Oceanography Practice 1

Technology called (a)   uses sound waves to determine the depth of the ocean floor.

• sonar

• radar

• laser

• infrared

Answer explanation

The correct answer is sonar, which uses sound waves to measure distances underwater, including the depth of the ocean floor. Radar, laser, and infrared do not operate effectively in water for this purpose.

Tags

NGSS.MS-PS4-2

The (a)   is a smooth, nearly flat region of ocean floor covered with layers of mud and silt.

• abyssal plain

• continental shelf

• mid-ocean ridge

• trench

Answer explanation

The abyssal plain is a smooth, nearly flat region of the ocean floor, typically covered with layers of mud and silt. This distinguishes it from other options like the continental shelf, mid-ocean ridge, and trench.

Beyond the edge of the continental shelf lies the (a)   zone, which is the deepest and darkest area of the ocean.

• oceanic

• abyssal

• pelagic

• benthic

Answer explanation

The correct answer is 'oceanic' as it refers to the vast body of water beyond the continental shelf, which includes the abyssal zone, the deepest and darkest part of the ocean.

Most waves form when energy is transferred to water from (a)   .

• wind

• sun

• earthquake

• rain

Answer explanation

Waves primarily form when energy is transferred to water from the wind. The movement of air over the surface of the water creates ripples and larger waves, making wind the correct answer.

As a wave nears shore, the (a)   decreases and the wave height increases.

• wavelength

• speed

• frequency

• amplitude

Answer explanation

As a wave approaches the shore, the water becomes shallower, causing the wavelength to decrease. This reduction in wavelength results in an increase in wave height, making 'wavelength' the correct answer.

Tsunamis are caused by (a)   on the ocean floor.

• earthquakes

• volcanoes

• hurricanes

• tornadoes

Answer explanation

Tsunamis are primarily caused by earthquakes occurring on the ocean floor, which displace large volumes of water. While volcanoes can also trigger tsunamis, the most common cause is earthquakes.

Tags

NGSS.MS-ESS3-2

Hills of wind-blown sand called (a)   help to prevent beach erosion.

• dunes

• mountains

• valleys

• plains

Answer explanation

Dunes are hills of wind-blown sand that form along beaches and help to stabilize the shoreline, preventing beach erosion. Other options like mountains, valleys, and plains do not serve this specific function.

A wall of rocks or concrete built outward from a beach is called a(an) (a)   .

• groin

• jetty

• pier

• breakwater

Answer explanation

A groin is a structure built outward from a beach to prevent erosion and control sediment. Unlike jetties and piers, which serve different purposes, a groin specifically aims to protect the shoreline.

Evaporation increases the salinity of sea water, since the salt is left behind as the water evaporates.

(a)  

• salinity

• temperature

• density

• pressure

Answer explanation

Evaporation causes water to leave, but the salt remains, leading to an increase in salinity. Therefore, the correct answer is salinity, as it directly relates to the concentration of salt in sea water.

Algae in the ocean carry out photosynthesis and release the gas (a)   into the water.

• oxygen

• carbon dioxide

• nitrogen

• hydrogen

Answer explanation

Algae perform photosynthesis, a process that converts carbon dioxide and sunlight into energy, releasing oxygen as a byproduct. Therefore, the correct gas released into the water is oxygen.

Tags

NGSS.MS-LS1-6