Oceanography TAMUCC Ch. 3 and 4

The mid-ocean ridge forms Earth's longest mountain chain, extending across approximately ________ miles of deep-ocean basin.

46,000

About how many years ago was the extinction of the dinosaurs?

66 million

What percent of volcanic activity takes place on the sea floor?

85

Where are the deepest portions of the world's oceans found?

At convergent plate boundaries

Which type of marine sediments include siliceous and calcareous oozes?

Biogenous

Passive margins are usually produced over geologic time by which of the following?

Continental rifting and continued sea floor spreading

The Indus River carries larger amounts of sediment from the ________ Mountains to the coast.

Himalayan

Marine phosphate is an example of which of the following sediment types?

Lithogenous Sediment

Where are the fewest abyssal plains located?

Pacific Ocean

Demand for which of the following resources has skyrocketed in recent years?

Rare-earth elements

Which of the following best describes turbidity currents?

Underwater avalanches of muddy water mixed with rocks and other debris

Sediments produced by plants and animals in the sea are called ________.

biogenous

Of the metals commonly found in manganese nodules, ________ is the only metal deemed "strategic" for the United States.

cobalt

Directly seaward of the continental shelf is a more steeply sloping region called the ________.

continental slope

A very important way to increase the settling rate of fine particles in the open ocean is via ________.

fecal pellets

Cosmogenous sediment consists of two main types of sediment ________.

microscopic spherules and macroscopic meteor debris

Sediments found on continental margins are called ________.

neritic

Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called ________.

oceanic rises

Sediment texture describes the ________ characteristics of a deposit.

physical

The correct order of seafloor features from the coast to the mid-ocean ridge is ________.

shelf, slope, rise, abyssal plain