Earth Science Test 2

What do submersibles do?

1. collect data that humans can't reach 2. remain underwater for a long time

What is the pseed of sound in water?

1500 meters per second

How much methane may be locked up in sediments containing gas hydrates?

20 quadrillion cubic meters

Approximately when did the ocean become an important area of study?

200 years ago

Approimately how much of Earth's surface is covered by land?

30%

How much of the world's oil production currently comes from offshore regions?

30%

Approximately how much of Earth's surface is covered by water?

70%

Which submersible has been used for deep-sea research?

Alvin

Which of the following is NOT considered one of the four major oceans? Atlantic, Pacific, Indian, Antarctic

Antarctic

The largest of Earth's oceans c0is the _________.

Atlantic

Most gas hydrates form when what occurs?

Bacteria breaks down organic matter trapped in ocean-floor sediments

Which of the following is NOT trued about deep ocean trenches? a. They are long narrow depressions. b. They are sites where plates plunge back into the mantle. c. They are geologically very stable. d. They form the deepest parts of the ocean.

C. They are geologically very stable.

Which ocean has the greatest average depth?

Pacific

What is oene disadvantage of using gas hydrate?

They rapidly break down at surface temperatures nad pressures.

Which ofhte following is NOT a biogenous sediment? a. manganese nodules b. calcareous ooze c. siliceous ooze d. phosphate-rich material

a. manganese nodules

Which region are thought to be the most level places on Earth?

abyssal plains

Where does seafloor spreading occur?

at divergent plates

which of the following is associated with mid-ocean ridges? a. rift valleys b. mountainous topography c. extreme temperatures d. volcanic structures

b. mountainous topography

Clacareous ooze is an example of ___________.

biogenous sediment

Which of the following is NOT one of the three major regions on the ocean floor? a. continental margins b. ocean basin floor c. coastal plain d. mid-ocean ridges

c. coastal plains

Which ofhte following is not a zone included in the continental margin? a. continental slope b. continental rise c. continental coast d. continental shelf

c. continental coast

Which of the following currents is associated with downslope movements of dense sediment-rich water? a. avalanche current b. density current c. turbidity current d. longshore current

c. turbidity current

The gently sloping submerged surface extending form the shoreline toward the deep ocean is called___________.

continental shelf

Important mineral deposits, including large reservoirs of oil and natural gas, are associated with ___________.

continental shelves

Which of the following occurs at the continental margin in the Pacific Ocean? a. volcanic activity b. earthquakes c. plate interactions d. all of the aboe

d. all of the above

Which of the following is NOT a hydrogenous sediment? a. manganese nodules b. calcium caronates c. evaporates d. calcareous ooze

d. calcareous ooze

Manganese nodules are an example of ____________.

hydrogenous sediment

What type of sediment forms from minerals that crystalize from seawater?

hydrogenous sediment

Mineral-rich water, heated by newly formed oceanic crust, escapes through cracks in the ocean floor called ____________.

hydrothermal vents

Which ocean resource is currently NOT economically profitable to mine?

manganese noodules

The Persian Gulf, the Gulf of Mexico, and the North Sea are all known for their reserves of what ocean resource?

oil

Heat form Earth's interior and pressure form overlying rock rransform the remains of marnie sediments into _________.

oil and natural gas

Where trenches do not exist, the steep continental slope merges into a more gradual incline known as the continental _______________.

rise

Which ocean resources are second in economic value to oil?

sand and gravel

Differences in ocean-surface height can be measured by ____________.

satellites

Isolated volcanic peaks on the ocean floor are called __________.

seamounts

Biogenous sediment si mad eup of ___________.

sehlls and skeletons of marine organisms

Which type of sediment is made up of mainly of the shells fo diatoms and radiolarians?

siliceous ooze

Which ofhte following is NOT an ocean resource? a. sand b. common table salt c. natural gas d. silver

silver

What technology do scientists use to measure ocean depth?

sonar

Deep, steep-sided valleys that originate on the continental slope and may extend to the ocean basin floor are called __________.

submarine canyons

Sediments derived primarily from the products of weathering on the continents are calld ____________.

terrigenous sediment

When seawater evaporates, the concentration fo salts increases until what occurs?

the salts precipitate out of the solution

Which part ofhte ocean is the deepest?

trenches

Seamounts are _________________.

volcanoes that form on the ocean floor