Quiz 1- global conveyor belt + abiotic factors

Question 1

State the four major abiotic factors that influence life in the ocean.

Answer 1

seawater temp
salinity
oxygen
light

Question 2

Identify the primary drivers of seawater temperature change

Answer 2

1) solar input (sun)
2) mixing of other water sources

Question 3

explain how solar input influences seawater temperature worldwide.

Answer 3

forms a temp gradient of surface water where equator has most access to sun and is the warmest

Question 4

explain how mixing of other water sources influences seawater temperature worldwide.

Answer 4

movement of warm surface waters down and cool deep waters up?

Question 5

Define salinity

Answer 5

the measure of dissolved inorganic solids in seawater
measured in ppt or psu (parts per thou or practical salinity units

Question 6

identify the major elements found in seawater

Answer 6

Cl and Na

Question 7

Explain why many elements in seawater are found at constant concentrations throughout the world’s oceans, and how we can use this to our advantage when calculating salinity.

Answer 7

• residence time (amount of time a substance spends in the water column before it settles- sediment, lost to the continents, etc.)
• The longer the residence time, the more constant you’ll find the concentration to be worldwide
• chlorine has the highest concentration in global oceans and a long residence time:
  ***SO we can use chlorinity measurement to estimate salinity

Question 8

Describe how oxygen concentration increases and decreases in the water column.

Answer 8

input thru the atmosphere and photosynthetic organisms
- further down, o2 removed and not being replaced (no photosynthesis or atmospheric replacement)- respiration (eg: fish)
- lower down: decomposition is completed by bacteria, algae, etc, which all also respirate

Question 9

Where is oxygen at its highest concentration, and why?

Answer 9

oxygen concentration is highest at the surface of the ocean BECAUSE this is where the water/air interface is AND because photosynthesizers live here bc of access to light

Question 10

Describe the vertical structure of oxygen concentration in the ocean, and the factor(s) that influence this structure.

Answer 10

• highest at surface
• drops dramatically at the thermocline- this is the oxygen minimum layer
• (a thermocline is an area where temp changes relatively drastically compared to what is directly above and below that level)
• slowly increases as depth increases- Below thermocline there is cold, O2 rich water from poles

Question 11

List the three major oceanic zones based on light.

Answer 11

• euphotic (sunlight) zone
• dysphotic (twilight) zone
• aphotic (midnight) zone

Question 12

euphotic (sunlight) zone

Answer 12

sunlight
photosynthetic organisms

Question 13

dysphotic (twilight) zone

Answer 13

NO photosynthesis
sunlight decreases rapidly with depth

Question 14

aphotic (midnight) zone

Answer 14

no sunlight whatsoever

Question 15

Hypothesize how the distance light travels through water might influence oxygen concentration.

Answer 15

photosynthetic organisms reside in areas that have access to sunlight

Question 16

Relate oxygen concentration, temperature and salinity in the ocean. How do they impact one another?

Answer 16

• temp and salinity influence density
• the colder, the more o2 can be held
• temp does not have a significant effect on salinity
• o2 conc and salinity do not have a significant relationship

Question 17

TRUE OR FALSE: Oceanic surface currents are influenced by planetary wind, while deep water currents are influenced by the Coriolis effect. FIX IF FALSE

Answer 17

FALSE:
- Oceanic surface currents are influenced by planetary wind and Earth’s rotation which together comprise the Coriolis effect.
- Deep water currents are mainly influenced by the sinking of cold and highly saline (dense) water near the poles

Question 18

TRUE OR FALSE: Deepwater currents are driven by the sinking of colder, higher salinity water at the poles. FIX IF FALSE

Answer 18

TRUE

Question 19

TRUE OR FALSE: Surface water currents are driven by upwelling, where deep water currents rise to the surface and push surface water out of the way. FIX IF FALSE

Answer 19

FALSE:
- Surface water currents are driven by planetary winds (which are affected by earth’s rotation, resulting in the Coriolis effect)
- Upwelling occurs when surface winds and planetary rotation at a coast lead to EKMAN TRANSPORT where the water moves 90 deg away from the coast and deep water moves in to replace it

Question 20

TRUE OR FALSE: Surface water currents only sink at lower latitudes where the water becomes more dense due to increased salinity. FIX IF FALSE

Answer 20

FALSE:
Surface water currents SOMETIMES sink at HIGHER latitudes where the water becomes more dense due to increased salinity (AS WELL AS COLDER TEMPERATURE)

Question 21

TRUE OR FALSE: Seawater density is impacted by temperature and salinity. FIX IF FALSE

Answer 21

TRUE

Question 22

TRUE OR FALSE: Differences in seawater density drive the restrictions in vertical circulation that lead to oxygen minimum layers between 200m-1200m deep in some parts of the ocean. FIX IF FALSE

Answer 22

TRUE

Question 23

TRUE OR FALSE: Seawater density is a primary driver of vertical circulation. FIX IF FALSE

Answer 23

TRUE

Question 24

TRUE OR FALSE: Density drives upwelling by forcing warmer surface water away from the coast, and bringing colder water to the surface. FIX IF FALSE

Answer 24

FALSE:
- density does not drive upwelling!!! its caused by the conditions that lead to ekman transport

Question 25

TRUE OR FALSE: Residence times explain salinity variation between the ocean and estuaries.

Answer 25

FALSE

Question 26

TRUE OR FALSE: Residence times explain constant proportions of major elements throughout the ocean.

Answer 26

TRUE

Question 27

TRUE OR FALSE: Residence times explain how river runoff impacts salinity in coastal environments.

Answer 27

FALSE

Question 28

TRUE OR FALSE: Residence times explain variations in salinity at different latitudes in the global ocean.

Answer 28

FALSE

Question 29

Define Global Conveyor Belt Circulation.

Answer 29

global conveyor belt circulation connects surface and deep ocean

Question 30

Describe the Coriolis Effect and how it influences ocean surface waters. How does its influence differ in the southern hemisphere vs northern hemisphere?

Answer 30

Coriolis Effect- a deflection in surface current direction
- northern hemi: clockwise
- southern hemi: counter-clockwise

Question 31

Explain the role Gyres and Boundary Currents have in the transport of ocean water, nutrients and (potentially even) living organisms.

Answer 31

gyres move clockwise in the Northern Hemisphere and counterclockwise in the southern hemisphere- large-scale transport of surface water from the tropics to higher latitudes
OBCs- western side of Atlantic + pacific gyres (eg: gulf stream)- very FAST and transport LARGE volumes of water- warm core and cold core rings break off (aka eddies)
eddies can transport water, nutrients, and sometimes even animals to places they may not typically be found

Question 32

Define Ekman Transport and describe how this process works to influence coastal upwelling and downwelling.

Answer 32

the NET movement of water resulting from wind + coriolis effect (leads to water moving 90 deg either towards or away from shore line)
- Wind moves the water in the direction it’s moving- layers of water under the top move in the same direction but more and more slowly than at the top because it’s being pulled less by the wind
- coastal upwelling and downwelling depending on which way the wind blows (eg: northern hemi- wind is blowing north along the Peruvian coast, and the coriolis effect is making the water blow 90 deg clockwise (left) away from the coast and upwelling happens as deeper water replaces the surface water)

Question 33

Compare and contrast the drivers of horizontal and vertical water movement in the ocean.

Answer 33

horizontal- wind and coriolis effect
vertical- changes in seawater density

Question 34

Identify the major characteristics used to define water masses in the ocean.

Answer 34

temp
salinity
other physio-chemical characteristics

Question 35

Define thermohaline circulation and describe the role it plays in the global conveyor belt system.

Answer 35

Thermohalinity = density (combination of temp and salinity)
Thermohaline circulation- how density drives vertical water movement

Question 36

Understand how density relates to temperature and salinity, and the role this relationship plays in thermohaline circulation.

Answer 36

Colder + saltier = denser
warmer + less salty = less dense
O2 rich surface water gets colder as it moves away from equator and grabs more o2 bc cold water can hold higher O2 concentration, gets more saline as well (collects salt that has left the water that froze at the poles) and becomes dense (bc it’s cold + salty) and sinks to the bottom

Question 37

Explain how the world’s surface waters and deep ocean are connected through the global conveyor belt, and give examples of why this is important to consider when studying marine organisms.

Answer 37

surface water at the poles sinks and moves O2 to the bottom of the ocean but ALSO nutrients and CO2 and other stuff!
deep water gets brought up, usually by ekman transport, bringing nutrients from the bottom back up