EAS 1600 Exam 2 Vocabulary Review

Comprehensive vocabulary flashcards covering hydrologic processes, groundwater, ocean dynamics, ENSO, marine hazards, water pollution, and federal environmental legislation.

Continentality

The climatic effect whereby coastal locations record a narrower range of temperatures than inland regions, causing areas farther from the ocean to experience more extreme high and low temperatures.

Sea breeze

A daytime local wind created when solar radiation warms land faster than the sea, causing air to rise over the land and cooler air to flow inland from the sea.

Land breeze

A nighttime local wind created when the ocean remains warmer than the cooled land surface, causing air to rise over the sea and air to blow offshore from the land.

Specific heat capacity (water)

The quantity of thermal energy required to raise the temperature of $1\,\text{g}$ of $H_2O$ by $1\,^\circ\text{C}$. Water possesses the highest specific heat capacity of any common liquid ($1\,\text{calorie} = 4.184\,\text{J}$).

Sensible heat

The heat energy required to alter the temperature of a substance without causing a change in its physical phase.

Latent heat

Heat energy absorbed or released by a substance during an isothermal transition from one physical phase to another.

Natural eutrophication

The slow, natural aging and filling-in of a lake basin with sediments and nutrients over centuries.

Cultural eutrophication

Accelerated nutrient loading and sedimentation in aquatic bodies caused by anthropogenic inputs of nitrogen and phosphorus from fertilizers or wastewater, causing algal blooms and subsequent hypoxia.

Watershed

The distinct geographic land catchment area that drains all incoming surface water and runoff into a common river system, bounded by topographic divides.

Water table

The subsurface boundary that separates the upper unsaturated zone (where pore spaces contain air and water) from the underlying saturated zone (where all voids are filled with groundwater).

Recharge

The hydrologic process in which surface water infiltrates the soil and percolates downward to replenish an aquifer.

Discharge (groundwater)

The upward or lateral emergence of subsurface groundwater into surface water bodies, such as through natural springs or stream beds.

Gaining stream

A stream whose channel bottom intersects a local water table situated at a higher elevation, receiving groundwater discharge directly into its flow.

Losing stream

A stream positioned above the regional water table that continuously loses surface water to the subsurface via downward infiltration.

Porosity

The volumetric proportion of open, void space present within an aggregate rock or unconsolidated sediment material.

Permeability

A measure of the ability of a porous geological medium to transmit fluids through interconnected void networks.

Confined aquifer

A permeable water-bearing geologic layer bound above and below by low-permeability confining aquitards, featuring elevated hydrostatic pressure.

Piezometric (potentiometric) surface

The theoretical elevation to which pressurized groundwater within a confined aquifer would rise if unrestrained by overlying impermeable confining strata.

Artesian well

A borehole penetrating a confined aquifer in which groundwater rises above the local ground surface without pumping because the wellhead lies below the potentiometric surface.

Drawdown

The vertical decline in the elevation of the water table or potentiometric surface caused by groundwater extraction exceeding the natural replenishment rate.

Cone of depression

A localized, roughly circular depression in the water table that forms around an actively pumping well.

Subsidence

The permanent compaction of subsurface sediment layers and downward settling of the land surface caused by heavy groundwater extraction.

Ghyben–Herzberg principle

The hydrodynamic ratio ($z = 40 \times h$) stating that for every unit of freshwater head ($1\,\text{ft}$) above sea level, approximately $40\,\text{ft}$ of freshwater exists below sea level to balance denser seawater.

Active sonar

An acoustic bathymetric mapping technique that transmits acoustic pulses through seawater and measures the round-trip travel time of returning echoes from the ocean floor.

Bathymetry

The measurement and cartographic representation of ocean bottom topography and water depths across marine basins.

Passive margin

A continental transition zone lacking active plate tectonic boundaries, characterized by wide continental shelves and minimal seismic activity.

Active margin

A continental boundary aligned with a converging or transform tectonic plate edge, exhibiting frequent seismicity, trenches, and volcanism.

Euphotic zone

The sunlit upper strata of the ocean where solar irradiance is sufficient to support net positive rates of marine photosynthesis.

Dysphotic zone

The intermediate marine depth zone where faint light penetrates but lacks the intensity required to sustain photosynthetic organisms.

Aphotic zone

The deep ocean layer receiving zero sunlight, characterized by perpetual darkness.

VIIRS (Visible Infrared Imaging Radiometer Suite)

A 22-channel satellite imaging radiometer covering $0.41\text{--}12.01\,\mu\text{m}$ wavelengths, deployed to measure sea surface temperatures, atmospheric aerosols, fires, and ocean color.

Thermocline

The vertical zone in a water body characterized by an abrupt, rapid decrease in temperature with increasing depth.

Brine rejection

The exclusion and expulsion of dissolved salts from freezing sea ice, generating high-density, frigid, hyper-saline water that sinks rapidly into the abyssal ocean.

Halocline

A subsurface oceanic layer characterized by a steep, vertical gradient of salinity with increasing depth.

Pycnocline

The oceanic transition zone where density increases sharply with depth as a function of changing temperature and salinity profiles.

Coriolis effect

The apparent deflection of moving air and water currents caused by planetary rotation, deflecting trajectories clockwise to the right in the Northern Hemisphere and counterclockwise to the left in the Southern Hemisphere.

Gyre

A large-scale, closed system of circulating surface ocean currents driven by global trade winds, westerlies, and continental land barriers.

Ekman spiral

A vertical profile of ocean surface currents wherein wind-driven surface water sets underlying layers in motion, each progressively deflected by Coriolis forces with decaying velocity with depth.

Ekman transport

The net column-integrated transport of surface water moving perpendicular ($90^\circ$) to the prevailing wind direction: to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Geostrophic flow

An oceanic current that moves along elevation contours when the horizontal pressure gradient force from mounded water is balanced by the Coriolis force.

Coastal upwelling

The upward movement of deep, cold, nutrient-rich water toward the ocean surface resulting from wind-driven Ekman divergence away from a coastline.

Thermohaline circulation

Large-scale deep ocean conveyor circulation driven by density differences that are controlled by variations in temperature (thermo) and salinity (haline).

AMOC (Atlantic Meridional Overturning Circulation)

The Atlantic basin component of thermohaline circulation that transports warm tropical surface waters northward and returns cold, dense deep water southward.

Antarctic Circumpolar Current

The continuous, wind-driven eastward surface current encircling Antarctica, functioning as the widest and deepest current system on Earth.

El Niño Southern Oscillation (ENSO)

A coupled atmospheric-oceanic oscillation across the equatorial Pacific characterized by alternating warm (El Niño) and cool (La Niña) sea surface temperature phases.

Walker cell

An east–west equatorial atmospheric convection loop in the Pacific driven by sea surface temperature gradients between the warm western Pacific and the cool eastern Pacific.

Relative Oceanic Niño Index (RONI)

The operational metric used to monitor ENSO phases by calculating running 3-month mean sea surface temperature anomalies within the Niño 3.4 region ($120\text{--}150^\circ\text{W}$, $5^\circ\text{N}\text{--}5^\circ\text{S}$).

Bioaccumulation (biomagnification)

The process by which non-biodegradable chemical toxins are retained in organismal adipose tissue and magnified in concentration at sequentially higher trophic levels in a food web.

Maximum sustainable yield (MSY)

The largest theoretical long-term harvest that can be extracted from a wild fish stock without causing its population to decline.

Bottom trawling

An industrial fishing practice involving weighted nets dragged across the seafloor, causing destructive physical damage to benthic habitats and generating substantial bycatch.

Ocean acidification

The ongoing reduction of ocean pH caused by seawater absorbing anthropogenic atmospheric $\text{CO}_2$, which limits calcification in corals and shellfish.

Ocean dead zone

A severely hypoxic or anoxic aquatic region caused by microbial decomposition of excessive algal blooms, depleting dissolved oxygen levels below biological survival thresholds.

Eustatic sea level

The absolute, global mean sea level referenced from Earth's center or the geoid, distinguished from localized relative shoreline changes.

Longshore drift

The lateral transport of sand and coastal sediment parallel to the shore carried by currents operating inside the surf zone.

Storm surge

A severe rise in coastal water levels above normal astronomical tides caused by the forward momentum of storm winds and low atmospheric pressure.

Virtual water

The hidden, indirect volume of freshwater consumed, evaporated, or polluted in the complete supply chain to produce consumer commodities, food, and electricity.

Point source pollution

Stationary, discrete conduits or discharge outlets—such as wastewater effluent pipes or drainage ditches—from which contaminants enter surface waters.

Nonpoint source pollution

Broad, diffuse contamination carried across wide landscape surfaces by urban stormwater runoff or agricultural field drainage.

DNAPL (dense non-aqueous phase liquid)

An immiscible liquid chemical contaminant whose density exceeds that of pure water, causing it to sink through water-saturated porous media to the base of an aquifer.

LNAPL (light non-aqueous phase liquid)

An immiscible liquid contaminant that is less dense than water, causing it to pool and float at the upper boundary of the water table.

PFAS (per- and polyfluoroalkyl substances)

A group of over 12,000 synthetic organofluorine chemical compounds with strong carbon-fluorine bonds that resist natural degradation and persist indefinitely in ecosystems.

Silent Spring

The landmark 1962 environmental book by Rachel Carson that documented the ecological bioaccumulation of synthetic organochlorine pesticides such as DDT.

National Environmental Policy Act (NEPA)

The 1970 federal law requiring federal agencies to conduct Environmental Impact Statements (EIS) and Environmental Assessments (EA) before approving major projects.

Clean Air Act

A 1970 federal environmental statute mandating that the EPA establish National Ambient Air Quality Standards (NAAQS) and regulate emissions from stationary and mobile sources.

Clean Water Act

A 1972 regulatory statute making it unlawful to discharge any contaminant from a point source into navigable surface waters without an authorized NPDES permit.

Safe Drinking Water Act

A 1974 statute authorizing the EPA to establish enforceable drinking water criteria, specifically setting Maximum Contaminant Levels (MCLs) for public distribution systems.

Resource Conservation and Recovery Act (RCRA)

A 1976 federal framework governing the comprehensive 'cradle-to-grave' management, generation, transport, treatment, storage, and disposal of hazardous waste materials.

CERCLA ('Superfund')

A 1980 federal program enacted to fund and manage the emergency remediation of abandoned hazardous waste sites and assign liability to Potentially Responsible Parties.

National Priority List (NPL)

The EPA's formal ranking and inventory of severely contaminated hazardous waste sites prioritized for long-term ecological and public health remediation under CERCLA.