Chemical
Proxy for phytoplankton measurement.
chlorophyll-a
Define geostrophic balance.
Geostrophic balance is the equilibrium between the Coriolis force and the pressure gradient force, leading to currents that flow parallel to sea surface height gradients
Zone where cold dense seawater infiltrates higher permeability regions of the oceanic crust
recharge zone
Marange
tidal range; vertical difference between high tide and seceding low tide
Explain how turbidity flows contribute to sedimentation in submarine canyons.
Turbidity flows, triggered by slope instability, transport sediments downslope, depositing them in fan-shaped patterns.
What are the units and orders of magnitude of dissolved oxygen?
surface ocean: 200-300 micromols/L
oxygen minimum zones: <10 micromols/L
anoxic zones: 0 micromols/L
*can also be measured in ml/L or % saturation
What forces control currents?
density
wind-forced circulation: friction of wind on sea surface drags water and creates motion
buoyancy-driven circulation: differences in density between equator and poles create pressure gradients that generate motion
Zone where high temp chemical interactions between water and rocks occur
reaction zone
Bedload deposition process
coarse sediments (like gravel) are transported along the seabed by rolling, sliding, or saltation and settle due to a reduction in transporting force
Describe the biological carbon pump and its significance in carbon cycling.
The biological carbon pump transfers CO₂ from the atmosphere to deep oceans via photosynthesis, food webs, and the sinking of organic matter, aiding long-term carbon storage.
What are the forms of nitrogen? Which is the most commonly used by phytoplankton?
nitrate (NO3), nitrite (NO2), and ammonium (NH4)
nitrate is most commonly used nitrogen source for phytoplankton
Describe the Coriolis effect.
How fluid deviates from its trajectory based on the rotation of the earth. Affects currents' direction.
In northern hemisphere, fluid deviates to the right of motion.
In southern hemisphere, fluid deviates to the left of motion.
zone where conductive and convective cooling (seawater mixing) allow for mineral precipitation
upflow/mineralization zone
Name some ways tides influence sediment deposition
bi-directional flow, heterolithic deposits, paired mud drapes, tidal bundles, tidal rhythmites, herringbone x-strat
Compare the effects of photosynthesis and respiration on DIC and alkalinity in seawater.
Photosynthesis decreases DIC without affecting alkalinity, while respiration increases DIC but also leaves alkalinity unchanged.
What is the third most common concentrated anion in the ocean?
HCO3, bicarbonate
What kind of motion are geostrophic balance, ekman transport, and tidal currents?
1.) geostrophic balance: slow and large scale motion
2.) ekman balance: windy conditions near surface
3.) tidal currents: fast and small-scale motion
What are the primary differences between lithogenous, biogenous, cosmogenous, and authigenic sediments?
Lithogenous sediments originate from weathered rock, biogenous from organic remains, cosmogenous from extraterrestrial material, and authigenic form in place through chemical processes.
Define the term "bedding plane" and its significance in stratigraphy.
A bedding plane is the smallest stratigraphic unit with a thickness over 1 cm, marking changes in sediment deposition.
What is the mixed layer in the ocean, and how does it deepen?
The mixed layer is the uniform upper layer of the ocean where turbulence driven by wind and convection mixes the water. It deepens when wind increases surface turbulence or when heat extraction causes colder, denser water to sink.
What are the nutrient orders of magnitude and units?
open ocean: 0.1-30 micromols/L
coastal/eutrophic zones: >50 micromols/L
also measured in mmol/m^3 and microM
Define amplitude, wavelength, height, and period.
amplitude: mid-point of wave to the top
wavelength: 1 peak to another peak
height: 2x amplitude (bottom to top)
period: from amplitude to amplitude
What is the carbonate compensation depth (CCD), and what factors influence it?
CCD is the depth at which carbonate dissolves faster than it accumulates, influenced by pressure, temperature, and ocean circulation.
What is the difference between estuaries and deltas?
estuaries: partly enclosed coastal body with one or more rivers/streams with free connection to the open ocean
deltas: sediment deposited where a river enters a body of water (estuaries can have deltas)
What is the Redfield Ratio, and why is it significant in nutrient cycling in the ocean?
The Redfield Ratio (16:1 nitrogen to phosphorus) represents the stoichiometric nutrient requirements of marine phytoplankton.