Marine Science - Key Vocabulary (Lecture Notes)

Vocabulary flashcards covering key terms from the marine science notes (Pages 1–23), focusing on definitions and core concepts.

Marine Science

An interdisciplinary study of ocean environments and processes, integrating biology, chemistry, geology, physics, and atmospheric science; uses math to describe and forecast marine phenomena.

psu (practical salinity unit)

A unit used to express salinity in seawater (salinity typically measured in psu; seawater salinity is often described in these units).

Qualitative data

Observations and written descriptions that do not involve numerical measurements.

Quantitative data

Numerical measurements and numerical descriptions of phenomena.

Dimensional analysis

A method to convert between unit systems using conversion factors.

Conversion factor

A fraction that relates two different units so you can translate between them (e.g., 1 inch = 2.54 cm).

Density of seawater (35 ppt, 25°C)

1.023 g/cm³, which is equivalent to 1.023 kg/L under those conditions.

kg/L

A unit of density expressed as kilograms per liter.

Reservoir (hydrologic cycle)

A location where water resides (oceans, atmosphere, groundwater, etc.).

Residence Time

The time a molecule spends in a reservoir; calculated as total amount in the reservoir divided by total input or output rate.

Radiometric dating

A modern geochemical method that determines ages of geological materials using radioactive isotopes.

Half-life

The time required for half of a radioactive parent isotope to decay.

Earth’s age (approx.)

About 4.5–4.6 billion years.

Inner core

A solid sphere at Earth’s center, composed mainly of iron and nickel.

Outer core

A liquid iron-nickel layer surrounding the inner core; generates Earth’s magnetic field.

Mantle

Layer between crust and core; includes the rigid lithosphere and the ductile asthenosphere.

Lithosphere

Rigid outer shell of Earth (crust plus uppermost mantle).

Asthenosphere

Part of the mantle beneath the lithosphere that behaves plastically and allows plate movement.

Moho (Mohorovic Discontinuity)

The boundary between the crust and mantle.

Continental crust

Less dense, thicker crust (~roughly 40 km on average).

Oceanic crust

More dense, thinner crust (~roughly 7 km on average).

Isostasy

Buoyant support of the lithosphere by the asthenosphere; explains vertical movement of plates.

Plate tectonics

Theory that Earth’s lithosphere is divided into plates that move atop the asthenosphere, interacting at boundaries.

Continental Drift

Wegener’s theory that continents were once connected in a supercontinent (Pangaea) and drifted apart.

Pangaea

The supercontinent that existed about 200–250 million years ago.

Seafloor spreading

New lithosphere forms at mid-ocean ridges; older seafloor moves away from ridges and is recycled in trenches.

Mid-Ocean Ridge

Undersea mountain ranges where new ocean crust is formed during seafloor spreading.

Trenches

Deep ocean trenches where subduction occurs, recycling crust back into the mantle.

Paleomagnetism

Study of Earth's past magnetic field recorded in rocks as they form.

Magnetic polarity stripes

Alternating normal and reversed magnetic polarity on either side of mid-ocean ridges, recording geomagnetic reversals.

Bathymetry

Measurement of ocean depths and the mapping of the seafloor topography.

Seamount

An underwater volcano or rise on the seafloor; a flat-topped seamount is called a guyot.

Continental margins

Edges of continents where the ocean meets land, including shelf, slope, and rise.

Continental shelf

Gentle, relatively flat region extending from the shore to the shelf break.

Continental slope

Steep transition from shelf to deeper ocean, found at the shelf break.

Continental rise

Peripheral region between the continental slope and the deep ocean floor, composed of deposited sediments.

Active margin

Narrow, deep margins with plate interactions (trenches, volcanism).

Passive margin

Wide, tectonically quiet margins with little plate interaction.

Neritic sediments

Sediments on the continental shelf, with varied grain sizes and sources.

Pelagic sediments

Fine-grained sediments deposited on the deep ocean floor.

Lithogenous (terrigenous) sediments

Sediments derived from land (rock fragments and minerals).

Biogenous sediments

Sediments formed from the accumulation of biological material (shells, bones, scales). ooze must contain ≥30% remains.

Ooze

Sediment composed of a significant fraction of remains from organisms; calcereous or siliceous varieties are common.

Calcareous ooze

Biogenous sediment rich in calcium carbonate.

Siliceous ooze

Biogenous sediment rich in silica (silicon dioxide).

Water molecule (H2O)

Oxygen atom bonded to two hydrogen atoms; a polar, non-linear molecule.

Hydrogen bond

A weak bond between the hydrogen of one water molecule and the oxygen of another, forming a 3D network.

temperature

the average kinetic energy in all atoms in a substance

heat

the total kinetic energy of all atoms in the substance;

calorie

a unit of heat energy defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius.

80 calories

how many calories does it take to go from solid water to liquid water

540 calories

how many calories does it take to move from water to water vapor

latent heat

the amount of energyneeded to break all the bonds during a change of state

latent heat of vaporization

amount of energy required to go from water vapor to liquid water

latent heat of fusion

amount of energy required to go from liquid water to ice

high latent heat

means that water as a liquid is a stable habitat and the heat required to move the entire volume from liquid to gas is unlikely to occur because it is very large

specific heat

the quantity of heat required to produce a unit change of temperature in a unit mass of material

1 calorie per gram per degree Celsius

what is water’s specific heatheat

heat capacity

quantity of heat required to produce a unit of change of temperature in a substance

mass/volume

what is density

15 degree Celsius

as temperature decreases, the kinetic energy is reduced and the water molecules slow down and more water molecules can fit in a unit volume because they are less energetic; more hydrogen bonds can form

20 degrees Celsius

the water molecules have some kinetic energy and are moving but there are osme hydrogen bonds that are formed

4 degree Celsius

maximum number of water molecules per unit volume. Because the water has less kinetic energy, but still enough kinetic energy to prevent all water molecules from being in a hydrogen bond

0 degrees celsius

the fewest water molecules per unit volume; because the structure or matrix from the hydrogen bonds spreads the molecules out and the molecules have the least kinetic energypp

ppt

parts per thousandpsu

psu

practical salinity unit

35 ppt

what is the salinity of ocean water?

dissolve

the separation of water molecules from each other because the water molecules are attracted to the salt ions and they pull the salt molecules apart

increase

does salt increase or decrease the density of water?

decreases

as temperature increases, water density….

conduction (ex. cold spoon in hot chocolate)

heat is applied at one location; molecules at that location absorb the heat and pass it to the molecules next to them

convection (ex. ceiling fans)

a fluid is heated and that group of molecules takes the heat iwth it to a new location

radiation (ex. radiant energy from the sun)

a volume is heated because it comes into contact with a heat source; the effects may be localized or restricted to the area of direct contact