Matthieu
Describe coastal zones in terms of fluvial and mixing mechanisms
water enters system via rain and rivers, leaves via evaporation
river discharge: strong salinity gradients, high nutrients
tides increase vertical & horizontal mixing so nutrients and DO are dispersed throughout water column.
True or false: Increased carbon dioxide makes alkalinity and pH decrease.
False: CO2 DOES NOT CHANGE ALKALINITY
Name the three drivers of sea water density
temperature, pressure, salinity
Describe tectonic plate movements
1.) divergent processes-- plates separating, forms ridges
2.) convergent processes-- plates coming together, subduction
Define a hypoxic zone and give an example.
Hypoxic: low dissolved oxygen
Baltic sea: always stratified due to salinity; intense halocline (deep salty waters) prevents oxygen from mixing between surface and deep; excess nutrients from fluvial inputs fuel blooms that use up all the surface oxygen
What are the orders of magnitude for salinity (include units)?
open ocean: 32-37 PSU
estuaries: 0.5-30 PSU
hypersaline environments: >40 PSU
Where are the highest particulate organic carbon fluxes located? The lowest?
upwelling & oligotrophic (low nutrient) gyres
Explain the different relationships between ocean temperature and air temperature.
1.) local radiative force: the closer to the equator, the more heat the surface receives from the sun
2.) latent heat fluxes: (evaporation/condensation), depends mostly on wind speed and air humidity
3.) sensible heat fluxes: air-sea temperature exchange (depends mostly on air temperature)
4.) long wave radiative fluxes: ocean radiates heat to atmosphere and space (depends mostly on SST)
Name the parts of the continental margin (and describe them if you can)
1.) continental shelf: submerged extension of the continent, gently sloping seabed stretching from shoreline to the shelf break
2.) continental slope: transition from continental shelf to the deep ocean floor, steep gradient
3.) continental rise: gently sloping region found at bottom of slope, formed by accumulation of sediments
4.) abyssal plain
5.) submarine canyons: steep-sided v-shaped valleys extending from the continental shelf and slope, often extending from river mouths
What is one of the bonus equations Thomas asked us to know?
m.a = sum of Fi (both a and Fi have arrows on top)
a = dv/dt (a and v have arrows on top)
Describe the thermocline, halocline, and pycnocline
thermocline: temperature changes rapidly with depth, separating warmer surface waters with cold deep water
halocline: salinity changes sharply with depth (salty bottoms), often found in areas where freshwater and saltwater mix (estuaries)
pycnocline: density increases with depth typically due to combined changes in temp and salinity (cold & salty bottoms = more dense)
Describe the relationship between carbon species (CO2, bicarbonate, and carbonate) and pH.
high CO2 = low pH (highly acidic)
high bicarbonate = neutral pH, low CO2 and low carbonate
high carbonate = high pH (basic)
In the Southern hemisphere, which direction does water deviate from its trajectory?
Left
Similarities of hydrothermal vents and cold seeps
1.) fluid fluxes: both are releasing fluids of reduced CCH4 and metals from beneath the seafloor
2.) chemosynthetic ecosystems: microbes oxidize chemicals like methane or hydrogen sulphide to produce energy -- forms base of food chain
3.) unique adaptations: both host highly specialized organisms relying on symbiotic bacteria for nutrition
4.) biodiversity hotspots: considered biodiversity hotspots in the deep sea, providing habitat and food for a wide range of marine species
Describe the Ekman balance.
A current takes the form of a spiral and the mean current is perpendicular to the wind's direction. A north wind will have an eastward Ekman transport; a west wind will have a southward Ekman transport.
Discuss temporal distributions of nutrients within the Bay of Brest.
1.) winter: pp limited by light, high precip
2.) spring: biggest fluvial inputs (snow melt), 1st blooms occur as light increases, less nutrients due to less rain and tidal mixing
3.) summer: pp limited by nutrient availability (silicic acid first then nitrate)
4.) fall: smaller blooms, increase in nutrients & light limitations
Refer to Figure 5. How do you interpret these reactions?
All are forms of rock weathering/erosion and all produce bicarbonate (2HCO3). Bicarbonate affects DIC and Alkalinity.
What is the Navier Stokes equation?
acceleration = coriolis force + pressure force + viscous force
Name the sediment deposition processes
oscillatory flow (waves), unidirectional flow (currents), gravity movement (slope failure, turbidity current), suspension in water column, wind
Serpentinization
What are the orders of magnitude for particulate organic matter (POM)? Include units.
open ocean: 0.1-1 mg/L
coastal waters: 1-10 mg/L
*higher in coastal bc of increased productivity and runoff
Look exercise 1. How would you calculate the units of CO2 needed to be removed to restore equilibrium (current state is oversaturated)?
Multiply the amount precipitated by the theoretical coefficient (will be given on the exam).
*we may need to know how to calculate the amt precipitated though
50 micromols/kg * 0.63 = 32 micromols/kg
In which direction does a current flow with a northward wind?
What are the three types of deltas?
1.) wave-influenced: river sediments can be heavily redistributed/reworked, creates swash bars
2.) tidal-influenced: river sediment creates tidal bars
3.) fluvial dominated: if waves/tides are weak, coarse sediment is deposited at mouth of river and creates mouth bars
Name and describe the components of the Nitrogen cycle. (Hint: there are 6)
1.) nitrogen fixation: fixated into some sort of organism
2.) ammonium/ammonia: being transformed into R-NH3 (prob a protein, organic based)
3.) ammonia oxidation: oxygen added
4.) nitrification: adding more nitrogen relative to the hydrogen
5.) nitrogen oxidation: losing energy
6.) denitrification: losing more oxygen, gaining more nitrogen