Kwong Oceans tbc

Question 1

How many oceans are there?

Answer 1

5:
Pacific
Atlantic
Arctic
Southern - Antarctic
Indian

Question 2

Deepest and largest ocean and deepest point?

Answer 2

Pacific
Mariana Trench
Challenger Deep
10900m
155.6 Mkm^2

Question 3

Smallest and shallowest ocean?

Answer 3

Arctic Ocean 1.2km mean depth, 14.1Mkm^2

Question 4

Percentage of Earth’s surface covered by oceans and seas?

Answer 4

71%

Question 5

Bathymetry layout pacific?

Answer 5

(From shelf out to sea)
Continent
Continental shelf
Continental slope
Continental rise
Abyssal plane + Seamount Guyots & Mid oceanic ridges on top
Trenches prevent sediment from covering abyssal plane surface

Question 6

Abyssal planes % of earth’s surface?

Answer 6

50%

Question 7

Vertical region of big Temperature change?

Answer 7

Thermocline
@500m upwards in the NE Pacific.

Question 8

Vertical region of big salinity change

Answer 8

Halocline
@700m upwards NE pacific

Question 9

Why do global sea temperatures change seasonally?

Answer 9

Sea ice gain and retreat

Question 10

What is NPP - net primary productivity?

Answer 10

Biomass/ carbon produced by primary producers (plants / algae etc) per unit area and time

Question 11

Spread of NPP in oceans?

Answer 11

20% (marine) coastal - 250g/cm^3/yr
80% (marine) deep ocean - 130g/cm^3/yr
10% (global) coastal
40% (global) deep ocean

Question 12

Reasons for spread of NPP?

Answer 12

High NPP - High Upwelling at equatorial regions
Lowest NPP mid latitudes with high Temperatures low pressures
Surface currents, South Pacific Gyre north along coast for example

Question 13

What areas have high NPP & upwelling?

Answer 13

West coast of Africa
East coast of South america
Nutrient dense surface waters with high levels of carbonates which promote high chlorophyll concentrations

River outputs and Ekmann increase NPP.

Question 14

Why are polar regions nutrient rich throughout?

Answer 14

“Intense mixing”
Shallow thermocline
Glacial melting influences nutrient density on the East coast of Greenland

Question 15

What is Ekman Transport?

Answer 15

Wind creates friction with the ocean surface
Ocean water moves at 90 degrees to wind due to rotation of the Earth/ Coriolis effect
10-100m of the water column moves up to replace displaced water or down to maintain mass conservation - this is Ekman pumping/ transport or suction.

Question 16

CS- Pelagic Deepwater Marine Ecosystem: Southern Ocean

Answer 16

Primary consumers bacteria, krill, zooplankton
Secondary consumers antarctic toothfish
Apex predators killer whales/ Sperm whales

Question 17

Ocean Carbon cycle

Answer 17

Phytoplankton / coccolithophores CaCO3 - lithification on sea floor
Carbon dissolved in mantle in sea floor spreading and subduction
Upwelling brings carbon rich waters to the surface
Downwelling cold water sinks
Carbonation - ocean water dissolves CO2 to form carbonic acid

Question 18

Biological pump

Answer 18

50 GT of carbon drawn from atmosphere each year

Question 19

How is ocean acidity measured?

Answer 19

NASA aquarius instrument aboard Argentina’s SAC-D satellite.
Measures microwave emissions of the top few cm of water
NASA SPURS project travelled to the North Atlantic’s saltiest spot to confirm Aquarius readings

Question 20

Cool ocean stats to be added to

Answer 20

86% of global evaporation and 78% of global precipitation happens over oceans.

Question 21

Antarctic food web stuff - how many krills?

Answer 21

85 species of krill in the Southern Ocean including the Antarctic Krill - very big - 5cm long - live to 5 years old
30,000 krill/ cubic metre
Krill migrate up and down each day to avoid being eaten
Krill faeces sink to the bottom sequestering 23 million tonnes of carbon a year