Abyssal Plain- A feature of the deep-sea floor; the flattest of all earth’s surface areas. (Pg 517)
Ex. Abyssal plains the composed of sediments, most of which came from continents.
Barrier Island- Sandbars that form on coasts with straight shorelines; not attached to the shore
(Pg 352)
Ex. Since barrier islands are not attached to the shore, they run parallel to it at some distance
offshore.
Continental Shelf- Part of the continent that extends from the shoreline out to the continental
slope. (Pg 514)
Ex. Continental shelves tend to be very flat and their widths vary.
Continental Slope- Begins at the shelf edge, where water depth begins to increase rapidly.
(Pg 514)
Ex. Sediments tend to build up temporarily on the continental slope; eventually they become
unstable and tumble downward to form the continental rise.
Continental Rise- Descends gradually from the continental slope to the ocean floor at between
four and eight miles per kilometer. (Pg 514)
Ex. The continental rise connects the continental slope and the abyssal plain.
Echo Sounding- A technique used to find the distance to the ocean floor. (Pg 510)
Ex. Echo sounding works by sending a signal through the water to the sea floor, seeing how
long it takes to reach the bottom and then echo back to the ship.
Climate- An area’s long-term pattern of weather (Pg 466)
Ex. Climate includes many characteristics including how hot the summers are, how cold the
winters are, and how much precipitation falls at different times of the year.
Oceanography- The scientific study of the ocean using chemistry, biology, physics, geology, and
other sciences. (Pg 490)
Ex. Studying the habitat in which dolphins live in would be considered oceanography.
Apogee- When the moon is farthest from earth. (Pg 542)
Ex. When the moon is at apogee, the tidal effect is less.
Crest- A wave’s high point. (Pg 344)
Ex. The opposite of a crest is a trough, which is a wave’s low point.
Guyot- Flat-topped sea mounts. (Pg 520)
Ex. When a seamount gets extreme wave action, the top will flatten over time.
Island- A piece of land completely surrounded by water, formed by volcanic action and a midocean ridge. (Pg 177, 518)
Ex. Volcanic island chains are called island arcs.
Lagoon- Sandbars usually protect the water behind them from strong winds and waves; the
protected areas are lagoons. (Pg 351)
Ex. If the Lagoon fills with sediment, it becomes a salt marsh.
Longshore Current- An ocean current that slows parallel to the shoreline.
Ex. Along irregular shorelines, longshore currents carry away most of the sand and pebbles
eroded from the headlands.
Mid-ocean Ridge- A long chain of mountains with a central rift valley that is located along a
divergent boundary on the ocean floor. (Pg 174)
Ex. Mid-ocean ridges form at divergent plate boundaries where two lithospheric plates are
moving apart.
Upwelling- A vertical current; occurs when cold deep water comes to the surface. (Pg 538)
Ex. Although upwelling can occur anywhere, it is most common on the western sides of
continents.
Estuary- the tidal mouth of a large river, where the tide meets the stream.
Ex. Estuaries are often referred to as “Delta”, such as the Nile Delta.
Tides- The periodic rise and fall of the ocean surface due to the gravitational pulls of the moon
and sun. (Pg 541)
Ex. The phases of the moon have a great effect on the tides that occur in the ocean.
Salinity- A measure of the dissolved salts in water. (Pg 495)
Ex. You can measure the salinity of a sample of seawater in a beaker by evaporating the water
and weighing the salt that remains at the bottom of the beaker.
Salt Marsh- As time passes, lagoons may fill with sediment and become salt marshes. (Pg 351)
Ex. Gulf Coast Salt Marshes are the most commonly known/visited salt marshes.
Seamount- Cone shaped mountain peaks that rise high above the deep ocean floor. (Pg 520)
Ex. Seamounts are typically found in clusters and rows.
Spit- A narrow point of land that extends to a body of water formed by ocean waves. (Pg 351)
Ex. Waves and crosscurrents may curve the end of a spit and then it is referred to as a “hook”
instead of a spit.
Trough- A wave’s low point. (Pg 344)
Ex. The opposite of a trough is a crest, which is a wave’s high point.
El Niño- A warm surface current in the Pacific Ocean. (Pg 485)
Ex. Scientists still do not exactly understand what causes El Niño in some years and not in
others, or just how it causes major changes in the world’s weather.
Current- Any continuous flow of water along a broad path in the ocean. (Pg 532)
Ex. Currents can flow at the surface or far below it.
Climate Controls- The set of conditions in which the climate of a location depends on. (Pg 467)
Ex. Some of the climate controls are latitude, elevation, nearby water, ocean currents,
topography, prevailing winds and vegetation.
Perigee- When the moon is closest to earth. (Pg 542)
Ex. When the moon is at perigee, the tidal effect is greater, especially if it occurs during the new
or full moon phases.
Questions
Answers
Page #’s
1) What percentage of earth’s
surface is covered by water?
More than 70 percent
490
2) List 3 scientific devices
oceanographers use in their
research
JOIDES (four-story underwater laboratory)
Alvin (mini submarine)
Moored buoys
490
3) Describe 3 ways that polarity of
water molecules affects the
behavior of water
-strong attraction
-high boiling point
-crystal lattice forms when frozen
493
4) Compare the boiling and freezing
points of pure water with the
boiling and freezing points of salt
water
The levels of salt in seawater make it 2-3
percent more dense than pure water; The
boiling point increases as salt
concentrations rise and the freezing point
decreases
494
5) Describe 2 ways to measure
salinity
-Evaporating the water and weighing the
salt that remains; find the ratio of the
mass of salt to the mass of the water
-Measuring the electrical conductivity of
seawater (psu)
Increase- Hot, dry area; Frozen seawater
Decrease- Minerals precipitate out and
settle to the ocean bottom as sediment
495
Chapter 22
6) Describe one factor that causes
salinity to increase and one
factor that causes salinity to
decrease
496
Questions
Answers
Page #’s
1) What information can scientists
learn from a sediment core?
They can examine the different layers of
the ocean floor
511
2) How do satellites determine the
terrain of the ocean floor?
Signals bounce off the ocean surface. The
ocean surface varies depending what lies
beneath it; it is slightly higher over
undersea mountains and slightly lower
over undersea trenches
511
3) Compare and contrast active and
passive continental margins
Active- oceanic plate is sliding beneath, or 515
subducting under, the continental plate
Passive- Not located at plate boundaries;
no ocean trenches or rugged coastal
mountains
Both- lie in relation to a subduction zone
or transform fault
They are covered in sediments that have
517
been washed off the surface of
continents caused by turbidity currents
Chapter 23
4) Why are abyssal plains so flat?
5) What actions occur along ocean
ridges?
Transform vaults separate them into
pieces; with the rugged terrain around
them, they make up fracture zones
520
Questions
Answers
Page #’s
1) What is the primary cause of
surface currents?
The wind
532
2) Would you expect the water off
the Pacific coast of the US to be
warmer or colder than water off
the Atlantic coast at the same
latitude? Explain your reasoning
3) Why are density currents so
important to marine life in the
deep ocean?
Colder- there are cool currents traveling
near the west coast and there are warm
currents near what seems to be the east
coast of the US
532-533
They retain oxygen absorbed at the
surface layer; such deep currents are the
only source of oxygen for deep-sea life
536
4) Where does the densest water in
the ocean come from? Explain
why
Polar regions, due to intense cooling and
freezing that occurs (water takes up less
space because it is cooled; molecules get
packed together)
537
5) Describe 2 causes of upwelling
1- Prevailing winds blow among the
coastline towards the equator
2- Two major wind belts blow on either
side of the upwelling region
539
6) What are tides?
The periodic rise and fall of the ocean
surface due to the gravitational pulls of
the moon and sun.
541
7) Explain the difference between
spring and neap tides
Spring- alignment of the earth, sun and
moon occur at the times of a new/full
moon (high/low tides are extreme)
Neap- not aligned, occur during quarter
phases (high/low tides are not extreme)
542
8) How does the shape of an inlet
affect its tidal range?
If it is a V-shape, the water piles up at the
narrow end. When the shoreline is much
broader than its mouth, the water
spreads out over the shoreline
543
Chapter 24
Questions
Answers
Page #’s
1) Why doesn’t average
temperature give a complete
picture of climate?
It only describes how hot or cold a
climate is; doesn’t give variations of the
weather
466
2) Choose 3 of the climate controls
listed on page 467, and describe
how they affect the climate
where we live
Prevailing winds- determine whether air
masses from a hot/cold/wet/dry region
Elevation- generally colder and drier the
higher the altitude (mountains)
Nearby water- coastal areas tend to
have mild climates and precipitation
(Virginia is in the east coast; VA beach)
Latitude- colder towards the poles; midlatitudes have precipitation (Like in VA)
Vegetation- affects insolation and how
quickly air heats/cools; releases water
vapor through transpiration (Lots of
vegetation in VA, therefore its hot/wet)
467
3) In what way do earth’s motions
change over time?
-Shape of the Earth’s orbit varies with a
period of about 100,000 years
-The tilt of Earth’s axis varies between
22.1 and 24.5 degrees with a period of
41,000 years
-Earth’s axis of rotation wobbles with a
period of about 23,000
474-475
4) Explain how sunspots may affect
climate
The amount of energy given off by the
sun increases slightly when the number
of sunspots increases; if the sun emits
more energy, there is more energy
available to reach the earth.
475
5) Describe 3 ways scientists learn
about past climate changes
Sea-floor sediments, glacier samples and
tree rings
476
Chapter 21