Oceanography Flashcards
Ocean Divisions
The global ocean covers 71% of our planet and is separated into 5 major divisions
- Pacific Ocean
- Artic Ocean
- Atlantic Ocean
- Southern Ocean
- Indian Ocean
Marine Zones
Vertical stratification
Two major marine zones:
Neritic zone -
- Warm, nutrient rich
- From shore to edge of continental shelf
- Contains 90% of all marine species
Oceanic zone -
- All waters beyond continental shelf
- Open ocean
- Only about 5% of marine species discovered
Marine Zones
Horizontal stratification
5 zones
Epipelagic -
0-650 ft deep
Photic zone (LIGHT!)
Mesopelagic -
650-3300 ft deep
The “twilight zone”
Bathypelagic -
3300-13000 ft deep
“Midnight zone”
Little to no light
Abyssopelagic -
13000-20000 ft deep
“Abyssal zone”
Hadalpelagic -
20,000+ ft deep
Deep ocean trenches
Ocean Geomorphy (Topography)
The underwater extension of a continent is called the “continental shelf”
The slop between the outer edge of the “continental shelf” and the deep ocean floor is called “continental slope”
The Atlantic ocean contains many “abyssal plains” and in some areas they may be broken up by deep troughs called “trenches” or isolated underwater mountains called “sea mounts”
“Mid-ocean ridge” is a mountain range underwater where tectonic plates are separating
Unique Properties of Water
Water has several unique properties that make life possible!
1. Ice Floats
- Allows life to survive during cooler times
- Insulates closed bodies of water
- The vast majority (90%) of freshwater can be found in ice
2. High Conduction of Heat
- Takes a LOT of heat to raise temp. of large bodies of water
- Helps regulate extremes
3. Low Viscosity
- Improved ocean circulation
- Allows life to survive in water
4. Universal Solvent
- Allows water to dissolve and transport valuable chemicals, minerals, and nutrients
- Important in establishing salinity
5. Freezing Point of Saltwater is Low
- 28.4 F, low enough it keeps large portions of the ocean from freezing over
- Average temp. at bottom of the ocean is 32 - 36 F
Salinity
Seawater is 96.5% pure water other 3.5% is dissolved solids that rivers carry into the ocean
Salt water is more dense than fresh water therefore, it will sink
High areas of salinity can be found at the bottom of the ocean, and near land masses where erosion/runoff brings abundance of minerals/salt
Ocean Currents
Waters in the ocean move in giant streams called currents
Surface currents are driven by wind, deep water currents are driven by density differences
Coriolis Effect
The deflection of the Earth’s winds and currents by the Earth’s rotation
Causes gyres
Upwellings
A process where cold, nutrient rich water rises to the surface
Commonly occurs in open ocean, and along coast lines
Fertilizes surface water, causes phytoplankton blooms
Ocean Waves
Waves are periodic up and down movements of water that transfer energy
Three things determine wave size
1. Wind speed
2. Distance wind blows
3. Length of time that wind blows
Breakers
Waves that topple over themselves
Tides
Caused by the gravitational forces exerted on the Earth by the Moon and to a lesser extent, the Sun
Three types
1. Diurnal
2. Semidiurnal
3. Mixed
Diurnal Tide
Locations have 1 low tide and 1 high tide each day
Semidiurnal Tide
Locations have 2 low tide and 2 high tides each day
Mixed Tides
Locations have a mixture of diurnal and semidiurnal tides
