Chapter 11: The Oceans Flashcards
What determines wave height?
How fast, long and how far the winds has been blowing them. They’re height ranges from 2m to 5m
What are calm waves called?
Swells
How do you measure the height of a wave?
From trough to crest
How do you measure the wavelength of a wave?
Crest to Crest
Trough to Trough
Frequency
The time it takes for a wave to pass a certain point.
What creates waves?
Wind*
How are some of the highest waves created?
Earthquakes, Landslides and under water volcanoes
How do the particles in a wave move?
In a circular motion, in the direction of the wave.
What happens as a wave approaches shore?
The top continues at the same speed but the bottom slows down due to friction
What is a breaker?
In a body of water a wave that breaks or collapses into foam when it reaches shallow water or the beach. Wave length shortens during this process.
Describe the impact of ocean waves (breakers) on a bay and headland
Most of the energy is concentrated on the headlands applying a lot less force on the bay.
How is sand formed?
Erosion causes rock to break down into what we call sand, on gentler slopes it stays.
What kind of waves erode a beach?
Winter waves
What kind of waves add sediment to the beach?
Summer waves
What is a breakwater and why is it called that?
A breakwater is a structure set up to break waves so they have less of an impact on the shore and leave sand beaches sandy.
What controls tides movements?
The moon
What are the largest tides called?
Spring tides, this is when the sun and moon are in line
What are low tides called?
Neap tides, when the sun and moon are at a right angle to each other.
When the spring tide is high where is the extra water coming from?
The other side of the ocean
What is the interval between one tide and the next?
6hrs and 13 mins
What is the largest ecosystem in the world?
Oceans
Below what is the ocean pitch black?
100 metres
What controls the shape and formation of the ocean floor?
The shifting of tectonic plates
What are tectonic plates?
Part of the earth’s outer crust, continents sit on them. They cause earthquakes volcanos etc.
What ocean is getting wider?
The Atlantic
What are the newest part of the ocean called? What are they made up of?
Mid-Ocean ridges, they are made up of quick hardening molten lava.
What are underwater mountains called? Where are they the most common?
Seamounts
The Pacific Ocean
What are underwater canyon called?
Trenches
What are the huge expanses of open space on the ocean floor called?
Abyssal Plains
What is the continental shelf?
The gradually sloping area between a sea coast and the edge of the ocean basin
What is a continental slope?
A steep slope dividing a continental shelf from an ocean basin
What is the chemical name for sea salt?
Sodium Chloride
Where does the minerals and materials in the ocean come from?
Rivers
What is a current?
It is like a massive river in the water
What drive currents?
Currents are driven by ocean winds, they are caused by constant prevailing wind patterns.
How do prevailing wind patterns move?
Clockwise above the equator and counterclockwise below the equator
What are three factors affecting prevailing wind patterns?
Uneven heating in the atmosphere
Rotation of the earth
Continents
What creates wind?
Differences in air pressure produced by uneven heating in the atmosphere
What is the Coriolis effect?
A deflection (bending) of moving air and water currents; produced by the earth’s rotation
What direction do trade winds move?
East to west
What direction do westerly wind move?
West to east
How do continents impact ocean currents?
Moving continents are forced to turn when they meet a solid surface (continents)
What are the three temperature zones in the ocean?
Mixed layer
Thermocline
Deep water
What are density currents?
a mass of cold water flowing beneath the ocean surface; the water is often more saline (salty) than surrounding water and often contains a significant amount of sediment.
What is an upwelling?
When cold water rises to the surface to replace water blown to different areas.
