Ocean & Coastal Processes Flashcards
Phytoplankton
Microscopic, photosynthetic organisms that form the base of the marine food web; primary producers in the ocean
Zooplankton
Tiny animal plankton that feed on phytoplankton and serve as food for larger marine animals
Food Web
A complex network of interconnected food chains showing energy transfer between marine organisms
Biomass
The total mass of living organisms in a given area or volume; high near coastlines and upwelling zones due to nutrient availability
Invertebrates
Animals without backbones, such as jellyfish, crustaceans, and corals; make up the majority of marine species
Vertebrates
Animals with backbones, such as fish, whales, and dolphins; often higher up in the marine food web
Bathymetry
The measurement of ocean depth and the mapping of the seafloor; reveals underwater features like trenches, ridges, and continental margins
Continental Margin
The submerged outer edge of a continent, consisting of the continental shelf, slope, and rise
Water Column
A vertical section of ocean water from the surface to the bottom, used to study how light, temperature, and pressure change with depth
Intertidal Zone
The coastal area between high and low tide marks; regularly exposed and submerged
Neritic Zone
The shallow ocean zone over the continental shelf; sunlight reaches the bottom and supports high biodiversity
Oceanic Zone
The deep ocean beyond the continental shelf; includes the photic and aphotic zones
Light/Dark Locations in Water
Horizontal: More light near the coast (neritic), less in deep ocean (oceanic); vertical: light penetrates the photic zone (upper ~200m); aphotic zone lies below where no light reaches
Salinity
The concentration of dissolved salts in water; affects density. Higher salinity = higher density
Water Density, Salinity, Temperature, Pressure
Density increases with salinity and pressure, and decreases with higher temperature. Cold salty water is the densest and sinks during downwelling
Oceanic Heat Transfer
Oceans absorb and redistribute heat via surface currents and deepwater circulation, influencing climate
Surface Currents
Horizontal currents driven by global winds and Earth’s rotation; move warm and cold water across oceans
Global Winds
Include 1) trade winds (near equator, east to west), 2) westerlies (mid-latitudes, west to east), and 3) polar easterlies (poles, east to west)
Coriolis Effect
The deflection of moving fluids (like wind and water) due to Earth’s rotation; causes currents to veer right in the Northern Hemisphere, left in the Southern
Gyres
Large circular current systems in ocean basins, shaped by global winds and the Coriolis effect
Rip Currents
A fast, narrow current moving seaward from the shore; dangerous to swimmers, often formed near breaks in sandbars
Thermohaline Circulation
Global deep-ocean circulation driven by differences in temperature and salinity (density); also called the “global conveyor belt”
Downwelling
Occurs when dense surface water sinks, transporting oxygen to deep waters
Upwelling
Occurs when deep, cold, nutrient-rich water rises to the surface, supporting high biological productivity
Waves
Formed by wind; have properties like height, wavelength, and period. Energy moves forward, not water
Constructive Interference
When a wave crest and trough meet, canceling each other out to form a smaller wave
Destructive Interference
When a wave crest and trough meet, canceling each other out to form a smaller wave
Storm Surges
A rise in sea level caused by low pressure and strong winds during storms; can flood coastlines
Tsunami
Large, fast-moving waves caused by undersea earthquakes or landslides. Have long wavelengths and can travel at over 400 mph
Run-Up
The maximum height a tsunami reaches when it comes ashore
Tides
Regular rises and falls in sea level caused by gravitational forces of the moon and sun
High Tides/Low Tides
Daily fluctuations in sea level–two of each occur roughly every 24 hours due to Earth’s rotation
Tidal Range
The vertical difference between high and low tide. Greater in bays and estuaries
Spring Tides
Higher-than-average tides occurring during full and new moons when sun and moon align
Neap Tides
Lower-than-average tides occurring during quarter moons when sun and moon pull at right angles
Reefs
Structures formed by coral or rock near coastlines that provide habitat and slow wave energy
Atoll
A ring-shaped coral reef encircling a lagoon, formed around a sunken volcanic island
Lagoon
A shallow body of water separated from the ocean by a barrier such as a reef or sandbar
Hydrothermal Vents
Openings on the seafloor where heated, mineral-rich water escapes from Earth’s crust; support unique ecosystems
Landforms of Coastal Erosion
Sea cliffs, wave-cut platforms, sea arches, stacks; formed by wave action wearing away rock
Landforms of Coastal Deposition
Beaches, spits, barrier islands, sandbars; created by longshore drift and wave deposition
Examples of Sea-Level Change
Submergent coasts = sea level rise (e.g., fjords, estuaries); emergent coasts = land rises or sea level falls (e.g., raised beaches)
Seawalls
Human-made barriers built along coasts to prevent erosion. They protect land but can increase erosion in adjacent areas
Trieste
A famous deep-sea submersible that descended into the Mariana Trench in 1960, reaching the ocean’s deepest known point
Submersible
A small, manned or unmanned vehicle used to explore the deep ocean, collect data, and observe marine environments
Bottom Trawling
A fishing method that drags heavy nets across the seafloor; damages ecosystems and stirs up sediments
Manganese Nodules
Metal-rich lumps found on the deep ocean floor, potential sources of minerals like manganese, copper, and nickel
