Continental rise is found after which part?
Correct answer: C
Continental rise forms below the slope due to sediment deposition. Exam tip: remember the order shelf, slope, rise.
Geography
Mapping of the ocean floor
महासागर तल का मानचित्रण
In this Class 11 Geography topic from “Distribution of Oceans and Continents,” students learn how the ocean floor is mapped and interpreted. They explore major features such as continental shelves, slopes, deep-sea plains, mid-ocean ridges, trenches and seamounts, and understand how soundings, sonar and bathymetric maps reveal underwater relief. The topic also helps connect ocean-floor patterns with plate boundaries, seafloor spreading and the changing distribution of continents and oceans.
TOPIC PRACTICE
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Easy · Level 4
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- Coastline
- Continental shelf
- Continental slope
- Mid-oceanic ridge
Easy · Level 4
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- They make the ocean colourless
- They stop clouds
- They are only food for fish
- They indicate floor structure and geological history
Easy · Level 4
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- Oceanic trenches
- Continental shelf
- Sea coast
- Lagoon
Easy · Level 4
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- To heat the ocean
- To make the map more accurate
- To reduce the number of ships
- To stop tides
Easy · Level 4
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- It stops all tsunamis
- It makes the ocean fresh
- It gives information about slopes, trenches and coastal depths
- It ends earthquakes
Easy · Level 4
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- Both are completely flat
- Both contain only sand
- Both have no relief features
- Both have features like mountains, plains and valleys
Easy · Level 4
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- By darker colour or greater depth value
- By tree symbols
- By road lines
- By population dots
Easy · Level 4
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- Oceanic trench
- Continental shelf
- Abyssal plain
- Mid-oceanic ridge
Easy · Level 4
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- Coastal plain
- River delta
- Seamount
- Desert sand
Easy · Level 4
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- Because all seas are very shallow
- Because oceans have no life
- Because divers do not read maps
- Because pressure and distance are very high in the deep sea
Easy · Level 4
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- To collect depth data using sonar instruments
- To carry tourists only
- To cause rainfall in the sea
- To colour fish
Easy · Level 4
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- It may show a spreading zone along the ridge
- It is only river erosion
- It is a city boundary
- It is a desert dune
Easy · Level 4
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- Oceanic trench
- Continental shelf
- Parliament House
- Abyssal plain
Easy · Level 4
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- It changes forests into oceans
- It immediately removes all pollution
- It tells the date of lunar eclipse
- It helps identify sensitive marine habitats
Easy · Level 4
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- Shape and slope of the floor
- Only sea breeze
- Only coastal language
- Only ship name
Easy · Level 4
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- It gives faster and more detailed measurements
- It closes the ocean
- It works only at night
- It does not measure depth
Easy · Level 4
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- Farmers
- Sailors and ship navigators
- Painters
- Poets
Easy · Level 4
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- Coastal lagoon
- River delta
- Mid-oceanic ridge
- Glacial lake
Easy · Level 4
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- It makes cables invisible
- It shuts down the internet
- It makes the ocean solid
- It helps select safe and low-risk routes
Easy · Level 4
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- Movement of plates
- Photosynthesis in plants
- Human census
- Language change
Easy · Level 4
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- Continental slope
- Abyssal plain
- Oceanic trench
- Seamount
Easy · Level 4
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- Only as a song
- Only as a story
- As maps, profiles and digital models
- Only as a poem
Easy · Level 4
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- Because only weather forms on the ocean floor
- Because there are no rocks in oceans
- Because all continents are fixed
- Because ridges, trenches and volcanoes show plate activity
Easy · Level 4
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- The sequence of depth and slope of the ocean floor
- Only the colour of the sea surface
- Only the taste of seawater
- Only the population of coastal cities
Easy · Level 4
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- The sea floor is very flat
- The sea floor slope is steep
- There is no depth in the sea
- The seawater is always fresh
Why are marine sediments important for understanding ocean floor mapping?
Correct answer: D
Sediments give information about sea-floor formation and history. Exam tip: remember sediments as oceanic records.
The deepest parts of the ocean floor are generally linked with which feature?
Correct answer: A
Oceanic trenches are among the deepest sea-floor features. Exam tip: link trenches with maximum depth.
Why is data collected repeatedly in ocean floor mapping?
Correct answer: B
More measurements reduce errors in depth and shape. Exam tip: connect repeated data collection with accuracy.
How can ocean floor mapping help in tsunami risk studies?
Correct answer: C
Relief and coastal depth help assess wave impact. Exam tip: connect mapping with disaster studies.
How is the shape of the ocean floor similar to the land surface?
Correct answer: D
The sea floor also has varied relief like land. Exam tip: understand the ocean floor as a hidden landscape.
How is a deeper area generally shown on a bathymetric map?
Correct answer: A
Bathymetric maps use colours and depth values to show depth. Exam tip: always read the map legend.
Which shallow and resource-rich part of the ocean floor is this?
Correct answer: B
The continental shelf is important for resources because it is shallow. Exam tip: link shelf with petroleum and fisheries.
An island of volcanic origin on the ocean floor can develop from what?
Correct answer: C
If a seamount rises above the surface, it may form an island. Exam tip: remember the seamount-volcano relation.
Why are technical instruments more necessary than direct diving in ocean floor mapping?
Correct answer: D
Human access is limited in the deep sea, so instruments are necessary. Exam tip: treat depth and pressure as major barriers.
What is the main role of a survey ship in ocean floor mapping?
Correct answer: A
Survey ships collect data related to depth and floor relief. Exam tip: understand survey ships as measurement platforms.
How can a long rift-like valley on the ocean floor be linked with a mid-oceanic ridge?
Correct answer: A
A rift zone on a mid-oceanic ridge may be linked with sea-floor spreading. Exam tip: remember rift and spreading together.
Which of the following is not an ocean floor feature?
Correct answer: C
Parliament House is a human-made structure, not an ocean floor feature. Exam tip: distinguish natural features from human-made objects.
How is ocean floor mapping useful in environmental studies?
Correct answer: D
Relief information helps understand marine habitats and conservation areas. Exam tip: connect mapping with conservation.
Along with depth, what else is understood in ocean floor mapping?
Correct answer: A
Mapping shows not only depth but also shape and slope of the floor. Exam tip: look at relief, not just numbers.
Why is sonar better than the old rope-and-weight method in ocean floor mapping?
Correct answer: A
Sonar gives faster and more accurate information than older methods. Exam tip: remember sonar as an example of technological progress.
For whom is depth information on marine maps most directly useful?
Correct answer: B
Sailors use marine maps to know safe routes and depths. Exam tip: connect marine charts with navigation.
A long mountain chain found on the ocean floor belongs to which category?
Correct answer: C
Mid-oceanic ridges are major raised features of the ocean floor. Exam tip: treat them as long submerged mountains.
How does ocean floor mapping help in laying submarine cables?
Correct answer: D
Cable routes are chosen by knowing slopes, trenches and obstacles. Exam tip: remember modern uses of mapping.
Mapping trenches and ridges on the ocean floor helps understand which natural process?
Correct answer: A
Trenches and ridges are related to plate movement and boundaries. Exam tip: study ocean features with plate tectonics.
Which is the broad and very extensive flat plain on the ocean floor?
Correct answer: B
An abyssal plain is a broad flat part of the deep sea. Exam tip: see it as flatter and less steep than a trench.
In what form can information obtained from ocean floor mapping be presented?
Correct answer: C
Depth data can be converted into maps, profiles and digital models. Exam tip: remember the process from data to map.
Why is understanding the ocean floor linked with Earth's internal processes?
Correct answer: D
Large sea-floor features are linked with Earth's internal movements. Exam tip: treat the ocean floor as evidence of a dynamic Earth.
What is understood from a cross profile of the ocean floor?
Correct answer: A
A cross profile shows the order of shelf, slope and deeper parts. Exam tip: treat a profile as a cut view of the ocean floor.
What is indicated when isobaths are close to each other?
Correct answer: B
Close isobaths mean depth changes quickly over a short distance. Exam tip: link close lines with steep slope.
QUIZ COMPLETE