Question 2 of 21

The oceans cover ______ of the Earth's surface.

... The “seven seas” take up 70 percent of the Earth's surface and include 97 percent of the world's water.

Question 3 of 21

Which ocean is the largest?

... The Pacific ocean, which includes the North and South Pacific subdivisions, is the largest ocean. The Pacific ocean is 181 million square kilometers.

Question 4 of 21

Which ocean basin is the most geologically active?

... The Pacific ocean contains many volcanic vents, seamounts and deep trenches. The Pacific basin is a rocky floor.

Question 5 of 21

How does water move around the world?

... Shallow water is driven by wind, whereas deep water is driven by gravity.

Question 6 of 21

Ocean water moves:

... Ocean water moves in large circular patterns called gyres. The Gulf Stream, which moves from Florida to the North Atlantic Ocean, is an example of a gyre.

Question 7 of 21

What are thermohaline currents?

... Thermohaline currents move from the surface of the water down to the ocean floor and back.

Question 8 of 21

What type of water is more dense?

... Polar water is more dense because molecules travel closer together and because of salt crystals in the water.

Question 9 of 21

What are basalts?

... When plates on the ocean floor move apart, magma oozes out. This magma cools and hardens forming rocks, known as basalts, on the ocean floor.

Question 10 of 21

What are the abyssal plains?

... A large part of the ocean floor is flat and made up of sediment. These areas are known as the abyssal plains.

Question 11 of 21

What property of water does salt alter?

... Salt in water alters its freezing point. Deep ocean water can still remain liquid at -2 degree Celsius.

Question 12 of 21

What are the main categories of sea life?

... Sea life consists of plankton (floaters), nekton (swimmers) and benthos (creatures on the sea floor).

Question 13 of 21

What are phytoplankton?

... Phytoplankton are microscopic algae that engage in photosynthesis.

Question 14 of 21

What are zooplankton?

... Zooplankton eat phytoplankton. Small worms, small jellyfish, clams and larvae are examples of zooplankton.

Question 15 of 21

What are examples of benthos?

... Lobsters, oysters, sea anemones, barnacles, snails and halibut are all examples of benthos. These creatures all live along the ocean floor.

Question 16 of 21

What type of creatures live near hydrothermal vents in the deep sea?

... The deep sea is the equivalent of a barren desert. Not much lives in the deep sea. Close to hydrothermal vents, however, you can find clams and worms.

Question 17 of 21

What sea life is at the very bottom of the food chain?

... Phytoplankton, which produces carbohydrates, is at the very bottom of the food chain. Phytoplankton is consumed by plankton.

Question 18 of 21

What do sea sponges eat?

... Sponges just sit and wait at the bottom of the sea. They feed on dead-organisms and small food particles from fish higher above.

Question 19 of 21

What sea creature may have cancer-fighting properties?

... Researchers are investigating the cancer fighting properties of the ocean sponge and the sea-squirt.

Question 20 of 21

Seaweed compounds are added to:

... The Japanese eat more than 20 different varieties of seaweed. American use seaweed in abundance as well. Seaweed compounds are added to beer, ice cream and salad dressing.

Question 21 of 21

Where does offshore oil drilling occur?

... The ocean's bounty also includes non-living products. Extensive offshore drilling occurs in the Persian Gulf, the North Sea and the Gulf of Mexico.