Exam 13: The Ocean Floor

Earlier we discussed the concept of isostasy,where lower density rocks rise higher than higher density rocks.How is the variation of water depth at spreading centers (ridges)controlled by isostasy?

What is the difference between an active continental margin and a passive continental margin?

African dust from the Sahara desert is observed across the Atlantic as far west as the Caribbean region where it produces a hazy sky condition during the annual dry season.You are a climate scientist and make a prediction that the Sahara was not a desert during glacial periods in the northern hemisphere.How could you test this hypothesis by looking at deep sea sediments from the Atlantic off west Africa?

The continental rise is located ________.

Most of the world's landmass is in the northern hemisphere.

The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the ________.

Where are the deepest parts of the oceans?

Seafloor hot springs occur mainly in oceanic,abyssal plains.

Micro-organisms called foraminifera have tiny coiled shells with chambers,not unlike the chambering nautilus but much smaller.In modern oceans the coiling direction of foraminifera shells is correlated to temperature.Using coiling direction from foraminifera fossils is an example of ________.

Minerals that crystallize directly from seawater are examples of ________.

What type of continental margin is illustrated in the diagram below?

Examine Figure 13.B from Earth Science,14e below.Briefly explain the main points of Charles Darwin's hypothesis on coral atoll formation.Have we tested his hypothesis and is it still thought to be correct today? Can you think of another possible explanation that would explain the origin of such coral atolls?

________ continental margins typically exhibit wide,extensive,continental shelves.

Manganese nodules are an example of ________.

The crests of mid-oceanic ridges ________.

-calcareous ooze

Sand,silt,and clays deposited on the ocean floor are described as terrigenous sediments.

Which one of the following concerning mid-ocean ridges is false?

The oceans cover approximately ________ percent of Earth's surface.

A prominent feature of the Mid-Atlantic Ridge is a very deep linear valley known as a(n)________ valley.