Earth and Ocean Sciences Midterm Review

Vocabulary practice flashcards covering ocean circulation, waves, tides, coastal geology, fluvial systems, marine life, and primary productivity from Earth and Ocean Science lectures and exams.

Troposphere

The lowest layer of the atmosphere, where all weather occurs.

Tsunami

A fast-moving ocean wave generated by undersea seismic activity.

Storm Surge

The aspect of a hurricane responsible for causing the most damage.

Mixed Tidal Pattern

A tidal pattern consisting of two high tides and two low tides per day with varying tidal ranges.

Polar Easterlies

The prevailing wind belts that blow from the east between $60^\text{o}$ and $90^\text{o}$ latitude.

Ocean Surface Water pH

The average pH of ocean surface water, which is $8.1$.

Westerlies

The prevailing wind belts that blow from the west between $30^\text{o}$ and $60^\text{o}$ latitude.

Average Seawater Salinity

The average salt content of seawater, measured at $35\,\text{ppt}$.

Ferrel Cells

The atmospheric circulation cells located between $30^\text{o}$ and $60^\text{o}$ latitude.

Western Boundary Currents

Fast-moving, warm-water currents moving away from the equator that form the western boundary of a subtropical gyre, such as the Gulf Stream.

Orbital Waves

The type of ocean surface waves where water particles move in closed circular orbits.

Albedo Effect

The phenomenon where incoming solar radiation is absorbed by darker surfaces (like asphalt) and reflected by lighter surfaces (like ice floes).

Ekman Spiral

The wind-driven motion of ocean water where surface water moves at a $45^\text{o}$ angle to the wind, with the deflection angle increasing and velocity decreasing at greater depths.

Coastal Upwelling

A coastal oceanographic process in which persistent winds dispel warm surface waters, allowing nutrient-rich, deep cold water to rise to the surface.

Coriolis Effect

The apparent deflection of moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere caused by Earth's rotation.

Ocean Eddies

Rings of warm or cold water that pinch off from looping ocean currents.

Plunging Breaker

A wave that breaks over a steep shoreline, causing the crest to curl over and form a distinctive air tunnel.

Spilling Breaker

A wave that breaks gradually over a gently sloping shoreline.

Pycnocline

A subsurface layer of the ocean characterized by a rapid change in water density with depth.

Tropical Storm

An organized cyclonic storm system characterized by sustained winds between $38$ and $74\,\text{miles per hour}$ and lacking a clearly defined eye.

Trade Winds

The global wind belts blowing from the northeast and southeast that converge near the equator.

Resultant Force

The net tide-generating force defined as the mathematical difference between gravitational force and centripetal force.

Perihelion

The point in Earth's orbit when it is closest to the Sun, which increases the tidal range.

Apogee

The point in the Moon's orbit when it is furthest from the Earth, resulting in a decreased tidal range.

Eastern Boundary Currents

Slow-moving, cold-water currents traveling toward the equator that form the eastern boundary of a subtropical gyre.

Wave Height

The vertical distance measured between the crest and the trough of a wave.

El Niño

A climatic condition during which trade winds weaken, ocean waters warm, the Pacific warm pool shifts eastward toward South America, and Atlantic hurricane development is suppressed.

La Niña

A climatic condition characterized by strengthened trade winds, cooler equatorial waters, low vertical wind shear, and favorable conditions for Atlantic hurricane formation.

Deep-Water Waves

Ocean waves traveling in water whose depth is greater than the wave base, featuring circular orbits that diminish in size with depth.

Shallow-Water Waves

Waves traveling in shallow water where the seafloor physically interferes with and flattens orbital particle motion.

Holoplankton

Planktonic organisms that spend their entire life cycle drifting in the plankton community.

Meroplankton

Organisms that spend only a portion of their life cycle as plankton, typically during larval or juvenile stages.

Phytoplankton

Microscopic, autotrophic marine plankton that produce their own organic food via photosynthesis.

Zooplankton

Heterotrophic marine plankton that must feed on other organisms for energy.

Redfield Ratio

The atomic ratio of carbon to nitrogen to phosphorus found in marine phytoplankton: $106\,\text{C} : 16\,\text{N} : 1\,\text{P}$.

Dinoflagellates

Single-celled marine organisms responsible for harmful algal blooms known as red tides.

Zooxanthellae

Symbiotic dinoflagellate algae that live within the tissues of reef-building corals.

Stromatolites

Ancient layered trace fossils produced by sediment-trapping mats of cyanobacteria.

Macroscopic Algae

Large multicellular marine algae commonly referred to as seaweed.

Infauna

Benthic marine animals that live burrowed within the sediment of the seabed, such as clams.

Groin

A shore-protection structure constructed of large, blocky materials perpendicular to the beach to impede longshore sand drift.

Jetty

An engineered barrier built perpendicular to the coastline, usually in pairs, to protect harbor entrances from sediment accumulation.

Seawall

A massive, costly coastal defense structure built parallel to the shore to armor the coast against wave attack and flooding.

Breakwater

A hard coastal structure constructed parallel to the shoreline to absorb incoming wave energy and protect harbors.

Stenohaline

Describing aquatic organisms capable of tolerating only narrow or small variations in salinity.

Countershading

A camouflage pattern where an organism possesses a dark dorsal surface and a light ventral underside to blend in against the ocean depths and the sunlit surface.

Fjord

A steep-sided, deep drowned glacial valley formed by glacial erosion and subsequent sea-level inundation.

Glacial Erratic

An ice-transported boulder deposited by a glacier that differs in lithology from the local bedrock underneath.

Phreatic Zone

The subsurface region (zone of saturation) in which all pores and rock fractures are completely filled with water.

Atoll

A circular coral reef structure enclosing a central lagoon and surrounded by deep open ocean water.

River Delta

A depositional landform composed of sediment accumulated at the mouth of a river as it enters standing water.

Drainage Basin

The total land area drained by a river system and all of its associated tributaries, bounded by drainage divides.

Foreshore

The intertidal zone of a beach exposed between normal high tide and normal low tide.

Backshore

The upper, dry zone of a beach extending landward from the mean high-tide line to the coastline.

Barrier Island

A long, narrow offshore deposit of sand running parallel to the mainland coast, characteristic of depositional shorelines.

Bed Load

Sediment particles moving along the river bottom by sliding, rolling, or saltating.

Suspended Load

Fine sediment particles maintained in the water column by fluid turbulence and carried downstream without touching the bed.

Dissolved Load

The portion of a stream's total sediment load transported as ions in chemical solution.

Oxbow Lake

A crescent-shaped lake created when a meandering river loop is abandoned after a stream cuts through its narrow neck.

Eutrophication

The ecological process wherein excess nutrient loading causes rapid algal blooms, which shade native vegetation and deplete dissolved oxygen upon decomposing.

Sea Ice

Frozen ocean water that forms, floats, and melts entirely in the marine environment, exerting no direct net effect on global sea levels.

Glacial Ice

Compressed, recrystallized snow that accumulates on terrestrial landmasses; its melting directly contributes volume to global sea-level rise.