Lecture 2 - Background Oceanography Flashcards
Ocean basins (definition)
Bodies of water bounded by the continents; Pacific, Atlantic, Indian, and Arctic
What is the average depth of the ocean?
3,800 meters
Continental shelf (definition)
Shallow (<200m) extensions of the continents underwater
Seamounts (definition)
Underwater mountains, 100s to 1,000s of meters high
Mid-ocean ridges (definition)
The spreading centers of tectonic plates
Trenches (definition)
Deep locations where an oceanic plate is being subducted under another plate
Continental slope (definition)
The relatively steep transition between continent and abyssal plain (200-300m)
Abyssal plain
The vast flat expanses of ocean floor (300m-600m)
What are the 5 classifications of the oceanic water column from the surface to the deepest ocean?
1) Epipelagic
2) Mesopelagic
3) Bathypelagic
4) Abyssopelagic
5) Hadalpelagic
What are the 5 classifications of the seafloor?
1) Continental shelf
2) Continental slope
3) Abyssal plain
4) Trench
Land is on average ___ than the ocean is on average deep
Lower
True or false. The continental shelf constitutes a large portion of the ocean floor?
False, shelves occupy only a few percents
The 1)___ is the largest habitat on our planet, covering about 2)___ of earth’s surface
1) deep sea
2) ~65%
Hawaii is surrounded by ___
deep ocean
What drives surface currents in the ocean?
Wind
What causes differential heating of the atmosphere?
There is more solar energy at the equator than at the poles.
What is the result of differential heating of the atmosphere?
Air heats, expands, and rises at the equator. It then radiates energy, cools, and sinks at the poles.
Hadley cell (definition)
Warm air cools before getting to the poles and sinks at ~30 degrees latitude
Polar cell (definition)
Cool air warms as it moves across earth and rises at ~60 degrees latitude
Ferrel cell (definition)
Warm air rises at ~60 degrees, but cools as it moves southward towards the equator and descends at ~30 degrees
How do atmospheric circulation cells affect atmospheric pressure and rainfall patterns?
Rising air (low pressure) gets cooler and water vapor precipitates (wet climate). Sinking air (high pressure) has little moisture left in it (dry climate).
Coriolis Effect (definition)
The eastward rotation of the earth causes moving air or water (or anything else) to be deflected to the right in the northern atmosphere (to the left in the southern hemisphere).
___ generate surface winds across the ocean
Atmospheric circulation cells
Climate (definition)
The overall average atmospheric conditions over many years
Weather (definition)
Short term variable atmospheric conditions
How does wind and the location of continents drive surface ocean currents?
Wind is the primary driver of surface currents. Trades push water west, which hits the continents and moves north, while westerlies push water back across the ocean.
Ekman Transport (definition)
The transport of water at an angle to the wind due to the Coriolis effect. Net flow of water is to the right of the wind direction in the northern hemisphere.
Gyres (definition)
Large areas defined by the currents flowing in a circular pattern
5 main oceanic gyres
1) Indian
2) North Pacific
3) South Pacific
4) North Atlantic
5) South Atlantic
