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Glossary of Chemical Oceanography Terms
Nonconservative Element: An element whose concentration varies from place to place in
the oceans. The variations are caused by variable inputs or reactivity (e.g., uptake
by organisms or inputs from hydrothermal vents).
Normality (N): The equivalents of a solute per liter of solution.
Orca Basin: A deep basin located in the Gulf of Mexico south of Louisiana. Contains
high- salinity and anoxic brines formed from the dissolution of evaporites.
Oscillator: An instrument used to measure the frequency.
Particulate Material: Solid material that does not pass through a 0.45-μm filter. Can be
either organic or inorganic material.
Phase: The different physical states of a compound or element.
Practical Salinity Scale: The salinity defined by the conductivity ratio of seawater relative
to a given mass of KCl. Salinity is a ratio or fraction of masses and does not have
a scale.
Refractive Index: A dimension quantity that is related to how much light is reflected by a
substance. A method used for determining salinity.
Resistance: The resistance R = V/ i where V = potential (volts) and i = current (amps).
Salinity/ Chlorinity Relations: A relationship between salinity and chlorinity. Different
for various estuaries. For open ocean waters, it is assumed to be S = 1.80655 Cl.
Salinometer: An instrument used to measure salinity.
Sea Salt: The inorganic salts found in seawater; primarily NaCl and MgSO 4 .
Solid: The material that does not pass through a 0.45-μm filter.
Solute: A molecule or compound that is dissolved in solution.
Specific Conductance: Defined as Lsp = k/ R = l/ AR, where R is the cell resistance, the cell
constant = k distance (l) between electrodes/ cross- sectional area (A).
Standard Mean Ocean Water (SMOW): Water collected in the deep ocean used as a reference sample for the isotope determination of the D:H and 18 O: 16 O ratios in natural
waters. Used to determine δ = [(R sample / R SMOW ) – 1]1000 where R gives the relative
isotopic ratios of a sample, which can be used to examine changes in isotopes of
H and O.
Submarine Volcanism: Undersea volcanoes that occur at ridge areas. The vent water
coming from these systems has a composition different from seawater due to reactions occurring between seawater and molten basalts.
Trace Components: The components of seawater with concentrations 0.05 to 50 nM.
Tritium: An isotope of hydrogen ( 3 H) that is used as a tracer in water. It is radioactive with
a half- life of 12.5 yr.
Weight Fraction (X): The fraction of the mass of a substance in a mixture (X = g i /∑g i ).
Wheatstone Bridge: Used to measure the resistance of a solution in a conductivity cell.
World River Water: The composition of waters representative of the average river water
entering the oceans.
III. Minor Elements in Seawater
Active Uptake: The uptake of elements by organisms that need them (NO 3 , PO 4 ).
Adsorption: The formation of a thin layer of a substance that is held on the surface of a
solid because of a combination of physical and weak chemical forces.
Glossary of Chemical Oceanography Terms
Nonconservative Element: An element whose concentration varies from place to place in
the oceans. The variations are caused by variable inputs or reactivity (e.g., uptake
by organisms or inputs from hydrothermal vents).
Normality (N): The equivalents of a solute per liter of solution.
Orca Basin: A deep basin located in the Gulf of Mexico south of Louisiana. Contains
high- salinity and anoxic brines formed from the dissolution of evaporites.
Oscillator: An instrument used to measure the frequency.
Particulate Material: Solid material that does not pass through a 0.45-μm filter. Can be
either organic or inorganic material.
Phase: The different physical states of a compound or element.
Practical Salinity Scale: The salinity defined by the conductivity ratio of seawater relative
to a given mass of KCl. Salinity is a ratio or fraction of masses and does not have
a scale.
Refractive Index: A dimension quantity that is related to how much light is reflected by a
substance. A method used for determining salinity.
Resistance: The resistance R = V/ i where V = potential (volts) and i = current (amps).
Salinity/ Chlorinity Relations: A relationship between salinity and chlorinity. Different
for various estuaries. For open ocean waters, it is assumed to be S = 1.80655 Cl.
Salinometer: An instrument used to measure salinity.
Sea Salt: The inorganic salts found in seawater; primarily NaCl and MgSO 4 .
Solid: The material that does not pass through a 0.45-μm filter.
Solute: A molecule or compound that is dissolved in solution.
Specific Conductance: Defined as Lsp = k/ R = l/ AR, where R is the cell resistance, the cell
constant = k distance (l) between electrodes/ cross- sectional area (A).
Standard Mean Ocean Water (SMOW): Water collected in the deep ocean used as a reference sample for the isotope determination of the D:H and 18 O: 16 O ratios in natural
waters. Used to determine δ = [(R sample / R SMOW ) – 1]1000 where R gives the relative
isotopic ratios of a sample, which can be used to examine changes in isotopes of
H and O.
Submarine Volcanism: Undersea volcanoes that occur at ridge areas. The vent water
coming from these systems has a composition different from seawater due to reactions occurring between seawater and molten basalts.
Trace Components: The components of seawater with concentrations 0.05 to 50 nM.
Tritium: An isotope of hydrogen ( 3 H) that is used as a tracer in water. It is radioactive with
a half- life of 12.5 yr.
Weight Fraction (X): The fraction of the mass of a substance in a mixture (X = g i /∑g i ).
Wheatstone Bridge: Used to measure the resistance of a solution in a conductivity cell.
World River Water: The composition of waters representative of the average river water
entering the oceans.
III. Minor Elements in Seawater
Active Uptake: The uptake of elements by organisms that need them (NO 3 , PO 4 ).
Adsorption: The formation of a thin layer of a substance that is held on the surface of a
solid because of a combination of physical and weak chemical forces.