Ch4 Flashcards
What is a Thermocline
A body of water with rapid changes in temperature with depth.
Traits of Permanent Thermocline
Occurs in tropical regions
Results in a stable water column with little mixing between warmer surface water and colder deeper water, keeping the surface water warmer.
What are 2 kinds of Thermoclines?
Permanent and Seasonal
Does a Permanent Thermocline occur in the polar regions?
Either has reduced or no permanent thermocline because the surface water does not get warm enough to warm the water further down
Traits of a Seasonal thermocline
Changes between seasons, it disappears during winter then forms again during spring.
Traits of a Seasonal thermocline II
Occurs in temperate and polar regions
The depth of the thermocline is shallow here (20-100 meters)
Why is there NO seasonal thermocline in the tropics
No seasons in the tropics
What is Barotrauma?
Damage to the body due to pressure changes
What is the Coriolis Effect?
The deflection of air and ocean currents due to the rotation of the earth
What direction does the Northern Hemisphere water go?
Right
What direction does the Southern Hemisphere water go?
Left
What effect does the Coriolis effect have on surface currents?
Causes currents to not flow parallel in the direction in which the wind pushes them
What is upwelling
The movement of nutrient rich deep cold water being sent to the surface
Two types of Upwelling
Coastal and equatorial
What does upwelling do to fisheries?
Higher levels of fish in the waters due to increased levels of phytoplankton (Fish food)
What is El Nino?
Changes in temperature distribution in the Pacific, this causes water temperature and atmosphere pressure to switch from the Western and Eastern Pacific
What is the difference between High and Low Pressure
High= Dry weather (California)
Low= Humid/Rainy weather (Philippines)
What causes El Nino?
The Trade Winds decreasing in strength
What are the effects of El Nino?
Coastal Upwelling decreases and permanent thermoclines goes deeper.
Why is El Nino called El Nino?
Because the phenomena was first noticed was around Christmas time, so it was associated with the birth of Christ
What is La Nina?
Occurs when the Trade Winds start up again with unusually stronger winds, creating higher high pressures and lower low pressures.
What is La Nada
When everything is normal in the pacific
What is Downwelling
Cold water with high density sinks down, (Conveyor belt theory)
What happens to the quality of light as you depth increases?
Red light disappears the deeper you go, blue and green travel furthest down
