Final

Question 1

What percentage of ocean water volume is affected by surface circulation?

Answer 1

10%

The remaining 90% is too deep to be affected by wind.

Question 2

What drives deep-water circulation in the ocean?

Answer 2

Density differences due to temperature and salinity

This is known as Thermohaline Circulation.

Question 3

What is Thermohaline Circulation?

Answer 3

Deep-water circulation driven by temperature and salinity differences

It involves heavier water sinking and lighter water rising.

Question 4

How long can a parcel of water keep its temperature and salinity characteristics after sinking?

Answer 4

1000 years or longer

Question 5

What percentage of ocean water has a narrow range of temperature and salinity characteristics?

Answer 5

75%

This is characterized by 0–5°C and 34–35‰.

Question 6

What are water masses?

Answer 6

Distinct packages of water with unique temperature and salinity combinations

They are named for their formation location and flow path.

Question 7

What is the Mediterranean Intermediate Water (MIW)?

Answer 7

A warm and salty water mass formed in the Mediterranean Sea

It flows through the ocean at an intermediate depth.

Question 8

What are the densest water masses and how are they formed?

Answer 8

Cold and salty water masses formed by freezing winds at high latitudes

Question 9

What is Antarctic Bottom Water (AABW)?

Answer 9

A dense water mass formed near Antarctica

It sinks into the deepest parts of the ocean.

Question 10

What role does CO2 content in deep water play in the Carbonate Compensation Depth (CCD)?

Answer 10

It determines how much CaCO3 is preserved as sediments on the ocean floor

Question 11

What happens to organic carbon in sediments with low O2 content?

Answer 11

It can convert to CH4 (methane gas)

Methane can act as a greenhouse gas if released.

Question 12

What is the effect of temperature on methane gas in sediments?

Answer 12

Cold temperature keeps methane frozen; warming can release it

Question 13

How long does it take for a water mass to make a round trip from the surface to the deep ocean and back?

Answer 13

1000–1500 years

Question 14

What is the significance of the deep ocean’s capacity to absorb heat and greenhouse gases?

Answer 14

It can act as a buffer to absorb excess heat and gases

Question 15

What are some chemical tracers used to track deep-water motion?

Answer 15

• Carbon-14 (14 C)
• Hydrogen-3 (3 H or tritium)
• Lead
• Chlorinated fluoro-carbons (CFCs)

Question 16

True or False: Deep-water currents move faster than surface currents.

Answer 16

False

Deep-water currents typically move at about 1 km/day compared to 2–5 knots for surface currents.

Question 17

Crest of a wave

Answer 17

The peak or highest point of a wave

Question 18

Trough of a wave

Answer 18

The lowest point of a wave

Question 19

Wave height

Answer 19

The difference in height between the crest and the trough

Question 20

Wavelength

Answer 20

The horizontal distance between two consecutive crests or troughs

Question 21

Wave period

Answer 21

The time interval between two crests (or two troughs) passing a fixed point

Question 22

Wave speed (celerity)

Answer 22

Calculated by dividing the wavelength by the wave period (meters per second)

Question 23

Factors affecting wave size

Answer 23

Stronger wind velocity

Question 24

Types of wind-generated waves

Answer 24

Seas (chaotic waves in a storm)

Question 25

Constructive interference

Answer 25

When two crests or two troughs coincide

Question 26

Destructive interference

Answer 26

When a crest coincides with a trough

Question 27

Wave motion in deep water

Answer 27

Water molecules move in circular orbits and do not interact with the sea bottom

Question 28

Wave motion in shallow water

Answer 28

Waves slow down

Question 29

Wave refraction

Answer 29

The bending of waves as they approach shallow water

Question 30

Tsunami causes

Answer 30

Sudden disturbances like earthquakes

Question 31

Tsunami speed in deep water

Answer 31

Can travel up to 500 mph (800 km/h)

Question 32

Storm surge

Answer 32

A mound of water pushed against the shore by a storm

Question 33

Internal waves

Answer 33

Underwater waves that move along density boundaries (pycnoclines) and travel more slowly than surface waves

Question 34

What causes most ocean waves?

Answer 34

Wind pushing the water surface into a wave form

Question 35

Three factors that affect wave size

Answer 35

Wind velocity

Question 36

What is a tsunami?

Answer 36

A wave caused by sudden seafloor movement due to earthquakes

Question 37

What happens to tsunamis near shore?

Answer 37

Wave height increases dramatically as water piles up behind the front of the wave

Question 38

How do tsunamis cause destruction?

Answer 38

Massive flooding and powerful wave energy destroying coastal areas

Question 39

What is wave interference?

Answer 39

When waves cross and pass each other

Question 40

What is constructive interference?

Answer 40

When two wave crests or two troughs coincide

Question 41

What is destructive interference?

Answer 41

When a crest coincides with a trough

Question 42

How do water molecules move in deep water waves?

Answer 42

Circular motion that does not interact with the sea bottom

Question 43

How do water molecules move in shallow water waves?

Answer 43

Elliptical motion as waves interact with the sea bottom

Question 44

What causes breaking waves?

Answer 44

Bottom friction slows waves down

Question 45

What is wave refraction?

Answer 45

The bending of waves as they approach a shoreline due to differences in speed

Question 46

How does wave refraction affect coastlines?

Answer 46

Waves focus energy on headlands (erosion) and spread out in bays (deposition)

Question 47

What is storm surge?

Answer 47

A large mound of water pushed onshore by strong storms

Question 48

What causes storm surge?

Answer 48

Low atmospheric pressure and strong winds driving water inland

Question 49

What is an internal wave?

Answer 49

An underwater wave that moves along density boundaries (pycnoclines) with large heights and slow speeds

Question 50

Why are tsunami warning systems important?

Answer 50

They help detect potential tsunamis and warn coastal populations to evacuate

Question 51

How can people recognize an incoming tsunami?

Answer 51

Rapid withdrawal of water from the shore or strong earthquake near the coast

Question 52

Why did the 2004 Indian Ocean tsunami cause so many deaths?

Answer 52

Lack of education and warning systems led people to walk onto the exposed seafloor before larger waves arrived

Question 53

How fast do tsunami waves travel in the deep ocean?

Answer 53

Up to 500 mph (800 km/h)

Question 54

What happens to a tsunami’s wavelength and height near shore?

Answer 54

Wavelength shortens and height increases dramatically

Question 55

What determines how a wave breaks?

Answer 55

The slope of the seafloor; gentle slopes cause spilling breakers