EPS SCI 15 - Lab 5 & 7 Study Deck

EPS SCI 15, Spring 2026

Salinity ‰=

1.805(chlorinity‰)

Two things that increase salinity in oceans:

evaporation, ice formation

Two things that decrease salinity in oceans:

rain, ice melting

Density is __ proportional to salinity.

directly

Temperature is __ proportional to salinity.

inversely

Surface water is coldest at the __

poles

Why is concentration of major (chemical) constituents larger in the ocean than rivers?

Ocean collects from rivers and other sources (volcanic gases, hydrothermal fluids at MOR and Rise System), Rivers are constantly changing while the Ocean is a permanent reservoir

Residence time (t_r)=

Amount/Flux

[Residence time]=

years

In the first reaction of CO2 and H20, what is the product? What does this dissolve into?

Carbonic Acid, Bicarbonate ion, Carbonate ion, Hydrogen ions

What does the buffer system do? What ions are involved?

Prevents extreme acidity and alkaline/basicness, Carbonate, Bicarbonate

The polarity of H2O makes it have…

high heat capacity, latent heat, solubility, less density as solid than liquid

Net Primary Productivity (NPP)=

GPP - R

Salt makes the __ and __ __ of H2O more extreme.

melting, freezing points

Euphotic Zone

Photosynthesis > Respiration

Dysphotic Zone

Photosynthesis < Respiration

Aphotic Zone

No Photosynthesis

Compensation Depth

NPP=0

Critical Depth

Integrated photosynthesis of total water column over depth = Intergraded O2 consumption over depth

Nutrients

Phosphorous, Silica, Nitrogen

Carbon : Nitrogen : Phosphorus

106:16:1

Why are the interiors of subtropical gyres the least productive regions of the oceans?

Downwelling, Stratification/low nutrients

3 Trophic Groups

Producers, Consumer, Decomposers

__ eat __(Phytoplankton/Zooplankton)

Zooplankton, Phytoplankton

Light/Dark Bottle Experiment: What’s happening in light bottle? Dark?

photosynthesis and respiration, respiration

Benthic Zone

area associated with seafloor

Pelagic Zone

area of water NOT near bottom or shore of a body of water

Why is tropical productivity low and flat?

permanent thermocline, barrier to vertical mixing and nutrient resupply