9th Social Science Lesson 12
12] Lithosphere – I Endogenetic Processes
Book Back Questions with Answer and Do You Know Box Content
Do You Know?
“The Earth can physically be described as a ball of rock (the lithosphere) , partly covered by water (the hydrosphere) and wrapped in an envelope of air (the atmosphere) . To these three physical zones it is convenient to add a biological zone which includes all the living organisms (the biosphere) ”.
The lithosphere is the solid outer part of the Earth. The atmosphere is a thin layer of gases that surrounds the Earth. The hydrosphere is the watery part of the Earth’s surface including oceans, rivers, lakes and water vapour. The biosphere is the layer of Earth where life exists.
The terms ‘lithosphere’ and ‘crust’ are not the same. The lithosphere includes the crust and the uppermost part of the mantle. All terrestrial planets have lithosphere. The lithospheres of Mercury, Venus, and Mars are much thicker and more rigid than that of the Earth.
The ancient city of Petra in Jordan is an example of an entire city carved out of rocks. There are many specimens of magnificent rock-cut architecture in India, like the Ajanta and Ellora caves in Maharashtra, the Aihole and Badami temples in Karnataka, the Konark temple in Odisha and Mamallapuram in Tamil Nadu.
The Deepest Place ever reached by human technology vary from time to time. Till 2011 Kola Super Hole (12,262m) in Murmansk, Russia was the deepest place. But in 2012, Z-44 Chavyo Well (12,376m) broke the record, and is supposed to be 15 times the height of Burj Khalifa in Dubai. The exploration of Earth’s interior continues.
C.F. Richter devised a scale to measure the magnitude of Earthquakes. This scale relates to the energy released at the epicentre and provides an estimation of the severity of an Earthquake. It is an open ended scale. The highest magnitude ever recorded is 9.5 on Richter scale (Bio-Bio, Chile in 1960) .
The instrument which records the Earthquake waves is called ‘seismograph’ or ‘seismometer’. The science that deals with Earthquakes is called ‘seismology’.
The term ‘volcano’ is derived from the Latin term VULCAN, which is the name of Roman ‘God of Fire’.
On 26 December 2004 a tsunami occurred in the Indian Ocean. It was the result of the Indio-Australian Plate subducting below the Eurasian Plate. It was caused by an Earthquake measuring a magnitude of above 9 in the Richter scale. The Earthquake caused the seafloor to uplift, displacing the seawater above.
Choose the best answers:
1. ______________ is the rigid outer layer of the Earth.
(d) Inner core
2. __________ layer is made up of liquid iron.
(a) Inner core
(b) Outer core
3. Magma is found in the _____________
(d) None of the above
4. The movement of tectonic plates is induced by ______________ energy.
5. In the ancient period, Gondwanaland moved towards _____________ direction.
6. Many million years ago, India was a part of the super continent _____________
7. The movement of plates that creates stress and tension in the rocks causing them to stretch and cracks result in ___________
8. ___________ refers to bowl-shaped depression found at the top of the volcano.
(d) Volcanic cone
9. The point of origin of an Earthquake is called the ______________
(c) Seismic wave
Match the following:
1. Endogenetic process – Seismograph
2. Mantle – Subduction Zone
3. Convergent boundaries – Volcanic Eruption
4. Earthquake – Pacific Ocean
5. Composite Volcano – SIMA
Consider the following the statements and tick the appropriate answer:
1. i. Mt. Fuji is a dormant volcano.
ii. Mt. Kilimanjaro is a dormant volcano.
iii. Mt. Tanzania is a dormant volcano. Which of the statement(s) is/are true?
(a) i is true
(b) ii is true
(c) iii is true
(d) i, ii, iii are true
2. Statement: Magma gushes out when it finds vents.
Reason: Interior of the Earth contains compressed hot Magma
(a) Statement & reason are true
(b) Statement is true, reason is false
(c) Statement is false reason is true
(d) Statement & reason are false
3. Statement I: Mountain ranges are formed by the collision of tectonic plates.
Statement II: The movement of tectonic plates is due to the thermal energy from the mantle.
(a) Statement I is false II is true
(b) Statement I and II are false
(c) Statement I is true II is false
(d) Statement I and II are true
Choose the correct answers:
1. Crust 2. Outer core 3. Mantle 4. Thermal 5. North 6. Gondwana 7. Fault 8. Crater 9. Focus
Match the following:
1. Volcanic Eruption 2. SIMA 3. Subduction zone 4. Seismograph 5. Pacific Ocean
Consider the following statements and choose the correct answer:
1. Statement i is true.
2. Both Statement and Reason is true.
3. Statement I and II are true