Bottom relief Features MCQ Quiz - Objective Question with Answer for Bottom relief Features - Download Free PDF

Submarine Ridge.Key Points

• Mid-Oceanic Ridges or Submarine Ridges
  • A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. [Divergent Boundary]
  • The mountain ranges can have peaks as high as 2,500 m and some even reach above the ocean’s surface.
  • Running for a total length of 75,000 km, these ridges form the largest mountain systems on earth.
  • These ridges are either broad, like a plateau, gently sloping or in the form of steep-sided narrow mountains.
  • These oceanic ridge systems are of tectonic origin and provide evidence in support of the theory of Plate Tectonics.
  • Iceland, a part of the Mid-Atlantic Ridge, is an example.

Key Points

• Terrigenous deposits are derived from the land (statement I).
• The muds, which are the finest materials, are considered terrigenous deposits (statement III).
• The coloring of the muds is dependent on their chemical content (statement IV).
• However, statement II is incorrect because there is generally a decrease in the coarseness of terrigenous deposits from the shore onwards.

Additional Information

• Terrigenous Deposits:
  • Terrigenous deposits are sediments derived from the erosion of rocks on land.
  • These materials are transported to the ocean primarily by rivers, wind, and glaciers.
  • Examples include sand, silt, and clay.
• Continental Shelves:
  • The continental shelf is the extended perimeter of each continent, which is submerged under relatively shallow seas and gulfs.
  • It is typically rich in marine life and resources.
• Particle Size Distribution:
  • As sediments move away from the shore, there is a general trend of decreasing particle size.
  • Coarser materials like sand are deposited closer to the shore, while finer materials like silt and clay are carried farther out.
• Chemical Content of Muds:
  • The color of the muds can indicate their chemical composition. For example, red and brown muds often indicate the presence of iron oxides.
  • Black muds may indicate the presence of organic material or sulfide minerals.

The correct answer is Dolphin Rise.

Key Points

• The Mid-Atlantic Ocean is a submerged mountain range extending from Dolphin Rise to the north and Challenger Rise to the south.
• The Mid-Atlantic Ocean extends in 'S' shape.
• The mid-Atlantic ridge extended from Iceland in the north to Bouvet island in the south in 14,450 km length.

Additional Information

• The Mid-Atlantic ridge is known as Wyville Thompson Ridge between Iceland to Scotland. 
• The mid-Atlantic ridge is known as the Telegraphic plateau between the south of Greenland to Iceland.
• The mid-Atlantic ridge known as Challenger rises in the south of the equator.

The correct answer is 200 - 3000m.Key Points

• The continental slope connects the continental shelf and the ocean basins.
• It begins where the bottom of the continental shelf sharply drops off into a steep slope.
• The gradient of the slope region varies between 2-5°.
• The depth of the slope region varies between 200 and 3,000 m.
• The slope boundary indicates the end of the continents.
• Canyons and trenches are observed in this region.

Additional Information

• The ocean floors can be divided into four major divisions:
  • the Continental Shelf
  • the Continental Slope
  • the Deep Sea Plain
  • the Oceanic Deeps
• These divisions there are also major and minor relief features in the ocean floors like ridges, hills, sea mounts, guyots, trenches, canyons, etc.

The correct answer is Continental slope.

Key Points Ocean Floor Division can be divided into various parts such as Continental Shelf, Continental Slope, Continental Rise or Foot, Deep Ocean basins, Abyssal plains or Deep Sea plain, Oceanic Trenches, Seamounts, and Guyots.

Continental Slope

• The continental slope connects the continental shelf and the ocean basins. Hence, the correct answer is Continental slope.
• It begins where the bottom of the continental shelf sharply drops off into a steep slope.
• The gradient of the slope region varies between 2-5°.
• The depth of the slope region varies between 200 and 3,000 m.

Additional Information

Continental Shelf

• The continental shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs.
• It is the shallowest part of the ocean showing an average gradient of 1° or even less.
• The shelf typically ends at a very steep slope, called the shelf break.

Deep-Sea Plain or Abyssal plain

• These plains are gently sloping areas of the ocean basins.
• These are the flattest and smoothest regions of the world.
• It is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000m.
• Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface.

Oceanic Deeps or Trenches

• These areas are the deepest parts of the oceans.
• The trenches are relatively steep-sided, narrow basins.
• They are some 3-5 km deeper than the surrounding ocean floor.
• They occur at the bases of continental slopes and along island arcs and are associated with active volcanoes and strong earthquakes.

The correct answer is The US.

• The Grand Canyon is an example of a valley that is an erosional landform.
  • Erosion - It is the geological process in which earthen materials such as soil or rock are removed and transported by natural forces such as wind or water.
    • Valleys start as small and narrow rills.
    • The rills will gradually develop into long and wide Gullies.
      • A rill means a small stream.

​

• The gullies will further deepen, widen, and lengthen to give rise to valleys.
  • Gully - A small passage formed due to stream.

• Depending upon dimensions and shape, many types of valleys like V-shaped valleys, gorge, canyon, etc. can be recognised.
  • V-shaped valley 

• A canyon is characterised by steep steplike side slopes.
• A canyon is wider at its top than at its bottom. In fact, a canyon is a variant of a gorge.
• Valley types depend upon the type and structure of rocks in which they form.
  • Example - canyons commonly form in horizontal bedded sedimentary rocks and gorges form in hard rocks.
• The Grand Canyon :

• Gorge - A narrow valley with steep sides and a river running through it.

The correct answer is continental shelf.

Important Points

• The continental shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs.
• The Continental Shelf of all oceans together covers 7.5% of the total area of the oceans.
• The gradient of continental is 1° or even less.
• The continental shelves are covered with variable thicknesses of sediments brought down by rivers, glaciers, etc.
• Massive sedimentary deposits received over a long time by the continental shelves become the source of fossil fuels [Petroleum].
• Seaward extension of the continent from the shoreline to the continental edge approx. 200 m deep.
• In some places, where the coasts are extremely mountainous, such as in the Rocky Mountains, the continental shelf may be entirely absent.

 Additional Information

• Continental slope:
  • When seaward slope immediately becomes steep & gradient to about 1 in 20 with average depth 200 – 3000m.
  • Most of the canyons & trenches are observed in this region.
  • The continental slope connects the continental shelf and the ocean basins. ​
• ​Abyssal Plains:
  • The average depth is 3000 – 6000 m.
  • These plains are covered with fine-grained sediments like clay and silt.
• ​Oceanic Trench:
  •   They are some 3-5 km deeper than the surrounding ocean floor.
  • The trenches lie along the fringes of the deep-sea plain at the bases of continental slopes and along island arcs.
  • The trenches run parallel to the bordering fold mountains or the island chains.
• Deepest trench in the world → Marina trench (11 km) of Guam Islands (Pacific Ocean)   

The correct answer is Pacific Ocean.

Key Points

• The lithosphere is the solid, outer part of the Earth.
• The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure.
• It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.
• There are two types of lithosphere:
  • ​Oceanic lithosphere and continental lithosphere.
  • The Oceanic lithosphere is associated with oceanic crust and is slightly denser than the continental lithosphere.
• The Mariana Trench is the deepest part of the ocean and the deepest location on Earth about 11,035 meters (36,201 feet) deep.
  • The deepest point of Mariana Trench is Challenger Deep.
• It is located in the South Pacific Ocean and hence the maximum depth of Lithosphere is found in the Pacific Ocean.

Additional Information

• Siberian Plain:
  • West Siberian Plain is one of the world’s largest regions of continuous flatland situated in central Russia.
  • It occupies an area of nearly 1,200,000 square miles (3,000,000 square km) between the Ural Mountains in the west and the Yenisey River valley in the east.  
  • West Siberian Plain is bounded by the Kara Sea and in the south by the Torghay Plateau, the Kazakh Uplands (Saryarqa), and the Altai Mountains. 
• Patagonian Desert:
  • It is also known as the Patagonian Steppe and the largest desert in Argentina.
  • It is a mix of desert and semidesert that covers the Patagonian tableland that extends from the Andes to the Atlantic Ocean.
• Himalayan Mountains:
  • The Himalayas are geologically young and structurally fold mountains stretch over the northern borders of India.
  • These mountain ranges run in a west-east direction from the Indus to the Brahmaputra.
  • The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world.
  • They form an arc, which covers a distance of about 2,400 Km.
  • Their width varies from 400 Km in Kashmir to 150 Km in Arunachal Pradesh.

The correct answer is The Continental Deeps.

Key Points

• The ocean floors can be divided into four major divisions -
  • The Continental Shelf
  • The Continental Slope
  • The Deep Sea Plain
  • The Oceanic Deeps
• 
• Thus, 'the continental deeps' isn't one of them, making option 2 the right answer.

Additional Information

• A continental shelf is the edge of a continent that lies under the ocean.
• A continental slope is a slope seaward from the shelf to the upper edge of a continental rise or the point where there is a general reduction of the slope.
• A deep sea plain or an abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 meters and 6,000 meters.
• Oceanic deeps are the deepest parts of the oceans covered with fine-grained sediments like clay and silt.

Option 3 is not correct.

Key Points

Continental Shelf - It is the gently sloping seaward extension of the continental plate. It is the extended margin of each continent occupied by relatively shallow seas and gulfs.

• It is the shallowest part of the ocean.
• These are created due to sedimentation from the continents. Hence, statement 2 is correct.
• Continental Shelf is the gently sloping seaward extension of the continental plate. Hence, statement 3 is Not correct.
• The continental shelves are covered with variable thicknesses of sediments brought down by rivers, glaciers, etc.
• The shelves are almost absent or very narrow along some of the margins like the coasts of Chile, the west coast of Sumatra, etc. [Ocean – Continent Convergence and Ocean – Ocean Convergence]. Hence, statement 1 is correct.
• Continental shelves are located in photic zones, so have rich marine ecology. Hence, statement 4 is correct.
• The Continental Shelf of all oceans together covers 7.5% of the total area of the oceans.

The correct answer is Deep sea plains.

• Deep-sea plains are gently sloping areas of the ocean basins.

Additional Information

• Ocean Floor Division can be divided into various parts such as Continental Shelf, Continental Slope, Continental Rise or Foot, Deep Ocean basins, Abyssal plains or Deep Sea plain, Oceanic Trenches, Seamounts, and Guyots.
  • Deep-Sea Plain or Abyssal plain
    • These plains are gently sloping areas of the ocean basins.
    • These are the flattest and smoothest regions of the world.
    • It is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000m.
    • These plains are covered with fine-grained sediments like clay and silt.
    • Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface.
  • Oceanic Deeps or Trenches
    • These areas are the deepest parts of the oceans.
    • The trenches are relatively steep-sided, narrow basins.
    • They are some 3-5 km deeper than the surrounding ocean floor.
    • They occur at the bases of continental slopes and along island arcs and are associated with active volcanoes and strong earthquakes.
  • Continental Shelf
    • The continental shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs.
    • It is the shallowest part of the ocean showing an average gradient of 1° or even less.
    • The shelf typically ends at a very steep slope, called the shelf break.
  • Continental Slope
    • The continental slope connects the continental shelf and the ocean basins.
    • It begins where the bottom of the continental shelf sharply drops off into a steep slope.
    • The gradient of the slope region varies between 2-5°.
    • The depth of the slope region varies between 200 and 3,000 m.
    • The slope boundary indicates the end of the continents. 

The correct answer is Pacific Ocean. 

Key Points

• The Pacific Ocean got its name from the explorer Ferdinand Magellan. He called the ocean "mar pacific", which meant a peaceful sea. The Pacific Ocean is the largest and deepest ocean on Earth. The Pacific ocean covers more than 30% of the earth's surface.

Important facts about Mariana Trench:

• The Mariana Trench or Marianas Trench is located in the western Pacific Ocean
• It is located about 200 kilometres (124 mi) east of the Mariana Islands.
• 'Mariana Trench' is the deepest location on Earth.
• It is crescent-shaped and measures about 2,550 km (1,580 mi) in length and 69 km (43 mi) in width.
• The maximum known depth is 10,984 metres (36,037 ft), known as the Challenger Deep
• Some unrepeated measurements place the deepest portion at 11,034 metres (36,201 ft).
• The Mariana Trench is part of the Izu–Bonin–Mariana subduction system that forms the boundary between two tectonic plates.
• In this system, the western edge of one plate, the Pacific Plate, is subducted (i.e., thrust) beneath the smaller Mariana Plate that lies to the west.
• The United States has authority on Trench and its resources.

Hence, on the basis of the above facts, we can infer that the Mariana Trench is located in the Pacific Ocean.

The correct answer is Plain.

Key Points

• Physical features are things that humans can see all around and they would be here even if there were no humans around.
  • It comprises natural features like plains, seas, mountains and rivers.
• While, Ports, Road, Waterpark are features built by humans. 
• Mountains, hills, plateaus, and plains are the four major physical features.
• Minor features include buttes, canyons, valleys, and basins.
• The major Physiographic Divisions of India are the following:
  • The Himalayan Mountains
  • The Northern Plains
  • The Peninsular Plateau
  • The Indian Desert
  • The Coastal Plains
  • The Islands

The correct answer is Fossils.

About Radiocarbon Dating Technique:

• Radiocarbon Dating is used to estimate the Age of Fossils. The scientists combined Several Well Tested Techniques to find out the Ages and Compositions of Fossils. The method was developed at the University of Chicago by Willard Libby in the late 1940s.
• The most important techniques are Relative Dating, in which Fossils and Layers of rock are placed in order from Older to Younger ages, and in Radiometric Dating, which allows the actual ages of Certain Types of Rock to be calculated their ages.
• This technique helps in determining the Ages of an Ancient Fossil or Specimen by Measuring Fossils Carbon-14 content.
• Radiocarbon or Carbon-14 is a naturally occurring Radioactive Isotope that forms when Cosmic Rays in the upper atmosphere strike nitrogen (NO2) molecules, which then oxidize to become Carbon Dioxide.

Image of Working Process of Radiocarbon Dating Technique:

The correct answer is Lomonosov Ridge.Key Points

• The Lomonosov Ridge is an unusual underwater ridge of continental crust in the Arctic Ocean.
• It spans 1,800 kilometers between the New Siberian Islands over the central part of the ocean to Ellesmere Island of the Canadian Arctic Archipelago.
• The ridge divides the Arctic Basin into the Eurasian Basin and the Amerasian Basin.
• The width of the Lomonosov Ridge varies from 60 to 200 kilometers.
• It rises 3,300 to 3,700 meters above the 4,200-metre deep seabed.
• The minimum depth of the ocean above the ridge is less than 400 meters.
• Slopes of the ridge are relatively steep, broken up by canyons, and covered with layers of silt.
• The Lomonosov Ridge was first discovered by the Soviet high-latitude expeditions in 1948 and is named after Mikhail Lomonosov.
• The name was approved by the GEBCO Sub-Committee on Undersea Feature Names (SCUFN).

Additional Information