Chapter 14 The Ocean Floor

Why is it uncommon to find calcareous ooze in deep-ocean basins?

Calcareous ooze is not found because these oozes are made up of calcium carbon shell and as the shells start moving inside a deep ocean they start dissolving. As they cross their limit that is approximately 15,000 feet in the deep ocean they completely dissolve and do not form any sediment.

What is a continental shelf? What economic significance do continental shelves have?

Continental shelves have the most important minerals deposits, including reservoirs of oil and natural gases.

From which area of the ocean basin are the recourses of oil and natural gas harvested?

Continental shelves of the ocean basin have huge economic importance and it contains recourses of oils and natural gas that can be harvested to use as the source of energy.

Approximately what percentage of Earth's Surface is covered by oceans? A: 40% B: 50% C: 60% D: 70%

D: 70%

Why is Earth called the "blue planet"?

Earth is commonly known as a blue planet because approximately 71% of the earth's surface covered by water.

Explain the process by which hydrogenous sediments are formed.

Mangenue nodules: They are hard, round limps of metals such as manganese, iron, and cobalt. Calcium carbonate: When ocean water precipitate in hot climates, it forms calcium carbonates.

In which ocean basin are most trenches found? Why?

Most of the trenches are found along the margin of the pacific ocean basin because they contain converging plates and mostly trenches formed at the site of plate convergence.

Why is multibeam sonar more efficient than simple sonar at collecting data from the ocean floor?

Multibeam sonar is more efficient than simple sonar since it uses multiple sound sources and listening devices. It can map a narrow swath of seafloor below the ship.

Compare and contrast deep-ocean trenches and mid-oceanic ridges.

When ocean crust formed a large interconnected system of submerged mountains commonly known as mid-ocean ridges. They are broad and cover one-half the total ocean floor area. Deep-ocean trenches and mid-ocean ridges have different sizes and shapes but both associated with the earthquake.

What could gas hydrates be used for? A: As landfill B: To make concrete C: As a source of energy D: As a source of cobalt and copper

A: As a source of energy

The gently sloping submerged surface that extends from the shoreline toward the ocean basin floor is the continental A: Shelf B: Slope C: Rise D: Margin

A: Shelf

Sediments that consists of minerals grains that were eroded from continental rocks are called A: Terrigenous B: Biogenies C: Hydrogenous D: Hydrates

A: Terrigenous

Important mineral deposits, including large reservoirs of oil and natural gas, are associated with A: The ocean basin floor B: The continental shelf C: Abyssal plains D: The continental rise

A: The ocean basin floor

Calcareous ooze is an example of A: terrigenous sediment B: biogenies sediment C: hydrogenous sediment D: a combination of hydrogenous and terrigenous sediment

B: Biogenies sediment

Submarine canyons are believed to have been created by A: Rivers during the ice age B: Earthquakes C: Lost ships D: Subduction

B: Earthquake

The use of sound waves to determine the depth of the ocean is called A: Submarine Sounding B: Sonar C: Satellite Altimetry D: Submersible Sounding

B: Sonar

Which ocean basin is the largest? A: The Atlantic B: The Pacific C: The Indian D: The Arctic

B: The Pacific

Economically valuable materials such as diamonds, tin, and platinum are associated with which ocean floor recourse? A: oil and natural gases B: sand and gravel C: evaporate D: manganese nodules

B: sand and gravel

What are the uses for sand and gravel harvested from the continental shelf?

Sand and gravel harvested from the ocean are used in landfilling, producing concrete, and filling in recreational beaches. Sometimes high economic value materials such as gold and diamonds are also found along with sand and gravels.

What is bathymetry? What techniques do scientists use to discover more about the bathymetry of ocean basins?

Scientists use sonar, submersibles, and satellites to find more information about bathymetry of the ocean. These technologies allow them to study the ocean floor in an efficient and precise manner.

What is the difference between terrigenous sediments and biogenies sediments?

Terrigenous sediment mainly consists of mineral grains, weathered from continental rocks. It contains large size particles. Biogenies sediment is mainly formed by the composition of skeletons and shells of dead marine organisms. It generally consists of small particles.

What current disadvantages exist to using gas hydrates as a form of energy?

The gas hydrates evaporate rapidly under normal surface pressure and temperature that is a major disadvantage of it as an energy source. However, in the future, these ocean-floor energy reserves might be able to help meet our energy needs.

Compare and contrast the size and topography of the Atlantic Ocean basin to that of the Pacific Ocean basin.

The topographical features of the Pacific Ocean basin contain continental slopes, abyssal plains, and volcanic seamounts. The topographical features of the Atlantic Ocean basin contain a submerged mountain range known as mid-ocean ridges.