Unit 3.2: The World's Five Oceans Flashcards
The worlds 5 oceans cover what percentage of earths surface? What percentage of the biosphere does it have?
Covers over 70% of earths surface and contains 99% of the earths biosphere.
What are the 5 oceans and what percentage of total ocean do they have?
- Pacific: 46%
- Atlantic: 25%
- Indian: 20%
- Southern: 6%
- Arctic: 3%
What is the difference between these bodies of water that all contain salt water?
- ocean
- sea
- bay
- gulf
- sound
- strait
- Ocean: very large expanse of water that is composed of salt water.
- Sea: Large body of salt water bounded by land masses
- Bay: Inland sea with relatively calm surfaces. Land surrounds it on 3 sides.
- Gulf: Larger than a bay, land on all 3 sides
5: Sound: Long body of deep water that usually connects two bodies of water. - Strait: Narrow passage connecting 2 bodies of water.
What are the 5 different properties of the ocean?
- Light penetration: Measure of how deep in water column light can penetrate. Shortwave can penetrate the deepest.
- Water pressure: water pressure increases the deeper in the water column you go. Increases by 1kg/cm^2 for each 10 m of depth. This is also known as a BAR.
- Salinity: The concentration of dissolved minerals in the sea water. Average is about 3.5% but can vary between 1 and 4%
- Halocline: The transitional zone of salinity that changes between the ocean surface and the deep sea.
- Ocean Acidity: results from absorbing carbon dioxide. More absorption means greater acidity which means pH decreases.
What causes salinity to vary spatially?
Evaporation and river discharge depending on the area.
What are the various temperature layers in the ocean?
- Typically water on top is warmer due to light penetration.
- thermocline: transitional zone of temperature change (varies based on season and latitude)
- varies but this last layer is at 2500m everywhere and the temp is between 0 and 2oC.
What are the various vertical ocean layers based on properties of sea water?
- Epipeplagic zone: Topmost layer, absorbs 99% of sunlight.
- Mesopelagic zone: between 200 & 1000m, very little sunlight.
- Bathypelagic zone: between 1000 & 4000m, no light, found along the continental slope.
- Abyssopelagic zone: between 4000 & 6000m flat topography, also known as the abyssal plains. Starts where the continental slope ends.
- Hadal zone: between 6000 & 10,000m deepest part and the location of the deep sea trenches.
What are the features of the ocean bottom?
- Continental shelves: the shallow area around large land masses. Geologically part of the continental crust that is submerged underwater.
- Abyssal Plains: Flat submarine plain located on deep ocean floor. Located between continental shelves and ocean ridges. (deeper than 3000m)
- Mid-Oceanic ridge: Large underwater mountain or elevated area. Divides the large ocean basins. Restricts mixing of water masses at the bottom of the ocean.
- Seamounts: Isolated, flat-topped inactive volcanoes that once protruded above sea-level.
- Deep-sea trenches: Long, narrow valleys on sea floor, the deepest part of the ocean.
What is are gyres?
Large scale circulation system of ocean currents that rotate in a clockwise direction (right) in the northern hemisphere. Due to the Coriolis force.
What are ocean currents?
Large scale, continuous movement of seawater in a consistent pattern.
What are the 2 types of currents? What causes the differences?
- Surface currents: It is the movement of large scale oceanic water due to atmospheric winds.
- Deep ocean currents: Currents below surface, driven by density differences between locations. Like the pressure gradient force.
