What happens to a rubber duckie sitting on the water surface when waves pass by?
It moves in a nearly circular motion, always returning to the same spot
If you were a submarine commander and wanted to go deep enough that your ship would not feel the effect of 300-foot (91-meter) wavelength storm waves, how deep would you have to dive?
150 feet
Why do tsunami waves always behave as shallow water waves?
Their wavelengths are long enough that anywhere in the ocean the water depth is less than L/20
What are the primary factors that determine wave height?
Wind speed, length of time wind blows in one direction, and fetch
Which of the following mechanisms is NOT a cause for tsunamis?
Lunar tides
If you have two deep-water waves with periods of 5 and 10 seconds, what can you say about their speeds?
The longer period wave will have greater speed
Where would it be most likely that you would find internal waves in the ocean?
At the pycnocline
Why does wave height increase in shallow water?
Wave orbital motion is constricted by the sea bottom
Most internal waves are created by __________.
energy being released in the ocean
All of the following are characteristics of waves except __________.
shoals
Wave reflection is explained by which of the following?
The bouncing back of wave energy caused by waves striking a hard barrier
If the Moon had an iron core, what would happen to lunar tides?
The tides would become larger because the Moon is more massive
The lunar tidal bulge has a period of 12 hours and 25 minutes, but the solar tidal bulge period is 12 hours. Why the difference?
The Moon moves around Earth in its orbit
If you are in a boat in an estuary, when will tidal currents going out to sea be strongest?
Halfway between high tide and low tide
Why are spring tides highest when the Moon is near perigee?
The Moon is closer to the Earth, so gravitational force is greater
If a point on the coast experiences a semi-diurnal tide, what does the daily tide record show?
Two nearly equal high tides and two nearly equal low tides each day
The tide is sweeping across the ocean toward land. The continental shelf is significantly wider at one location than another farther down the coast. What will happen to the tide at the location where the shelf is wider?
The tide will be retarded
In the absence of friction (and other complicating factors) where would the maximum ideal lunar tide occur?
At two points, directly beneath and opposite the Moon. The Moon and Sun are lined up.
Tides would be easy to predict if __________.
Earth were a uniform sphere covered with an ocean of uniform depth
All of the following are types of tidal patterns except __________.
triurnal tidal patterns
Tidal power can be harnessed by __________.
(A and C) Trapping water behind coastal barriers in bays and estuaries and allowing tidal currents to pass through narrow channels to turn turbines.
If you look at beach sand under a magnifying glass, what do you see?
Whatever sand-sized particles are available from local rivers and streams
In winter, sand from some beaches disappears. Where does it go?
Winter wave action moves the sand offshore into bars, located just below the wave base
Longshore current generally flows in which direction(s) along the coasts of the United States?
Southward along both coasts
Which of the following mechanisms of sea level change is NOT eustatic?
Glacial isostatic subsidence and rebound
If you are at the beach and blunder into a rip current, how do you get out?
Swim perpendicular to the current until you are out (usually parallel to shore)
During a hurricane, which of the following is UNLIKELY to occur on a barrier island?
There will be little change in size and shape to the island
What would happen to a river delta if damming reduced the amount of sediment in the river?
The delta would erode and subside below sea level
What would happen to longshore transport along the coast if rivers on the coast were dammed, trapping sand behind the dams?
The longshore transport would become less
What is the purpose of hard stabilization?
To protect a coast from erosion
What is not a main component of a beach compartment?
The biosphere's use of the beach as its environment
What is an alternative to hard stabilization?
Beach nourishment
What is the defining characteristic of an estuary?
A partly enclosed body of water in which salinity is dictated by mixing of fresh water runoff and ocean water
What is the most common type of estuary on the U.S. East and Gulf coasts?
Coastal plain estuary (a.k.a. drowned river valley)
In general, what is the most common thing to happen when fresh water runoff meets ocean water in an estuary?
Fresh water forms a layer on top of a layer of salt water at the bottom
What causes the basal waters in some estuaries to become anoxic?
Formation of a strong pycnocline limits circulation and decay of sinking organic matter promotes respiration, depleting bottom waters of oxygen
What makes a body of water a marginal sea?
It is a semi-isolated section of the ocean with restricted circulation from the main ocean
What would happen to the Mediterranean Sea if the Gibraltar Sill closed it off from the Atlantic Ocean?
It would dry out nearly completely
Galveston Bay (South Texas) has two rivers that empty into it (Trinity and San Jacinto rivers). It also has two barrier islands (Galveston Island and Bolivar Peninsula) that separate it from the sea. What type of estuary do you think it is?
Coastal plain
Which of the following would you classify as a pollutant?
Sewage
A test that determines the concentration of a pollutant that causes 50% mortality among a specific group of organisms is an example of what?
Environmental Bioassay
When animals eat other animals, some pollutants move up food chain and become concentrated in the tissues of larger animals. What is this process called?
Biomagnification
Which of the following is an example of a non-point-source pollution.
All of the above