Oceanography (ESCI 1010) Complete Study Guide Flashcards

A comprehensive vocabulary-style flashcard set covering the core concepts of Oceanography including plate tectonics, marine chemistry, ecology, climate systems, and marine policy.

Motivated Reasoning

The cognitive bias where individuals put more effort into disputing information that conflicts with prior beliefs than they put into evaluating information consistent with those beliefs.

Cherry Picking

A misinformation tactic involving the selection of only data that supports a specific conclusion while ignoring contradictory evidence.

Fake Experts

A technique using credentials from an unrelated field as authority to settle questions in a different scientific field.

Dunning-Kruger Bias

A cognitive bias where people with limited knowledge overestimate their own competence.

Big Bang Theory

The origin of the universe predicted by Fr. Georges Lemaître based on Einstein's theory of relativity and detected as cosmic microwave background radiation by Penzias and Wilson.

Heavy Element Origins

Elements between Boron ($\text{B}$) and Iron ($\text{Fe}$) are created inside stars, while elements heavier than iron are made in supernovae.

Hadean Eon

The earliest eon in Earth's history, during which the Moon was formed.

Phanerozoic Eon

The current eon characterized by abundant macroscopic fossils.

Lithosphere

The rigid outer layer of Earth consisting of the crust and the uppermost mantle, which includes the tectonic plates.

Asthenosphere

The partially molten layer beneath the lithosphere on which tectonic plates slide.

Mid-Ocean Ridges

Locations where new oceanic crust is created; they are topographically higher because they are warmer.

Subduction

The process by which oceanic crust is recycled back into the mantle at trenches.

Slab Pull

The primary driver of plate motion where cold, dense subducting slabs drag plates away from ridges.

Ridge Push

A secondary driver of plate motion where topographically elevated ridges cause gravitational sliding away from the ridge center.

Marie Tharp

The first person to map the ocean floor, providing key evidence for plate tectonics.

Mercator Projection

A map projection that preserves angles for navigation but distorts size and position.

Gall-Peters Projection

A map projection that distorts shape but better represents the relative area and position of landmasses.

Goode Homolosine Projection

A projection that preserves area but breaks the Earth's image into discontinuous segments.

Salinity

The dissolved salt content of water; average marine salinity is approximately $35 \text{ PSU}$.

Residence Time

The length of time an ion stays in seawater before being removed; it is the major control on the relative abundance of different elements in the ocean.

Rule of Constant Proportion

The principle that major ions in seawater are in roughly uniform relative proportions throughout the ocean.

Brine Exclusion

The process where surrounding water becomes saltier when ice forms in the ocean.

Euphotic Zone

The uppermost layer of the ocean with sufficient light for photosynthesis.

Disphotic Zone

The 'twilight zone' where light is present but insufficient for photosynthesis.

Pycnocline

The layer of the ocean where density changes rapidly with depth, inhibiting mixing.

Thermocline

The layer of the ocean where temperature changes rapidly with depth.

Coriolis Effect

A phenomenon that deflects motion to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Global Conveyor Belt

The thermohaline deep-water circulation system that takes approximately $1\,000$ years to complete.

Upwelling

The process of deep, nutrient-rich water rising to the surface, supporting primary productivity and fisheries.

Latent Heat

The energy absorbed or released when a material changes phase, such as from solid to liquid.

Tsunami

A wave generated by large displacement events; the largest ever recorded was caused by a landslide.

Neap Tides

The smallest tidal range, occurring when the Moon is perpendicular to the Earth-Sun axis.

Spring Tides

The largest tidal range, occurring when the Earth, Moon, and Sun are aligned.

Gross Primary Productivity (GPP)

The total amount of new organic material produced by primary producers.

Net Primary Productivity (NPP)

Organic material produced by primary producers minus the material they themselves respire.

Nitrogen Fixation

The process of converting $\text{N}_2$ gas into bioavailable ammonium ($\text{NH}_4^+$), performed by cyanobacteria in the ocean.

Diatoms

Plankton with silica (glass) skeletons that are important primary producers in high-nutrient environments.

Coccolithophores

Plankton characterized by calcium carbonate (calcareous) skeletons.

Marine Snow

Dead/decaying organic matter and fecal pellets that sink from the surface to the deep ocean.

Microbial Loop

The process where organic matter is consumed by bacteria as it decays, making it available to higher organisms rather than sinking.

Biological Pump

The mechanism by which carbon is moved from the surface ocean to the deep sea via sinking organic matter.

Porifera

The phylum of sponges; most primitive animals that lack true tissues and are asymmetrical.

Cnidaria

The phylum including jellyfish and corals, characterized by stinging cells (nematocysts) and radial symmetry.

Mollusca

The most diverse marine phylum, including clams, snails, and octopuses, characterized by a mantle.

Arthropoda

The largest phylum, characterized by exoskeletons and jointed limbs, including crabs, shrimp, and krill.

Echinodermata

The phylum including sea stars and urchins, characterized by 5-fold (pentamerous) radial symmetry and tube feet.

Nekton

Organisms that swim actively against currents.

Plankton

Organisms that drift or weakly swim in the water column.

Keystone Species

A species that has a disproportionately large ecological effect relative to its abundance, such as sea otters or sea stars.

Trophic Efficiency (10% Rule)

The principle that approximately $10\,\%$ of energy passes from one trophic level to the next.

Zooxanthellae

Photosymbiotic dinoflagellate algae living inside reef-forming coral tissue that provide the coral with food.

Atolls

Ring-shaped reefs with a central lagoon formed as coral growth keeps pace with sea level rise while a volcano erodes.

Coral Bleaching

A phenomenon where stressed corals expel their zooxanthellae and turn white, often due to high temperatures.

Ocean Acidification

The decrease in seawater $\text{pH}$ caused by the addition of $\text{CO}_2$, which forms carbonic acid ($\text{H}_2\text{CO}_3$).

Functionally Extinct

A status where a species still exists but is no longer abundant enough to perform its ecological role.

Osteichthyes

Bony fish with skeletons of calcium phosphate; includes ray-finned fish, lobe-finned fish, and humans.

Odontocetes

Toothed whales, such as dolphins and orcas, which act as predators.

Mysticetes

Baleen whales that are filter feeders, using keratin baleen to consume large quantities of prey.

Whale Pump

The process by which whales recycle nitrogen and carbon by feeding at depth and excreting near the surface.

Chemosynthesis

The process by which life generates new organic matter from chemical gradients without light, typical of hydrothermal vents.

Bioluminescence

Light emitted by living organisms, used to attract mates or prey and for defense in the deep sea.

Greenhouse Effect

The trapping of heat near Earth's surface as greenhouse gases allow short-wavelength visible light to pass through but are opaque to long-wavelength infrared radiation.

Eunice Foote

The person who, in $1856$, first described and experimentally demonstrated the greenhouse effect.

Climate Forcing

A factor, such as $\text{CO}_2$, that drives temperature change independent of the current temperature.

Climate Feedback

A process that responds to changes in temperature and amplifies or reduces the effect, such as water vapor or ice albedo.

Milankovitch Cycles

Natural orbital cycles including Eccentricity ($100\,000$ years), Axial Tilt ($41\,000$ years), and Precession ($26\,000$ years) that drive glacial periods.

Albedo

The fraction of total solar radiation reflected by a surface; ice has a high value, reflecting more light.

Paleoclimate Proxies

Methods such as ice cores and foraminifera shells that provide information about historical climates not directly measured.

ENSO (El Niño Southern Oscillation)

A cycle of climate variability in the Pacific comprising Normal, El Niño, and La Niña states.

Storm Surge

A coastal rise in water level during a hurricane, which is the primary cause of hurricane-related deaths.

National Flood Insurance Program (NFIP)

A US program that has become a net financial loss due to outdated flood maps and incentivized development in high-risk areas.

Thermal Expansion

The primary driver of current sea level rise (approximately $60\,\% - 70\,\%$), where warming water increases in volume.

Marine Defaunation

The population decline of marine fish, estimated at $38\,\% - 40\,\%$ since the $1950\text{s}$.

Catch Per Unit Effort (CPUE)

A key indicator of fish population size; its decline signals overfishing.

Purse Seine

A fishing method where a net encircles a school of fish and the bottom is drawn tight.

Tragedy of the Commons

The overexploitation and collapse of a shared resource as individuals maximize personal gain while spreading the harms to the group.

CITES

The international treaty implemented in the USA through the Endangered Species Act.