition forms sand dunes, including longitudinal sand dunes and barcans, and deposits loess in non-desert areas.
9.) How do sea waves affect erosion and the formation of coastal landforms?
Answer: Ocean waves are a major cause of erosion and soil formation at the coast. They can erode rocks, create sea caves, sea stacks and sea trenches. Places of deposition are capes, sandbanks, beaches and lagoons.
10.) Explain the concept of plate tectonics and its relationship to the occurrence of earthquakes.
Answer: Plate tectonics is the theory that the earth’s lithosphere is divided into large plates that move and interact with each other. Earthquakes are closely related to plate tectonics because they often occur at plate boundaries, where plates either collide, move apart, or slide past each other. Stress and tension from plate movement can lead to the release of energy, causing earthquakes.
Long answer type:
1.) Question: What are the three main layers of the Earth’s interior and what are their characteristics?
Answer: The interior of the Earth consists of three main layers: the crust, the mantle and the core. The earth’s crust is the outermost layer, about 60 kilometers thick on average, and the continental crust (SIAL) is composed of silica and aluminum, and the oceanic crust (SIMA) is rich in silica and magnesium. The mantle lies beneath the earth’s crust and extends to a depth of approximately 2,900 kilometers. It contains semi-liquid or partially molten materials known as magma and consists of dense rocks with common minerals such as magnesium and iron. The core is the innermost layer at a depth of up to 6,371 kilometers and is mainly composed of nickel and iron (NIFE) and is divided into a molten outer core and a solid inner core.
2.) Question: How do glaciers affect the shape of the Earth’s landscape and what are the important landforms of glaciers?
Answer: Glaciers are the main denudation agents that affect the landscape through erosion, transport and deposition. Glaciers cause erosion by cutting sideways, creating landforms such as rocks, peaks, and U-shaped valleys. Transport and depositional processes occur simultaneously, resulting in landforms such as moraines (lateral, central, basal, and terminal areas), dykes, ridges, cameos, and margins. These landforms are characteristics of glacial regions. For example, lateral moraines are rock debris on the sides of a glacier valley, and terminal moraines are found at the end of a glacier. Drumlins are elongated hilly landforms, while ridges are made of sediments. Kamems are small hills with steep sides and plains are large extensions of glacial deposits.
3.) Describe the different types of springs and their properties.
Answer: Springs are natural groundwater sources that rise to the surface. Based on these characteristics, there are several types of springs:
– Perennial Springs: These springs release water continuously throughout the year and maintain a steady flow. – Intermittent springs: Also known as intermittent springs, water is occasionally released when periods of flow are followed by dry periods.
– Hot springs: These springs emit warm or hot water often associated with geothermal activity and are found near volcanic areas.
– Geysers: Geysers are unique hot springs that periodically erupt with jets of hot water and steam.
– Artesian wells: These are man-made wells that descend into closed bodies of water, allowing water to flow naturally to the surface without pumping.
Each spring has its own unique characteristics and geological combinations, making them important in different landscapes and ecosystems.
4.) How do rivers change the landscape in their upper, middle and lower reaches, and what landforms are associated with each stage?
Answer: Major changes occur in the upper, middle and lower reaches of rivers, resulting in different landforms:
– Sources: Rivers experience vertical erosion due to steep slopes in the sources. This leads to the formation of landforms such as V-shaped valleys, gorges, canyons and waterfalls.
– Intermediate course: In this stage, the slope of the river decreases and it receives more water from tributaries. Erosion becomes less dominant and sediment transport becomes prominent. Landforms include floodplains and meanders.
– Downstream: The slope of the river is minimal downstream and sedimentation becomes the dominant process. This phase creates landforms such as floodplains, natural floodplains, lakes and estuaries.
These landforms reflect the dynamic nature of the river systems that shape the earth’s surface.
5.) Explain the role of wind in shaping desert landscapes and the types of landforms caused by wind erosion and deposition.
Answer: Wind plays an important role in shaping desert landscapes through processes of erosion and deposition. In arid or desert regions, wind erosion occurs when high winds carry and abrade loose surface materials. The resulting landforms include plinths, sponge rocks, and inselbergs. Pedestals form when wind erosion selectively removes softer material, leaving behind harder rocks.
Wind deposition leads to the formation of sand dunes, which are the visible landforms of the desert. There are different types of sand dunes such as longitudinal sand dunes, barchans and loess deposits. Barchans are crescent-shaped dunes formed by unidirectional winds, while loess deposits consist of fine sand particles carried by the wind and deposited outside the desert boundaries.
In general, wind is a powerful agent of denudation in the desert, constantly remodeling the landscape through processes of erosion and deposition.