This week I have compiled an ocean glossary to aid in better understanding terms in ocean-related roles.
| Term | Definition |
| abyssal plain | the flat seafloor of the deep ocean, typically beyond the limits of the continental slopes |
| abyssal zone | the region of the seafloor between 4000-6000 m |
| aeolian | processes related to transportation and deposition of sediments by wind |
| anoxia | conditions of zero or extremely low dissolved oxygen, usually below 0.5 mg/L |
| anthropogenic | resulting from the influence of humans |
| aphotic zone | depths beyond 1000 m where there is no light penetration |
| atoll | a ring-shaped carbonate (or coral) reef or series of islands |
| barrier island | a long, thin island parallel to the shore, created through the deposition of sand |
| basalt | a volcanic rock that makes up much of the oceanic crust |
| bathyal zone | the region of the seafloor from the shelf break to 4000 m |
| bathymetry | pertains to measuring the depths of the ocean |
| bathypelagic zone | the moderately deep parts of the open ocean, between 1000 and 4000 m |
| benthic | refers to the environment of the seafloor |
| benthos | refers to the community of organisms living on or in the ocean floor |
| biogenous sediment | sediment created from the remains of organisms |
| boundary currents | ocean currents whose properties are influenced by the presence of a coastline |
| brackish | seawater of low salinity; part fresh water, part seawater |
| calcareous sediment | sediments composed of calcium carbonate, often from the shells of marine organisms |
| calving | when ice breaks off of the front of a glacier and collapses into the water |
| constructive interference | where the interaction of multiple waves creates waves larger than any of the component waves |
| continental rise | the area at the bottom of the continental slope, where it transitions to the abyssal sea floor |
| continental shelf | the shallow (typically less than 200 m) and flat sub-marine extension of a continent |
| continental slope | the steeper part of a continental margin, that slopes down from a continental shelf towards the abyssal plain |
| Coriolis Effect | the tendency for the path of moving bodies (e.g., ocean currents) to be deflected on the surface of the Earth, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere |
| deep water wave | a wave above a water depth greater than half of its wavelength |
| diatom | photosynthetic algae that make their tests (shells) from silica |
| diatomaceous earth | powdery sediment composed of silica diatom tests |
| diurnal tide | a tidal cycle with only one high and one low tide per day |
| downwelling | process by which surface water is forced downwards |
| dysphotic zone | depths of the water column where there is some light penetration, but not enough to support photosynthesis; corresponds to the mesopelagic zone, 200-1000 m. Also known as the twilight zone |
| eccentricity | in the context of Milankovitch Cycles, the degree to which the Sun is offset from the geometric center of the Earth’s orbit |
| eddy | a rotating water mass |
| El Niño | a periodic climatic situation in which warm water extends all or most of the way to the eastern edge of the equatorial Pacific |
| El Niño-Southern Oscillation (ENSO) | the fluctuating atmospheric conditions that lead to the localized ocean warming of El Niño |
| epipelagic zone | the upper layer of water (0 to 200 m) in areas of the open ocean |
| estuary | a partially enclosed body of water where seawater is diluted by freshwater input |
| euphotic zone | the upper regions of the ocean where there is enough light to support photosynthesis; approximately 0-200 m; also called the photic zone |
| eustatic sea level change | sea level change related to a change in the volume of the oceans, typically because of an increase or decrease in the amount of glacial ice on land |
| evaporites | hydrogenous sediments that form when seawater evaporates |
| fast ice | ice sheets that are attached to land |
| fetch | the distance over which wind blows to form waves |
| fjord | a deep, U-shaped estuary that was carved out by advancing glaciers |
| frequency | the number of waves that pass a point in a given amount of time |
| glacial groove | scratches and grooves carved into bedrock from rocks carried by moving glaciers |
| glacier | a long lasting (centuries or more) body of ice on land that moves under its own weight |
| gyre | a large circular ocean surface current |
| hadal zone | the region of the seafloor below 6000 m |
| hadopelagic (hadalpelagic) zone | region of the open ocean with water depths greater than 6000 m |
| halocline | where there is a dramatic change in salinity over a small change in depth |
| harmful algal bloom (HAB) | when phytoplankton appear in very high concentrations with potentially hazardous consequences such as mass die-offs or toxicity |
| hypoxia | a condition with low dissolved oxygen, usually defined as oxygen levels below 2 mg/L |
| intertidal zone | the region of a coast between the high and low tide lines. Also called the littoral zone |
| knot | one knot (kt) = 1 nautical mile per hour = 1.15 mph = 1.85 kph |
| La Niña | a periodic climatic situation in which colder than normal water extends throughout the equatorial Pacific |
| Mercator projection | a map projection where latitude and longitude are both represented as straight, parallel lines intersecting at right angles |
| Milankovitch cycles | millennial-scale variations in the orbital and rotational parameters of the Earth that have subtle effects on the Earth’s climate |
| nautical mile | a distance equal to one minute of latitude; equivalent to 1.15 land miles or 1.85 km |
| neritic | the marine pelagic province from the low tide line to the shelf break |
| net production | total primary production minus the organic compounds used up by respiration by the producers |
| North Atlantic Deep Water | deep Atlantic Ocean water that has descended in the far north of the basin in the area between Scandinavia and Greenland |
| ocean acidification | where the overall pH of the ocean declines, likely due to an increased amount of carbon dioxide in the ocean |
| photic zone | the upper regions of the ocean where there is enough light to support photosynthesis; approximately 0-200 m; also called the euphotic zone |
| Polar Cell | the atmospheric convection cells between 60 degrees latitude and the pole |
| polyna | an area of persistent open water in areas otherwise covered with ice |
| seamount | a submerged mountain rising from the seafloor |
| semidiurnal tide | a tidal cycle with two high and two low tides per day, each of roughly equal heights |
| shelf break | the boundary between the continental shelf and continental slope, where the angle of the seafloor begins to get steeper |
| siliceous sediment | sediment dominated by particles of silica, often from the shells of marine organisms |
| thermocline | a region in the water column where there is a dramatic change in temperature over a small change in depth |
| thermohaline circulation | deep ocean circulation driven by differences in water density |
| upwelling | process by which deeper water is brought to the surface |
Below is a video that uses many ocean terms. This is example of how understanding ocean-related terms help for a deeper understanding of climate and ocean sciences:
Sources:
https://oceaninfo.com/glossary/
https://rwu.pressbooks.pub/webboceanography/back-matter/glossary-2/
https://www.usgs.gov/glossary/ocean-glossary
https://www.open.edu/openlearn/science-maths-technology/the-oceans/content-section–glossary
