Science - chapter 13
What are the two types of currents?
1. Surface currents (move water at the surface) 2. Deep currents (move water deep below the surface)
A neap tide occurs when the moon is in which positions?
1st quarter or 3rd quarter
At which two points do tidal bulges occur on Earth?
A tidal bulge happens on the side of Earth closest to the moon and on the opposite side of Earth also ("left behind" bulge).
Briefly describe where currents move water in the ocean?
At the surface of the ocean and deep below the surface
What are 3 ways to prevent beach erosin?
Barrier Islands, Sand dunes with vegetation, or man-made structures called groins
The ________ effect of Earth's __________ on the direction of winds and currents, which causes them to move in a circular pattern.
Coriolis, rotation
What are large streams of moving water that flow through the oceans?
Currents
How are currents different from waves?
Currents carry water great distances (waves carry water's energy toward shore, but the water remains in place)
What is an abnormal climate event that occurs every 2 to 7 years in the Pacific Ocean?
El Nino
T/F. The size of a wave is determined by the amount of water the waves carries.
False
T/F. Water particles in deep water move in circles when a wave passes by.
False
T/F. Water particles in deep water move randomly when a wave passes by.
False
T/F. Water particles in deep water move toward shore when a wave passes by.
False
T/F. Water particles near the surface move little if at all when a wave passes by.
False
T/F. Water particles near the surface move randomly when a wave passes by.
False
T/F. Water particles near the surface move toward shore when a wave passes by.
False
T/F. Tsunamis cause earthquakes.
False. Earthquakes can cause tsunamis.
T/F. Water is moved toward shore by a wave.
False. It changes water to energy. The energy of the wave moves toward shore, but the water itself remains in place.
T/F. Tsunamis are most common in Atlantic Ocean.
False. Pacific
T/F. Tsunamis are felt most in deep waters.
False. Shallow water.
T/F. Like surface waves, tides depend on the wind blowing.
False. Tides happen regularly no matter how the wind blows.
Why does warm water stay at the surface of the ocean?
It is less dense than cold water.
What factors affect the height of the tide in any particular location?
Landforms such as narrow bays, peninsulas and islands
How do most waves form?
Most waves form when winds blowing across the water's surface transmit their energy to the water.
Coriolis effect causes currents to curve which way in the Northern and Southern Hemispheres?
N = right S = left
Do particles floating near the water surface move closer to shore when a wave passes by?
No. They move in a circle and remain in the same place. (The closer to the surface the bigger the circle.)
Do particles in deep water move closer to shore when a wave passes by?
No. They move little if at all.
Describe the position of the sun and moon and the difference between high and low tides for a Neap Tide.
Sun and moon are at right angles and the difference between the high and low tides is least.
Describe the position of the sun and moon and the difference between high and low tides for a Spring Tide.
Sun and moon are in a straight line and the difference between the high and low tides is greatest.
___________ are currents is driven mainly by ________ and affects water to a depth of several hundred ___________.
Surface currents, winds, meters
Describe how a tidal power plant captures tidal energy.
The energy of moving tide water power turns the turbines that operate the generators that produce electricity.
What causes tides?
The interaction of the Earth, the moon, and the sun.
How does a wave change when it enters shallow water near shore?
The trough of the wave begins to touch the ocean floor and slow down. Near shore the wave height increases and the wave length decreases.
How do currents affect climate?
They move cold and warm water around the globe. A surface current warms or cools the air above it, influencing the climate of the land near the coast.
T/F. The size of a wave is determined by how far the wind blows.
True
T/F. The size of a wave is determined by how long the wind blows.
True
T/F. The size of a wave is determined by strength of the wind.
True
T/F. Tsunamis are waves.
True
T/F. Water particles in deep water move little if at all when a wave passes by.
True
T/F. Water particles near the surface move in circles when a wave passes by.
True
T/F. Waves start in the open ocean.
True
T/F. Areas of upwelling usually attract huge schools of fish.
True - because they eat the nutrients upwelling brings up from the deeper layers
T/F. Without upwelling, the surface waters of the open ocean would be very scarce in nutrients.
True - because upwelling brings up organisms, minerals and other nutrients from the deeper layers
T/F. Water on the side of Earth opposite the moon is pulled less strongly by the moon than the rest of the planet.
True - water is "left behind" to form a tidal bulge.
T/F. The sun's gravity affects Earth's tides.
True.
A giant wave caused by an earthquake on the ocean floor.
Tsunami
How do waves shape a beach?
Waves erode the shore in some places (removing sand) and build it up in others (depositing sand).
How is surf formed?
When the wave reaches a certain height, the crest of the wave topples forward and breaks onto the shore, forming surf.
When does longshore drift occur?
When water comes onto shore at an angle. The water washes along the shoreline carrying grains of sand.
T/F. Deep currents move and mix water ___________.
around the world
Salinity increases the __________ of ocean water.
buoyancy
What is the pattern of temperature and precipitation typical of an area over a long period of time?
climate
Briefly explain why cold water moves along the ocean floor as a deep current.
cold salty water is dense and it sinks
What do deep currents carry and where?
cold water from the poles toward the equator
The highest point of a wave.
crest
In the ocean, temperature ________ as depth increases.
decreases (i.e., gets colder the deeper you go)
What extends from about 1 kilometer below the surface to the ocean floor?
deep zone
Deep currents are caused by differences in ___________ of ocean water.
density
Hills of wind-blown sand covered with plants are called?
dunes
The process of breaking up rock and carrying it away is?
erosin
T/F. High tides occur more often than low tides.
false
T/F. There is more oxygen in seawater than in air.
false
T/F. Tidal energy cannot be harnassed.
false
T/F. Warm water contains more dissolved oxygen than cold water.
false
T/F. Tidal energy is nonrenewable.
false - it is renewable
T/F. Tidal energy can be used on any coast.
false - need a difference of 4 or 5 meters between high and low tides and very few places in the world have this difference.
T/F. Surface currents move in one direction in the 5 major ocean basins.
false - they move in a circular pattern
T/F. Spring tides occur only in spring.
false - they occur twice a month
T/F. High tides occur 6 hours apart.
false. They occur 12 hours and 25 minutes.
Number of waves that pass a point in a certain amount of time.
frequency
The greatest difference between high and low tides occurs when the moon is which positions?
full and new moons
Water that moves up the beach in a wave flows back out to sea due to?
gravity
A wall of rocks or concrete built outward from a beach to stop longshore drift (i.e., prevent erosin) is called a(n)?
groins / jetty
A tide in which water reaches its higest point on the beach each day?
high tide
What goes farther up the shoreline than low tide?
high tide
When the level of water on the beach reaches it highest point?
high tide
The size of a wave is determined by what 3 things?
how strong the wind is, how long the wind blows, and how far the wind blows
When ice forms near the poles, the salinity of the remaining liquid water (increases/decreases)?
increases
Movement of sand along a beach.
longshore drift
A tide in which water reaches its lowest point on the beach each day?
low tide
When the level of water on the beach reaches it lowest point?
low tide
In the ocean, temperature is _______ in the deep zone.
lowest
Do deep currents flow faster or slower than surface currents?
much more slowly
A tide with the least difference between high and low tide?
neap tide
Where is ocean salinity likely to be low?
near melting ice and near the mouth of a large river
What two gases are in ocean water that are necessary for living things?
oxygen and carbon dioxide
In the ocean, __________ is the weight of the water above pressing down.
pressure
Rapid rush of water out to sea / A rush of water that flows out from the shore through a narrow opening in sandbar.
rip current
In the ocean, pressure _________ continously as depth increases.
rises (i.e., more pressure the deeper you go)
Who needs to know the times and heights of the tides?
sailors, people who fish and people who live by the sea
What is the total amount of dissolved salts in water called?
salinity
Underwater ridge of sand.
sandbar
A tide with the greatest difference between high and low tide?
spring tide
What is an underwater vehicle built to resist pressure called?
submersible
What extends from the surface to about 200 meters below?
surface zone
What determines density?
temperature and salinity
What is the largest, most powerful surface current in the North Atlantic Ocean?
the Gulf Stream
What causes water to push up on a beach?
the energyof breaking waves
The gravity of what pulls on Earth's water creating a bulge?
the moon
The daily rise and fall of Earth's water on its coastlines are called?
tides
What does upwelling bring up from the deeper layers of the water?
tiny ocean organisms, minerals, and other nutrients
What extends from about 200 meters below the surface to about 1 kilometer below the surface?
transition zone
The lowest point of a wave.
trough
T/F. Below the surface zone, the salinity of ocean water remains fairly constant.
true
T/F. El Nino can cause rainstorms, floods and mudslides in some areas, and droughts in others.
true
T/F. El Nino causes unusual weather patterns around the world.
true
T/F. High tides occur about 12 and half hours apart.
true
T/F. High tides occur later in the west.
true
T/F. High tides occur twice a day.
true
T/F. Spring tides occur during a full moon.
true
T/F. Spring tides occur during a new moon.
true
T/F. Surface currents affect climate along the coast?
true
T/F. The energy stored in tides is potential energy.
true
T/F. Tidal energy is clean.
true
T/F. Spring tides occur twice a month.
true. they occur during the full or new moons.
What does El Nino prevent off the western coast of South America?
upwelling
What is the upward movement of cold water from the ocean depths to replace warm surface water moved away by winds?
upwelling
What part of the water is 96.5% and what part is 3.5%?
water = 96.5% dissolved salts = 3.5%
What is a vertical section of the ocean called?
water column
The movement of energy through a body of water is a(n)?
wave
Vertical distance from crest to trough.
wave height
As a wave approaches shore what happens to wave height and wave length?
wave height increases wave length decreases
Horizontal distance between crests.
wavelength
Surface currents follow the major _____ _____ of the globe. Moving in a circular pattern in the five major _________ ________.
wind patterns ocean basins
The energy and strength of a wave depend mainly on its?
wind strength
El Nino is when an unusual pattern of __________ in the _________ Pacific pushes a vast sheet of ______________ eastward toward the _________ _____________ coast
winds, western, water, South American
