MAST 637 Practice Exam 2

What are IRD

Ice Rafter Debris

Flocculation

the natural process where fine-grained suspended particles-such as clay, slit, and organic matter-collide and bind together to form larger, porous, and fragile aggregates known as flocs

Estuarine

partially enclosed coastal body of brackish water where freshwater from rivers and streams meets and mixes with saltwater from the ocean

Flocculation is an important mechanism to scavenge elements in what setting

Estuarine - flocculation occurs when fresh water meets slaty seawater, causing clay particles to clump together

Seawater is what with respect to biogenic silica

under saturated - almost all seawater is undersaturated with respect to silica, which is why diatom shells dissolve as they sink

NADW

North Atlantic Deep Water

AABW

Antarctic Bottom Water

NADW and AABW are types of what

Water masses that from at high latitudes

what and what are primary control of deep ocean circulation

Temperature and Salinity

Halocline

Rapid change in salinity

Thermocline

Rapid change in temperature

Pycnocline

Rapid change in density

The range of depth at which density changes very rapidly with depth is called

Pycnocline

CCD

Calcium Carbonate Compensation Depth

What will be the effect of increasing atmospheric carbon-di-oxide to the position of the CCD in the ocean

CCD will move to shallower ocean - Increased CO2 causes ocean acidification. This lowers the pH and makes the water more corrosive to calcium carbonate, causing the depth at which it dissolves to rise towards the surface

Isopycnals

a line connecting points of specific water density

Isopycnals are what lines

Equal density

δ13C

• “delta C thirteen”

• the stable isotope ratio of carbon-13 to carbon-12

• used to track environmental changes, identify food sources, or study the carbon cycle

blank water mass will have blank δ13C

• Younger water mass will have low δ13C

• Relates to the aging of water masses as water moves away from the surface and ages organic matter decomposes which releases 12 C thereby lowering the δ13C ratio over time. Younger water masse at the surface generally have higher ratio

Weathering of organic matter would be considered a what of carbon

• Source

• Weathering of organic matter releases sored carbon back into the atmosphere or ocean as CO2 making it a source

Deep Southern Ocean is considered to have stored more carbon during what

• Glacial

• During glacial periods changes in ocean circulation and increased biological pump efficiency allowed the deep southern ocean to sequester significantly more CO2 from the atmosphere

about what percent of the anthropogenic CO2 is taken up by Ocean

• ¼

• While estimates vary sightly by year, the global ocean typically absorbs roughly 25% of annual human produce CO2 emission

What kind of bond holds the O and H in a water molecule

Polar Covalent Bonds

Water Molecule

• One oxygen atoms is negative delta and 8 electron (2 in the inner shell and 6 in the outer shell

• Two hydrogen atoms in a bent V shape with 104.5 degree angle with one electron with positive delta

Bjerrum Plot

Illustrates how the concentrations of different forms of Dissolved Inorganic Carbon (DIC) change relative to the pH of the solution

DIC

Dissolved Inorganic Carbon

Residence Time Formula

Residence time = volume/flow rate

Why is there no deep water forming in the modern North Pacific?

The surface water is too fresh and buoyant (low salinity) to sink, creating a strong density barrier known as a halocline

Silicate Weathering

A natural long term chemical process known as hydrolysis where carbonic acid (formed from atmospheric CO2 and rainwater) dissolves silicate minerals in rocks. It acts as a geochemical sink that converts atmospheric CO2 into stable bicarbonates, transferring them to the ocean, where they are stored

What kind of process would expedite silicate weathering?

• Increase surface area - grinding rocks and spreading them out

• Raise temperatures - chemical reaction proceed faster at high temperatures

Describe the role of biological and carbonate pump in ocean carbon cycle (address how these processes control of pCO2 of surface ocean)

The pumps move carbon from the surface to deep ocean. The biological pump withdraw organic carbon, decreasing surface pCO2, while carbonate pump transports inorganic carbon downward, which increases surface pCO2.

Why does water reach its maximum density at 4C?

4C marks the precise balancing point between two opposing molecular forces : thermal expansion and the formation of hydrogen-bonded cluster

Lysocline

depth where the rate of calcite dissolution increases dramatically

What are the primary assumptions of Stroke’s Law?

That the particle is a rigid, smooth sphere moving through a viscous, homogeneous, and infinite fluid at very low speed