Study Guides (Chapter 2,3, and 4) Flashcards
Combining all information from the textbooks to memorize
What are the major oceans and their locations?
Pacific Ocean (largest, between Asia/Australia and the Americas), Atlantic Ocean (between the Americas and Europe/Africa), Indian Ocean (between Africa, Asia, and Australia), Southern Ocean (surrounding Antarctica), Arctic Ocean (north of North America, Europe, and Asia).
Why is the ocean crust the same age on opposite sides of a mid-ocean ridge?
New sea floor forms at the ridge through seafloor spreading. As magma rises, it solidifies and moves outward equally on both sides.
What process causes the formation of trenches?
Trenches form at subduction zones where a denser oceanic plate sinks beneath a lighter continental plate due to plate tectonics.
What is plate tectonics?
Earth’s lithosphere is divided into plates that move due to convection currents in the mantle, creating ridges, trenches, earthquakes, and volcanoes.
What happens to plate material after it subducts or comes out of spreading zones?
It melts and can either rise as magma to form volcanoes, create mountains, or resurface through spreading zones.
Why are oceanic plates ‘younger’ than continental ones?
Oceanic crust is constantly recycled at subduction zones, whereas continental crust remains intact for billions of years.
What are the classifications of general ocean habitats?
Continental Shelf (shallow, near the coast), Continental Slope (steep drop-off), Continental Rise (sediment accumulation), Abyssal Plain (deep, flat ocean floor).
What are active vs. passive margins?
1) Active Margins (West Coast U.S.): Tectonic activity, narrow shelf, deep trench. 2) Passive Margins (East Coast U.S.): No tectonic activity, wide shelf, gradual slope.
What are the different realms in marine biology?
Pelagic: Open ocean, deep waters. Coastal: Nearshore, shallow areas. Intertidal: Between tides, exposed at low tide.
What is the photic zone?
The sunlit upper layer where photosynthesis occurs, supporting marine life.
What makes water special?
High heat capacity (absorbs heat without major temperature changes), Polarity (dissolves substances easily), Ice is less dense than liquid water, allowing it to float.
How does water density change?
Cold water is denser than warm water, but ice is less dense than liquid water. Salinity increases density (saltier water sinks).
What processes add or subtract oxygen into or out of the ocean?
Oxygen is added by photosynthesis and wave mixing; removed by respiration.
What causes ocean salinity?
Erosion of rocks and volcanic activity release minerals (NaCl).
Why are ocean surface currents stronger on the west side of oceans?
Coriolis effect pushes warm currents toward the western ocean edges (e.g., Gulf Stream).
What is a thermocline?
A layer where temperature changes rapidly with depth, affecting water circulation and marine life.
What is diffusion and osmosis?
Diffusion: Movement of molecules from high to low concentration. Osmosis: Movement of water across membranes (important for marine organisms).
What happens to oxygen levels as you go deeper in the ocean?
Oxygen decreases in deeper water due to respiration, with an Oxygen Minimum Layer occurring where respiration outpaces oxygen input.
What causes the oxygen minimum layer?
Occurs between 200-1,000m due to high respiration, lack of photosynthesis, and limited water mixing.
What is deep ocean circulation driven by?
Originates at the poles (North Atlantic and Antarctica) due to sinking of cold, salty, dense water.
What are the properties of sound in water?
Sound travels faster and farther than in air, used by marine animals for communication and echolocation.
What causes waves?
Generated primarily by wind; affects coastal erosion and transport of sediments.
What is upwelling?
Deep, nutrient-rich water rises to the surface, supporting high productivity.
What causes upwelling along the western margins of continents?
Driven by Ekman transport and Coriolis effect, where winds push surface water away, allowing nutrient-rich deep water to rise.
