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English · हिन्दी · తెలుగు · தமிழ் · മലയാളം · मराठी · ಕನ್ನಡ

Quick recap: geomorphology on one page

ಕನ್ನಡದಲ್ಲಿ ವಿವರಣೆ

Geomorphology: plates, earthquakes, volcanoes and landforms · Quick recap · Fact-checked on · how we check

Written with AI from the sources listed at the bottom of this page, then fact-checked by a separate AI.

All four parts condensed for quick revision: drift, sea-floor spreading and plate tectonics, earthquakes, tsunamis and volcanoes, weathering, mass movement and rivers, and the landforms of glaciers, wind, groundwater and waves, with a one-table overview and eight mixed questions.

Each idea is explained first in Kannada (ಕನ್ನಡ), ending with the English and Hindi exam terms, followed by the same point in exam English. UPSC Prelims is in English or Hindi, so understand it in Kannada and revise it in English.

ಭೂಮಿಯ ಮೇಲ್ಮೈಯನ್ನು ಎರಡು ವಿರುದ್ಧ ಶಕ್ತಿಗಳು ರೂಪಿಸುತ್ತವೆ — ಒಂದು ಇಟ್ಟಿಗೆ ಪೇರಿಸುವ ಮೇಸ್ತ್ರಿ, ಇನ್ನೊಂದು ಅವನ್ನು ಸವೆಸುವ ಮಳೆ. ಅಂತರ್ಜನ್ಯ ಬಲಗಳು ಒಳಗಿನ ಶಾಖದಿಂದ ಫಲಕಗಳನ್ನು ಸರಿಸಿ, ಬೆಟ್ಟ ಎತ್ತಿ, ಭೂಕಂಪ, ಜ್ವಾಲಾಮುಖಿ ತರುತ್ತವೆ. ಬಹಿರ್ಜನ್ಯ ಬಲಗಳು ಸೂರ್ಯಶಕ್ತಿ, ಗುರುತ್ವದಿಂದ ಅವನ್ನು ಸವೆಸುತ್ತವೆ. ಭಾಗ 1: ಫಲಕಗಳು; ಭಾಗ 2: ಭೂಕಂಪ, ಜ್ವಾಲಾಮುಖಿ; ಭಾಗ 3: ಶಿಥಿಲೀಕರಣ, ನದಿಗಳು; ಭಾಗ 4: ಹಿಮ, ಗಾಳಿ, ಅಂತರ್ಜಲ, ಅಲೆಗಳು. (→ English: endogenic forces, exogenic forces · हिन्दी: अंतर्जात बल, बहिर्जात बल)

In exam EnglishThis chapter explains how the Earth's surface is shaped by two opposing sets of forces. endogenic forces, driven by the Earth's internal heat, build relief: they move plates, raise mountains, and cause earthquakes and volcanoes. exogenic forces, driven by the Sun's energy and gravity, wear that relief down through weathering, erosion and deposition. Part 1 covers drift and plate tectonics, Part 2 earthquakes, tsunamis and volcanoes, Part 3 weathering, mass movement and rivers, and Part 4 glaciers, wind, groundwater and waves.

1912ರಲ್ಲಿ ವೆಗೆನರ್ ಖಂಡಾಂತರ ಚಲನೆ ಹೇಳಿದ — ಖಂಡಗಳು ಒಮ್ಮೆ ಪ್ಯಾಂಜಿಯಾವಾಗಿ ಅಂಟಿಕೊಂಡಿದ್ದವು, ನಂತರ ಲಾರೇಶಿಯಾ, ಗೊಂಡ್ವಾನಾಲ್ಯಾಂಡ್ ಆಗಿ ಒಡೆದವು; ಭಾರತ ಗೊಂಡ್ವಾನಾದಲ್ಲಿ. ಹರಿದ ಕಾಗದದ ತುಂಡುಗಳನ್ನು ಜೋಡಿಸಿದಂತೆ ತೀರಗಳು ಹೊಂದುವುದು, ಒಂದೇ ಬಗೆಯ ಕಲ್ಲುಗಳು, ಪಳೆಯುಳಿಕೆಗಳು ಸಾಕ್ಷ್ಯ; ಆದರೆ ಸರಿಸುವ ಶಕ್ತಿ ಹೇಳಲಾಗಲಿಲ್ಲ. ಹೋಮ್ಸ್ ಸಂವಹನ ಪ್ರವಾಹ, ಹೆಸ್ ಸಾಗರತಳ ವಿಸ್ತರಣೆ ಹೇಳಿದರು — ಏಣುಗಳಲ್ಲಿ ಹೊಸ ತಳ, ಕಂದಕಗಳಲ್ಲಿ ನಾಶ; ಹಾಗಾಗಿ ಸಾಗರತಳ ಸುಮಾರು 20 ಕೋಟಿ ವರ್ಷಕ್ಕಿಂತ ಹಳೆಯದಲ್ಲ. (→ English: continental drift, sea-floor spreading · हिन्दी: महाद्वीपीय विस्थापन, सागर नितल प्रसरण)

In exam EnglishIn 1912 Alfred Wegener put forward continental drift, arguing that the continents were once joined as Pangaea, with a single ocean, Panthalassa, around it; Pangaea broke into Laurasia and Gondwanaland, and India was part of Gondwanaland. His evidence included the fit of the Atlantic coasts, matching rocks and tillite, and fossils such as Mesosaurus and Glossopteris, but his proposed forces were too weak. Holmes suggested mantle convection in the 1930s, and Hess explained sea-floor spreading in the early 1960s, confirmed by symmetrical magnetic stripes: new crust forms at mid-ocean ridges and is destroyed at trenches, so no ocean floor is older than about 200 million years.

ಭೂಫಲಕ ಸಿದ್ಧಾಂತ ಪ್ರಕಾರ ಭೂಮಿಯ ಹೊರಕವಚ ಏಳು ದೊಡ್ಡ, ಅನೇಕ ಸಣ್ಣ ಫಲಕಗಳಾಗಿ ಒಡೆದು, ವರ್ಷಕ್ಕೆ ಕೆಲವು ಸೆಂಟಿಮೀಟರ್ ಸರಿಯುತ್ತದೆ — ಒಡೆದ ಮೊಟ್ಟೆಯ ಚಿಪ್ಪಿನ ತುಂಡುಗಳಂತೆ. ದೂರ ಸರಿಯುವಲ್ಲಿ ಹೊಸ ತಳ; ಹತ್ತಿರ ಬರುವಲ್ಲಿ ಅಧೋಗಮನ ಅಥವಾ ಡಿಕ್ಕಿ; ಪಕ್ಕಪಕ್ಕ ಉಜ್ಜುವಲ್ಲಿ ಏನೂ ಹುಟ್ಟುವುದಿಲ್ಲ, ನಾಶವಾಗುವುದಿಲ್ಲ. ಸಾಗರ–ಖಂಡ ಡಿಕ್ಕಿಯಾದರೆ ಆಂಡಿಸ್‌ನಂತಹ ಜ್ವಾಲಾಮುಖಿ ಶ್ರೇಣಿ; ಖಂಡ–ಖಂಡ ಡಿಕ್ಕಿಯಾದರೆ ಜ್ವಾಲಾಮುಖಿ ಇಲ್ಲದ ಮಡಿಕೆ ಪರ್ವತ. ಭಾರತ ಉತ್ತರಕ್ಕೆ ಸರಿದು, ದಖ್ಖನ್ ಟ್ರ್ಯಾಪ್ ರೂಪುಗೊಂಡು, ಏಷ್ಯಾಕ್ಕೆ ಡಿಕ್ಕಿ ಹೊಡೆದು ಹಿಮಾಲಯ ಎದ್ದಿತು — ಈಗಲೂ ಏರುತ್ತಿದೆ. (→ English: plate tectonics, subduction · हिन्दी: प्लेट विवर्तनिकी, अधोगमन)

In exam Englishplate tectonics, developed in the late 1960s, treats the lithosphere as seven major plates and many minor ones moving a few centimetres a year over the asthenosphere. Divergent (constructive) boundaries create crust at ridges and rifts; convergent (destructive) boundaries destroy it by subduction or crumple it in collisions; transform (conservative) boundaries such as the San Andreas Fault neither create nor destroy crust. Ocean-continent subduction builds volcanic ranges like the Andes, ocean-ocean subduction builds trenches and island arcs, and continent-continent collision builds fold mountains without active volcanoes. India drifted north from Gondwanaland over the Réunion hotspot, which produced the Deccan Traps, and its collision with Asia raised the Himalaya, which is still rising.

ಭೂಕಂಪ ಎಂದರೆ ಕಲ್ಲುಗಳಲ್ಲಿ ಸಂಗ್ರಹವಾದ ಶಕ್ತಿ ಒಮ್ಮೆಲೇ ಬಿಡುಗಡೆಯಾಗುವುದು — ಹೆಚ್ಚು ಎಳೆದ ಸ್ಪ್ರಿಂಗ್ ಬಿಟ್ಟಂತೆ. ಒಳಗೆ ಶುರುವಾಗುವ ಜಾಗ ಕೇಂದ್ರ; ಅದರ ನೇರ ಮೇಲೆ ನೆಲದಲ್ಲಿ ಅಧಿಕೇಂದ್ರ. ಪ್ರಮಾಣ ಒಂದೇ ಸಂಖ್ಯೆ (ಶಕ್ತಿ); ತೀವ್ರತೆ ಊರಿಂದೂರಿಗೆ ಬದಲಾಗುತ್ತದೆ (ಹಾನಿ). ಸುನಾಮಿ ಆಳ ಸಮುದ್ರದಲ್ಲಿ ವೇಗವಾಗಿ, ತಗ್ಗಾಗಿ ಹೋಗಿ ತೀರದ ಬಳಿ ದೊಡ್ಡದಾಗುತ್ತದೆ; 2004ರ ನಂತರ ಹೈದರಾಬಾದ್‌ನಲ್ಲಿ ಎಚ್ಚರಿಕೆ ಕೇಂದ್ರ. ಭಾರತದಲ್ಲಿ ವಲಯಗಳು II ರಿಂದ V. (→ English: earthquake, epicentre, tsunami · हिन्दी: भूकंप, अधिकेंद्र, सुनामी)

In exam EnglishAn earthquake is a sudden release of energy stored in rocks, usually by slip along a fault. The focus is where rupture begins and the epicentre is the point on the surface directly above it. Magnitude (Richter or moment magnitude) is a single logarithmic measure of energy; intensity (Modified Mercalli, I to XII) describes effects and varies from place to place. A tsunami is fast but low in deep water and grows tall only near the coast; after the 2004 Indian Ocean tsunami, India set up its warning centre at INCOIS, Hyderabad. Earthquakes cluster along the Circum-Pacific belt, the Alpine-Himalayan belt and the mid-ocean ridges, and India's seismic zones run from II to V under IS 1893 (Part 1): 2016.

ಜ್ವಾಲಾಮುಖಿ ಎಂದರೆ ಶಿಲಾಪಾಕ ಲಾವಾ, ಅನಿಲ, ಬೂದಿಯಾಗಿ ಹೊರಬರುವ ಬಾಗಿಲು. ತೆಳು ಲಾವಾ — ಜೇನು ಸುರಿದಂತೆ ನಿಧಾನವಾಗಿ ಹರಿದು ಗುರಾಣಿ ಆಕಾರ (ಹವಾಯಿ); ದಪ್ಪ ಲಾವಾ — ಸೋಡಾ ಬಾಟಲಿ ಅಲುಗಿಸಿ ತೆರೆದಂತೆ ಸ್ಫೋಟ (ಫ್ಯೂಜಿ). ದಖ್ಖನ್ ಟ್ರ್ಯಾಪ್ ಬಿರುಕುಗಳಿಂದ ಪ್ರವಾಹದಂತೆ ಹರಿದ ಲಾವಾ. ಒಳಗೇ ತಣ್ಣಗಾದರೆ ಬ್ಯಾಥೋಲಿತ್, ಸಿಲ್ (ಪದರಗಳಿಗೆ ಸಮಾಂತರ), ಡೈಕ್ (ಪದರಗಳನ್ನು ಅಡ್ಡ ಕತ್ತರಿಸಿ). ಅಂಡಮಾನ್ ಸಮುದ್ರದ ಬ್ಯಾರನ್ ದ್ವೀಪ ನಮ್ಮ ಏಕೈಕ ಸಕ್ರಿಯ ಜ್ವಾಲಾಮುಖಿ; ನಾರ್ಕೊಂಡಂ ಸುಪ್ತ. (→ English: volcano, magma · हिन्दी: ज्वालामुखी, मैग्मा)

In exam EnglishA volcano is an opening through which magma reaches the surface as lava, gases and ash. Volcanoes form at subduction zones, at mid-ocean ridges and over hotspots. Shield volcanoes, built of fluid basalt, erupt gently, as in Hawaii; composite volcanoes, built of viscous, silica-rich lava, erupt explosively, as at Fuji; calderas form when a volcano's summit collapses; and flood basalts such as the Deccan Traps pour from fissures. Magma that cools below the surface forms intrusive bodies such as batholiths, laccoliths, lopoliths and phacoliths; sills spread out between rock layers, whereas dykes slice across them. Barren Island in the Andaman Sea is India's only active volcano, and Narcondam is dormant.

ಶಿಥಿಲೀಕರಣ ಕಲ್ಲನ್ನು ಇದ್ದಲ್ಲೇ ಒಡೆಯುತ್ತದೆ — ಭೌತಿಕ, ರಾಸಾಯನಿಕ, ಜೈವಿಕ; ಬಿಸಿ-ತೇವದ ಕಡೆ ರಾಸಾಯನಿಕ ವೇಗ. ನಂತರ ರಾಶಿ ಚಲನೆ ಗುರುತ್ವದಿಂದ ಅದನ್ನು ಕೆಳಗೆ ಜಾರಿಸುತ್ತದೆ — ನಿಧಾನ ಸರಿಯುವಿಕೆಯಿಂದ ಹಠಾತ್ ಭೂಕುಸಿತದವರೆಗೆ; ಹಿಮಾಲಯ, ಪಶ್ಚಿಮ ಘಟ್ಟಗಳಲ್ಲಿ ಹೆಚ್ಚು. ನದಿ ಮೇಲ್ಭಾಗದಲ್ಲಿ 'V' ಕಣಿವೆ, ಜಲಪಾತ ಕೊರೆಯುತ್ತದೆ; ಕೆಳಗೆ ಬಂದಾಗ ಹಾವಿನಂತೆ ಬಳುಕಿ ಬಯಲು ಕಟ್ಟುತ್ತದೆ. ಹೂಳು ಹೆಚ್ಚಾದರೆ ಮುಖಜಭೂಮಿ (ಗೋದಾವರಿ, ಕೃಷ್ಣಾ); ಉಬ್ಬರ ಕೊಚ್ಚಿಕೊಂಡು ಹೋದರೆ ನದೀಮುಖ (ನರ್ಮದಾ, ತಾಪಿ). (→ English: weathering, mass movement, delta · हिन्दी: अपक्षय, वृहत् संचलन, डेल्टा)

In exam Englishweathering breaks rock down in place, physically (frost wedging, heating and cooling, exfoliation), chemically (carbonation, oxidation, hydrolysis) or biologically; chemical weathering is fastest in hot, wet climates. mass movement then carries loosened material downslope under gravity, from slow soil creep to sudden landslides, which are most frequent in the Himalaya and the Western Ghats. Rivers erode most in their steep upper course, cutting V-shaped valleys, gorges and waterfalls; in the gentler middle and lower course they swing into meanders, leave ox-bow lakes, and build floodplains, levees and alluvial fans. Where sediment outpaces the sea a river builds a delta, as the Godavari and Krishna do; where tides scour it away, as for the Narmada and Tapi, it ends in an estuary.

ಉಳಿದ ಶಕ್ತಿಗಳದ್ದೂ ಅದೇ ನಿಯಮ — ರಭಸ ಇದ್ದರೆ ಸವೆತ, ಕುಗ್ಗಿದರೆ ಬಿಡುವುದು. ಹಿಮನದಿ ಸರ್ಕ್, ಹಾರ್ನ್, 'U' ಕಣಿವೆ, ಫಿಯಾರ್ಡ್ ಕೆತ್ತಿ, ಜರಡಿ ಹಿಡಿಯದ ಮೊರೇನ್ ಬಿಡುತ್ತದೆ; ಅದರ ಕರಗಿದ ನೀರು ಜರಡಿ ಹಿಡಿದ ಮರಳು ಹರಡುತ್ತದೆ. ಮರುಭೂಮಿಯ ಗಾಳಿ ಅಣಬೆ ಕಲ್ಲು, ಬರ್ಕಾನ್ ದಿಬ್ಬ ಮಾಡುತ್ತದೆ. ಸುಣ್ಣದಕಲ್ಲು ಕರಗಿಸುವ ನೀರು ಕಾರ್ಸ್ಟ್ ಭೂಲಕ್ಷಣ, ಗುಹೆಗಳಲ್ಲಿ ಸ್ಟಾಲಕ್ಟೈಟ್-ಸ್ಟಾಲಗ್ಮೈಟ್. ಅಲೆಗಳು ಕ್ಲಿಫ್, ಸ್ಟ್ಯಾಕ್ ಕೊರೆದು, ಮರಳದಂಡೆ, ಚಿಲಿಕಾದಂತಹ ಲಗೂನ್ ಕಟ್ಟುತ್ತವೆ. (→ English: glacier, moraine, karst topography · हिन्दी: हिमनद, हिमोढ़, कार्स्ट स्थलाकृति)

In exam EnglishThe other agents repeat the same pattern of erosion where energy is high and deposition where it falls. A glacier carves cirques, arêtes, horns, U-shaped and hanging valleys and fjords, and drops unsorted till as moraines and drumlins, while its meltwater leaves sorted eskers and outwash plains. Wind in deserts makes deflation hollows and mushroom rocks and piles sand into barchans and seif dunes, with fine silt settling far away as loess. In limestone, dissolving groundwater creates karst topography with sinkholes, uvalas and poljes, and caves decorated by stalactites and stalagmites. Waves cut cliffs, arches and stacks and build beaches, spits, bars and lagoons such as Chilika. The table below gathers the facts most often tested.
The chapter at a glance
TopicMust-know factsCommon trap
Drift and spreadingWegener 1912; Holmes 1930s (convection); Hess early 1960s (spreading)India was in Gondwanaland, not Laurasia
Plate boundariesDivergent = constructive; convergent = destructive; transform = conservativeHimalaya (collision) has no active volcanoes
EarthquakesFocus inside, epicentre above; magnitude one number, intensity variesNo Zone I in India; zones II to V
VolcanoesShield (fluid basalt, gentle); composite (viscous, explosive)Deccan Traps are flood basalt, not a shield volcano
RiversV-valleys and waterfalls upstream; meanders, ox-bows, deltas downstreamNarmada and Tapi form estuaries, not deltas
Ice, wind, karst, wavesMoraines unsorted; barchan horns downwind; stalactites hangFjord = drowned glacial valley; ria = drowned river valley

Exam traps

Recap

Practice questions

Q1. Who among the following explained the theory of sea-floor spreading in the early 1960s?

  1. Alfred Wegener
  2. Arthur Holmes
  3. Harry Hess
  4. Charles Richter
Show answer

Answer: C. Harry Hess

Harry Hess proposed sea-floor spreading in the early 1960s. Wegener proposed continental drift in 1912, Holmes suggested mantle convection currents in the 1930s, and Richter devised an earthquake magnitude scale.

Q2. Consider the following statements:
1. At transform plate boundaries, crust is neither created nor destroyed.
2. A continent-continent collision typically produces chains of active volcanoes.
Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2
Show answer

Answer: A. 1 only

Statement 1 is correct: transform boundaries are conservative. Statement 2 is wrong: collisions such as the one that built the Himalaya produce fold mountains without active volcanoes. So (b) and (c) accept the wrong statement and (d) rejects the correct one.

Q3. With reference to earthquakes, which one of the following statements is correct?

  1. The epicentre is the point inside the Earth where rupture begins.
  2. Intensity of an earthquake is the same at every place it is felt.
  3. A tsunami is low in deep water and grows tall near the coast.
  4. India's seismic zones range from I to V.
Show answer

Answer: C. A tsunami is low in deep water and grows tall near the coast.

Option (c) is correct. The point where rupture begins is the focus, not the epicentre; intensity varies from place to place; and India's zones run from II to V, with no Zone I.

Q4. Which one of the following is India's only active volcano?

  1. Narcondam
  2. Barren Island
  3. Deccan Traps
  4. Manikaran
Show answer

Answer: B. Barren Island

Barren Island in the Andaman Sea is India's only active volcano. Narcondam is dormant, the Deccan Traps are ancient flood basalts, and Manikaran is known for hot springs, not a volcano.

Q5. Which of the following rivers end in estuaries rather than deltas?
1. Narmada
2. Tapi
3. Godavari
Select the correct answer using the code given below:

  1. 1 and 2 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
Show answer

Answer: A. 1 and 2 only

The west-flowing Narmada and Tapi end in estuaries. The Godavari builds a delta on the east coast, so every option including 3, namely (b), (c) and (d), is wrong.

Q6. Consider the following statements:
1. Weathering involves the transport of rock material away from its source.
2. Chemical weathering is fastest in hot and humid climates.
Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2
Show answer

Answer: B. 2 only

Statement 1 is wrong: weathering happens in place, while transport is erosion. Statement 2 is correct. So (a) and (c) accept the wrong statement and (d) rejects the correct one.

Q7. Match List I (landform) with List II (agent):
List I
A. Esker
B. Barchan
C. Uvala
D. Tombolo
List II
1. Waves
2. Groundwater
3. Wind
4. Glacial meltwater
Select the correct answer using the code given below:

  1. A-4, B-3, C-2, D-1
  2. A-3, B-4, C-2, D-1
  3. A-4, B-3, C-1, D-2
  4. A-2, B-3, C-4, D-1
Show answer

Answer: A. A-4, B-3, C-2, D-1

Eskers are laid down by glacial meltwater, barchans by wind, uvalas by groundwater dissolving limestone, and tombolos by waves: A-4, B-3, C-2, D-1. Option (b) swaps the esker and barchan, (c) swaps the uvala and tombolo, and (d) gives the esker to groundwater and the uvala to meltwater.

Q8. When the sea floods a glaciated valley, producing a long, deep inlet with steep walls, the feature is called a:

  1. Ria
  2. Fjord
  3. Lagoon
  4. Estuary
Show answer

Answer: B. Fjord

A fjord is a glacial trough that the sea has flooded. A ria is a river valley flooded by the sea, a lagoon is water cut off behind a bar or spit, and an estuary is a river mouth widened and scoured by tides.

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