What Are Continental Margins


What is a continental margin?

continental margin the submarine edge of the continental crust distinguished by relatively light and isostatically high-floating material in comparison with the adjacent oceanic crust. It is the name for the collective area that encompasses the continental shelf continental slope and continental rise.

What is the continental margin and what are its parts?

The continental margins consist of three portions: (1) the continental shelf which has shallow water depths rarely deeper than 650 ft) and extends seaward from the shoreline to distances ranging from 12.3 miles to 249 miles (2) the continental slope where the bottom drops off to depths of up to 3.1 miles and (3) the …

What is the continental margin quizlet?

continental margin. refers to the edge of the continent and includes the area from the true continental interior seaward to the deep ocean floor. coastal plain.

What is the continental margin part of?

The continental margin is that part of the ocean floor at the edges of the continents and major islands where just beyond the shoreline it tapers gently into the deep sea. The continental margin is made up of the continental shelf the continental slope and the continental rise.

What are main features of continental margins?

The continental margin consists of three different features: the continental rise the continental slope and the continental shelf. Continental margins constitute about 28% of the oceanic area.

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Where are continental margins found?

An active continental margin is found on the leading edge of the continent where it is crashing into an oceanic plate. An excellent example is the west coast of South America. Active margins are commonly the sites of tectonic activity: earthquakes volcanoes mountain building and the formation of new igneous rock.

How are active continental margins formed?

Active margins are commonly the sites of tectonic activity: earthquakes volcanoes mountain building and the formation of new igneous rock. These are often marked by uplift and volcanic mountain belts on the continental plate and by island-arc chains on the oceanic plate.

What is continental margin Class 11?

Answer: The continental margin is the extended portion 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.

Which is not part of the continental margin?

Which of the following is NOT part of the continental margin? coral reefs surrounding a lagoon. You just studied 65 terms!

Which is the largest continental shelf?

the Siberian Shelf

Notes: The largest continental shelf is the Siberian Shelf in the Arctic Ocean.

What are continental shelves quizlet?

continental shelf. the sloping shelf of land consisting of the edges of the continents under the ocean.

What does continental slope mean in science?

A continental slope is defined by the IHO as “the slope seaward from the shelf to the upper edge of a continental rise or the point where there is a general reduction of slope.

Which is closest to the continental margin?

continental shelf

The part of the continental margin closest to land is called the continental shelf. The continental shelf is the flat shallow sloping area we are…

How does a continental margin differ from a deep ocean basin?

Continental margins – these are regions that extend from the coast across shallow shelf regions to the edge of continents where the seafloor descends into deep water. Deep-ocean basins – This includes parts of the oceans where deep water prevails. Deep ocean basins cover the greatest portion of the Earth’s surface.

What is an example of a place residing on a continental margin?

Active continental margins

Examples include the Andes Mountains along the western coast of South America. Coasts along active margins are typically lifted upward by the subduction of the oceanic plate forming terraces and cliffs that are eroded by the ocean’s waves.

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What is a continental feature?

continental landform any conspicuous topographic feature on the largest land areas of the Earth. Familiar examples are mountains (including volcanic cones) plateaus and valleys.

What are passive continental margins?

A passive margin is the transition between oceanic and continental lithosphere that is not an active plate margin. A passive margin forms by sedimentation above an ancient rift now marked by transitional lithosphere. Continental rifting creates new ocean basins.

What is the continental rise made of?

A continental rise consists mainly of silts mud and sand deposited by turbidity flows and can extend for several hundreds of miles away from continental margins. Although it usually has a smooth surface it is sometimes crosscut by submarine canyons extending seaward of continental slope regions.

What marks the true division between continents and oceans?

​Continental crust is less dense than oceanic crust. ​What marks the true division between continents and oceans? … ​The average ocean depth is greater than the average elevation of continents.

Where is the most biologically rich part of the ocean?

continental shelf
The continental shelf is the shallowest part of the continental margin. Although they only make up 8% of the Earth’s ocean surface area they are the most biologically rich part of the ocean containing the majority of the sea life.

What is the steepest part of the continental margin?

continental slope
After the shelf break the seafloor takes on a steeper angle (about 4o) as it descends to the deep ocean. This steeper portion of the margin is the continental slope and it extends from the shelf break down to 3000-5000m.

What do active continental margins have?

Active margins are marked by earthquakes volcanoes and mountain belts. Unlike passive margins they lack a continental rise and abyssal plain. Instead the continental slope ends in an oceanic trench and beyond the trench the topography is hilly and irregular often dotted with rugged volcanic seamounts.

What do passive and active continental margins have in common?

Volcanoes and earthquakes are common at active margins. Active margins are near plate boundaries. Passive margins are passive. They have little or no geological activity.

What region of a continental margin blends into the deep ocean basin?

Both active and passive margins have three divisions: A shallow nearly flat continental shelf close to shore. A more steeply sloped continental slope to seaward. And the continental rise an apron of sediment that blends the continental margins into the deep ocean basins.

How are tides caused Class 11?

Tides are caused by: The moon’s gravitational pull to a great extent. The sun’s gravitational pull to some extent are the major causes for the occurrence of tides. Another factor is centrifugal force which is the force that acts to counter balance the gravity.

Which ocean is saltiest?

the Atlantic Ocean
Of the five ocean basins the Atlantic Ocean is the saltiest. On average there is a distinct decrease of salinity near the equator and at both poles although for different reasons.

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Which is the largest and deepest ocean in the world?

The Pacific Ocean
The Pacific Ocean is the largest and deepest of the world ocean basins. Covering approximately 63 million square miles and containing more than half of the free water on Earth the Pacific is by far the largest of the world’s ocean basins. All of the world’s continents could fit into the Pacific basin.Feb 26 2021

Are mid ocean ridges?

Mid-ocean ridges occur along divergent plate boundaries where new ocean floor is created as the Earth’s tectonic plates spread apart. … Two well-studied mid-ocean ridges within the global system are the Mid-Atlantic Ridge and the East Pacific Rise.

Which portion of the continental margin would you find submarine canyons?

Unlike deep-sea trenches which are found in areas where one tectonic plate slides beneath another undersea canyons are found along the slopes of most continental margins. They also occur along the slopes of the Hawaiian Islands and possibly certain other ocean islands.

Which type of crust typically comprises the continental margin?

Which type of crust typically comprises the continental origin? Continental crust is mostly granite a coarse-grained igneous rock and oceanic crust is mostly basalt a fine-grained igneous rock.

How deep is the continental slope?

The world’s combined continental slope has a total length of approximately 300 000 km (200 000 miles) and descends at an average angle in excess of 4° from the shelf break at the edge of the continental shelf to the beginning of the ocean basins at depths of 100 to 3 200 metres (330 to 10 500 feet).

How far is continental shelf?

200 nautical miles
According to the UN Convention on the Law of the Sea every nation has a continental shelf extending no more than 200 nautical miles from the nation’s coastline.Mar 4 2011

Why are continental shelves important?

The significance of the continental shelf is that it may contain valuable minerals and shellfish. UNCLOS addresses the issue of jurisdiction over these resources by allocating sovereign rights to the coastal State for exploration and exploitation.

How can you best describe the continental shelf?

continental shelf a broad relatively shallow submarine terrace of continental crust forming the edge of a continental landmass. The geology of continental shelves is often similar to that of the adjacent exposed portion of the continent and most shelves have a gently rolling topography called ridge and swale.

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