Study Guide for Chapter 10 Lessons 4, 5, and 6---Test Date Tuesday, February 13th!!!!!!

Study Guide – Chapter 10

Lessons 4, 5, 6,

What 3 ways does the water in Earth’s oceans vary?

1)     Salinity

2)     Temperature

3)     Depth

What is salinity?

Answer:  Salinity is the total amount of dissolved salts in a sample of water.

At what temperature does salt water freeze?

Answer:  -1.9 degrees Celcius

At what temperature does fresh water freeze?

Answer:  0 degrees Celcius

True or False???

As you descend through the ocean, the water temperature decreases.   TRUE!!!!!

What is sonar?

Answer:  Sonar (Sound Navigation Ranging) uses sound waves to calculate the distance to an object.

What are six major ocean floor features?

1)     trench—a long, deep valley on the ocean floor through which old ocean floor sinks back towards the mantle

2)     continental slope—the steep edge of the continental shelf

3)     continental shelf--a gently sloping, shallow area that extends outward from the edge of each continent

4)     abyssal plain—a broad area covered with thick layers of mud and silt—it is usually a smooth, nearly flat region of the ocean

5)     mid-ocean ridges—long chains of mountains on the ocean floors

6)     seamount--a volcanic mountain rising from the ocean floor that doesn’t reach the surface

True or False???

Most waves form when winds blowing across the water’s surface transmit their energy to the water.   TRUE!!!!!

What is a wave?

Answer:  A wave is the movement of energy through a body of water.

What is the highest part of a wave?

Answer:  The crest is the highest part of a wave.

What is a wavelength?

Answer:  A wavelength is the horizontal distance between crests.

What is the ‘frequency’ of a wave?

Answer:  The number of waves that pass a point in a certain amount of time.

What is wave height?

Answer:  The vertical distance from the crest to the trough is the wave height.

What is the lowest part of a wave called?

Answer:  The lowest part of a wave is called a trough.

True or False?????

Near shore, wave height increases and wavelength decreases.   TRUE!!!!!

What is a tsunami?

Answer:  A tsunami is a type of wave that is usually caused by an earthquake beneath the ocean floor.

Why do waves change as they approach shore?

Answer:  The waves become shallower.  The bottoms of the waves begin to touch the sloping ocean floor.  Friction between the ocean floor and the water causes the waves to slow down.  As the speed of the waves decreases, their shapes change.

True or False?????

Waves usually roll toward shore at an angle.   TRUE!!!!!

What is a longshore drift?

Answer:  A longshore drift is the movement of sand along the beach.  As the waves slow down, they deposit the sand they are carrying on the shallow, underwater slope, forming a long ridge called a sandbar.

What is a rip current?

Answer:  A rip current is a rush of water that flows rapidly back to sea through a narrow opening in a sandbar.

How do waves shape a beach?

Answer:  Waves shape a beach by eroding the shore in some places and building it up in others.

What is a groin?

Answer:  A groin is a wall of rocks or concrete used to reduce beach erosion.

What are surface currents driven by?

Answer:  Surface currents are mainly driven by wind.

What is the Coriolis Effect?

Answer:  The Coriolis Effect is caused by the Earth’s rotation causing an effect on the direction of winds and currents. 

How do currents in the Northern Hemisphere move when effected by the Coriolis Effect?

Answer:  The currents curve clockwise.

How do currents in the Southern Hemisphere move when effected by the Coriolis Effect?

Answer:  The currents curve counterclockwise.

What is the largest and most powerful surface current in the North Atlantic Ocean?

Answer:  The Gulf Stream is the largest and most powerful surface current in the North Atlantic Ocean.

What is climate?

Answer:  Climate is the pattern of temperature and precipitation typical of an area over a long period of time.

What is El Niño?

Answer:  El Niño is a climate event that occurs every two to seven years in the Pacific Ocean.  It causes shifts in weather patterns due to an unusual pattern of winds forming over the western Pacific.

What is La Niña?

Answer:  La Niña  is a climate event that occurs when surface waters in the eastern Pacific are colder than normal.  It usually brings colder than normal winters and greater precipitation to the Pacific Northwest and north central United States.

True or False?????

Cold water is more dense than warm water.   TRUE!!!!!

What causes deep currents?

Answer:  Deep currents are caused by differences in the density of ocean water.

True or False?????

Deep currents move and mix water around the world.  They carry cold water from the poles toward the equator.    TRUE!!!!!

Students Create Fabulous Posters of "The Water Cycle"

Chapter 10 Lessons 1, 2, and 3 Scheduled and "The Water Cycle" Poster Due on Monday, January 22nd!

Hello Parents!

We have jumped forward to Chapter 10 covering water and its effect on Earth/many uses. This is a VERY LONG chapter. I will be dividing it in half for our tests. The first test will be on Tuesday, January 30th, and it will cover Lessons 1, 2, and 3. I gave your children a study guide yesterday. They should begin studying now (10-15 minutes each night). We just started Lesson 1 yesterday, and will be finishing the lesson today. I will be sending home a rubric and a piece of white poster board with your child today. These items are for a project your child will need to complete between now and Monday. It is due on Monday (January 22nd). Your children must know how The Water Cycle works and be able to draw it and describe the process. I will be drawing a sample on the white board today for the children, and will be sending home a handout with the cycle on it. There is also a diagram in their science text. The rubric is very specific, and if everything is completed on it, it is worth 110 points (a test grade). On Monday, the children will be presenting their posters, so it is important that they understand the process fully. If you have questions, feel free to contact me. Below are the study guide, a copy of the rubric, and a copy of the diagram. Please don't rely totally on the diagram. Your child should use the diagram in the book, as well. Thank you! Beth Stafford

Study Guide - Chapter 10-Water

Lessons 1, 2, and 3

Why is water important?

Answer: Water makes up nearly two-thirds of your body's mass. That water is necessary to keep your body functioning.

What body processes does water help with?

1-breaking down food

2-grow

3-reproduce

4-get and use materials they need from their environments

What is a habitat?

Answer: A habitat is the place where a living thing lives and obtains all the things it needs to survive.

True or False?

Most of Earth's surface water - nearly 97 percent - is salt water found in oceans. Only 3 percent is fresh water. TRUE!!!!!

Of the 3 percent of fresh water, how much is frozen in huge masses of ice near the North and South Poles?

Answer: 2/3 is frozen

Which is the largest ocean?

Answer: The Pacific Ocean is the largest, covering an area greater than all the land on Earth.

What is groundwater?

Answer: Groundwater is the water that fills the cracks and spaces in underground soil and rock layers.

True or False?

Far more fresh water is located underground than in all of Earth's rivers and lakes. TRUE!!!!!

What are the four main sources of fresh water on Earth?

Answer: 1) ice, 2) rivers, 3) lakes, and 4) groundwater

What are the major steps of the water cycle?

Answer:

Evaporation - is the process by which molecules at the surface of a liquid absorb enough energy to change to a gaseous state.

Transpiration - Water is given off through the leaves as water vapor.

Condensation - is the change in state from a gas to a liquid.

Precipitation - Any form of water that falls from clouds and reaches Earth's surface as rain, snow, sleet, or hail.

What is a tributary?

Answer: The streams and smaller rivers that feed into a main river are called tributaries.

True or False?????

Tributaries flow downward toward the main river, pulled by the force of gravity. TRUE!!!

What is a watershed?

Answer: The land area that supplies water to a river system is called a watershed.

True or False?????

Watersheds are sometimes known as drainage basins. TRUE!!!

What is a divide?

Answer: A ridge of land that separates one watershed from another is called a divide.

What is the longest divide in North America?

Answer: The Great Divide (also called the Continental Divide) is the longest divide in North America.

What makes a lake or pond different from a river?

Answer: Unlike streams and rivers, ponds and lakes contain still water.

Where does pond and lake water come from?

Answer: Ponds and lakes form when water collects in hollows and low-lying areas of land.

Name ways that lakes can be formed.

Depressions created by ice sheets can form lakes.

Movements of Earth's crust that formed long, deep valleys called rift valleys.

Volcanoes can form lakes-lava and mud from the volcano block a river.

Lakes can also be formed in the empty craters of volcanoes.

People can create a lake by building a dam.

What is a lake that stores water for human use called?

Answer: A lake that stores water for human use is called a reservoir.

Which is usually deeper, a lake or a pond?

Answer: a lake

What can cause lakes to disappear?

Answer: Natural processes and human activities can cause lakes to disappear.

What is eutrophication?

Answer: Eutrophication is the buildup over time of nutrients in freshwater lakes and ponds that leads to an increase in the growth of algae.

What is a water table?

Answer: The water table is the top of the saturated layer.

What are permeable materials?

Answer: Rock and soil that have large and connected pores (sand and gravel) allow water to pass through. These are permeable.

What are impermeable materials?

Answer: Materials that have few or no pores or cracks, or the pores are very small or unconnected, are impermeable (clay and granite) or will NOT allow water to pass through.

Explain what a water zone is.

Answer: Water from precipitation soaks down through permeable rock and soil layers. These layers contain air as well as water, so they are not saturated, or filled, with water. The top layer is thus called the unsaturated zone. At some depth, the water reaches a level where the pores in the ground are saturated with water. This is called the saturated zone. THE TOP OF THE SATURATED ZONE IS THE WATER TABLE!

What is an aquifer?

Answer: An aquifer is any underground layer of permeable rock or sediment that holds water and allows it to flow.

What are three ways people can get water from an aquifer?

Springs-Springs are formed as groundwater bubbles or flows out of cracks in the rock.

Wells-People bring groundwater to the surface for drinking and other everyday use by drilling a well below the water table.

Artesian wells-Water rises on its own because of pressure within an aquifer.

"The Water Cycle"

Rubric

Title: The title of your poster should be

written and centered at the top of your poster.

Points Possible: 5

The poster should correctly contain all parts of

The Water Cycle, and each part should be neatly and clearly illustrated (drawn and colored).

Points Possible: 50

*evaporation

*condensation

*precipitation

*transpiration

*runoff

Each part of The Water Cycle should be defined on the poster. Points Possible: 25

The poster should be neat, organized, colorful, and creative. Points Possible: 15

All wording should be spelled correctly. Definitions should be written in complete sentences with proper grammar and punctuation.

Points Possible: 15

Total Points Possible: 110

Chapter 6 Study Guide and Test Date

Hello Parents!

Happy New Year 2018!!!! I hope your Christmas breaks were happy and restful! I am here at school today planning for the next couple of weeks, and am confident that we will be ready to test over Chapter 6 by Friday, January 12th. While we will just begin the chapter tomorrow, it is very short!

Please begin working with your children (15 minutes each day) in preparation for the test. If you have any questions, feel free to let me know! The Study Guide is below, and your children will be given a hard copy tomorrow.

Blessings this joyous New Year,

Beth Stafford

Chapter 6

'Weathering and Soil'

Study Guide

What is uniformitarianism?

Answer: Uniformitarianism is the principle that states that the geologic processes that operate today also operated in the past. Example: Ancient landforms formed through the same processed observed by scientists today.

What two things break down rocks?

Answer: erosion and weathering

What is erosion?

Answer: Erosion is the process of wearing down and carrying away rocks.

What is weathering?

Answer: Weathering is the process that breaks down rock and other substances from heat, cold, water, ice, and gases.

What are the two types of weathering?

Answer: mechanical weathering and chemical weathering

What is mechanical weathering?

Answer: The type of weathering in which rock is physically broken into smaller pieces is called mechanical weathering.

What are the natural agents of mechanical weathering?

Answer:

freezing and thawing

release of pressure

plant growth

actions of animals

abrasion

What is abrasion?

Answer: Abrasion is the wearing away of rock by rock particles carried by water, ice, wind, or gravity.

What is chemical weathering?

Answer: Chemical weathering also breaks down rocks, but it does it through chemical changes.

What are the agents of chemical weathering?

Answer:

water

oxygen

carbon dioxide

living organisms

acid rain

What two important factors determine the rate at which weathering occurs?

Answer:

the type of rock

the climate

What does permeable mean?

Answer: Permeable means that a material is full of tiny, connected air spaces that allow water to seep through it.

True or False?

Chemical reactions occur faster at higher temperatures. TRUE!!!

Chemical weathering occurs more quickly where the climate is both hot and wet!

What is soil?

Answer: Soil is a mixture of rock particles, minerals, decayed organic material, water, and air.

What is bedrock?

Answer: Bedrock is the solid layer of rock beneath the soil.

What is humus?

Answer: Humus is a dark-colored substance that forms as plant and animal remains decay.

What is fertility of soil?

Answer: Fertility of soil is a measure of how well the soil supports plant growth.

True or False?

Soil that is rich in humus generally has high fertility. TRUE!!!

Sandy soil containing little humus has low fertility. TRUE!!!

What is the best soil for growing most plants?

Answer: loam

What is pH scale?

Answer: A pH scale is a range of values used to indicate how acidic or basic a substance is; expresses the concentration of hydrogen ions in a solution.

A substance with a:

pH less than 4 is STRONGLY ACIDIC!

pH of 7 is NEITHER acidic nor basic (Pure water is an example of this!)

pH greater than 10 is strongly basic

True or False?

Most garden plants grow best in soil with a pH between 6 and 7.5. TRUE!!!

How does soil form?

Answer: Soil forms as rock is broken down by weathering and mixes with other materials on the surface. Soil develops in layers called horizons. A soil horizon is a layer of soil that differs in color, texture, and composition from the layers above or below it.

What is a C Horizon?

Answer: A C Horizon forms as bedrock begins to weather by breaking up into small particles.

What is a B Horizon?

Answer: A B Horizon (subsoil) usually consists of clay and other particles of rock, but little humus. It forms as rainwater washes these materials down from the A Horizon.

What is an A Horizon?

Answer: An A Horizon is made up of topsoil, a crumbly, dark brown soil that is a mixture of humus, clay, and other minerals. Topsoil forms as plants add organic material to the soil, and plant roots weather pieces of rock.

What are decomposers?

Answer: Decomposers are the organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals.

What organisms are considered decomposers?

fungi (like mushrooms)

bacteria

worms

How do animals affect soil?

Answer: mammals such as mice, moles, and prairie dogs break up hard, compacted soil and mix humus with it. Animal wastes contribute nutrients to the soil as well.

What is a natural resource?

Answer: A natural resource is anything in the environment that humans use.

What is one of nature's most valuable natural resources?

Answer: soil

What are two ways that the value of soil is reduced?

loss of fertility through a loss of moisture and nutrients

loss of topsoil due to water and wind erosion

What is soil conservation?

Answer: It is the management of soil to limit its destruction.

Name three ways soil can be conserved.

Answer:

contour plowing---Farmers plow their fields along the curves of a slope instead of in straight rows. This method helps slow the runoff of excess rainfall and prevents it from washing the soil away.

conservation plowing---Dead weeds and stalks of the previous year's crop are plowed into the ground to help return soil nutrients, retain moisture, and hold soil in place.

crop rotation-A farmer plants different crops in a field each year.

Chapter 5 Test on December 19th, Tuesday -- Study Guide Below

Chapter 5 Study Guide

Volcanoes

Where do volcanic belts form?

Answer:  Volcanic belts form along the boundaries of Earth’s plates.

What is the difference between magma and lava?

Answer:  Magma is a molten mixture of rock-forming substances, gases, and water from the mantle.  When magma reaches the SURFACE of the Earth, it is called lava. 

True or False---

After magma and lava cool, they form solid rock.   TRUE!!!!

What is the Ring of Fire?

Answer:  It is one major belt of volcanoes that includes the many volcanoes that rim the Pacific Ocean including those along the coasts of North and South America and those in Japan and the Phillipines.

What is a string of islands created by volcanoes formed from converging boundaries?

Answer:  an island arc

What is another way that volcanoes can form other than along plate boundaries?

Answer:  A volcano forms above a HOT SPOT (an area where material from deep within Earth’s mantle rises through the crust and melts to form magma). 

List and explain the parts of a volcano (a system of passageways through which magma moves).

1.     Magma chamber-All volcanoes have a pocket of magma beneath the surface.  Beneath a volcano, magma collects in a magma chamber.  During an eruption, the magma forces its way through one or more cracks in Earth’s crust.

2.     Pipe-Magma moves through a pipe, a long tube that extends from Earth’s crust up through the top of the volcano, connecting the magma chamber to Earth’s surface.

3.     Vent-Molten rock and gas leave the volcano through an opening called a vent.  Some volcanoes have a single central vent at the top.  But volcanoes often have vents on the sides also.

4.     Lava flow-a lava flow is the spread of lava as it pours out of a vent.

5.     Crater-a crater is a bowl-shaped area that may form at the top of a volcano around the central vent.

True or False---

When a volcano erupts, the force of the expanding gases pushes magma from the magma chamber through the pipe until it flows or explodes out of the vent.  TRUE!!!!

What is silica?

Answer:  Silica is a material found in magma that forms from the elements oxygen and silicon.

Name two types of volcanic eruptions:

1.     Quiet eruptions-a volcano erupts quietly if its magma is hot or low in silica.  Hot, low silica is thin and runny and flows easily.  The gases in the magma bubble out gently.  Low-silica lava oozes quietly from the vent and can flow for many kilometers.

Quiet eruptions can produce different types of lava:

Pahoehoe (pah HOH ee hoh ee) forms from fast-moving, hot lava that is thin and runny.  The surface of pahoehoe looks like a solid mass of ropelike coils.

Aa (AH ah) forms from lava that is cooler and thicker.  The lava that aa forms from is also slower-moving.  It has a rough surface consisting of jagged lava chunks.

Example of a quiet eruption: the Hawaiian Islands

2.     Explosive eruptions-a volcano erupts explosively if its magma is high in silica.  High-silica magma is thick and sticky.  It can build up in the volcano’s pipe, plugging it like a cork in a bottle.  Dissolved gases cannot escape from the thick magma.  The trapped gases build up pressure until they explode.  Lava is powerfully thrown into the air where it breaks into fragments of different sizes.  The smallest pieces are volcanic ash, and the larger pieces, called bombs, may range from the size of a golf ball to the size of a car.

Example of an explosive eruption:  Mount St. Helens in Washington State (1980)

What is a pyroclastic flow?

Answer:  It is a mixture of hot gases, ash, cinders, and bombs that flow down the sides of a volcano when it erupts explosively.  Landslides of mud, melted snow, and rock can also form from an explosive eruption.

What are the stages of volcanic activity?

Answer: 

1-     Dormant—a sleeping volcano that scientists expect to awaken in the future and become active.

2-     Extinct---a dead volcano that is unlikely to ever erupt again.

3-     Active---a live volcano is one that is erupting, or has shown signs that it may erupt, in the near future.

What is a caldera?

Answer:  A caldera is a huge hole left by the collapse of volcanoes.

What landforms do VOLCANIC ERUPTIONS create?

Answer:

1-     Calderas—large holes at the top of volcanoes formed when the roof of a volcano’s magma chamber collapses.

2-     Shield Volcanoes---wide, gently sloping mountains made of layers of lava and formed by quiet eruptions.

Example of a shield volcano:  Mauna Loa in Hawaii

3-     Cinder Cone Volcanoes---steep, cone-shaped hills or small mountains made of volcanic ash, cinders, and bombs piled up around a volcano’s opening.

Example of a cinder cone volcano:  Paricutín in Mexico

4.     Composite Volcanoes---tall, cone-shaped mountains in which layers of lava alternate with layers of ash and other volcanic materials.

Example of a composite volcano:  Mount Fuji in Japan & Mount St. Helens in Washington State

5.     Lava Plateaus---thin, runny lava flows out of several long cracks in an area and travels before cooling and solidifying.  After millions of years, repeated floods of lava can form high, level plateaus.  These are called lava plateaus.

Example of a lava plateau:  Columbia Plateau—covers parts of Washington State, Oregon, and Idaho

What landforms does MAGMA create?

*Sometimes magma cools and hardens into rock before reaching the surface.  Over time, forces such as flowing water, ice, or wind may strip away the layers above the hardened magma and expose it.

1.     Volcanic Necks---form when magma hardens in a volcano’s pipe and the surrounding rock later wears away.

2.     Dikes---form when magma forces itself across rock layers and hardens.

3.     Sills---form when magma squeezes between horizontal rock layers and harden.

4.     Dome Mountains---form when uplift pushes a large body of hardened magma toward the surface. The hardened magma forces the layers of rock to bend upward into a dome shape.

5.     Batholiths---masses of rock formed when a large body of magma cools inside the crust.

Chapter 4 Study Guide----Test on Tuesday, December 5th!!!!!

Study Guide

Chapter 4 Test

Know all of your vocabulary!  Take your Vocab Folder home to study.

What is stress?

Answer:  Stress is a force that acts on rock to change its shape or volume.

What works over millions of years to change the shape and volume of rock?

·       Tension-the stress force that pulls on the crust and thins rock in the middle.

·       Compression-the stress force that squeezes rock until it folds or breaks.

·       Shearing-the stress that pushes a mass of rock in two opposite directions.

What is a fault?

Answer:  A fault is a break in the rock of the crust where rock surfaces slip past each other.

How do faults form?

Answer:  When enough stress builds up in rock, the rock breaks, creating a fault.

Name and describe the 3 main types of faults.

o   Normal Fault-the fault cuts through rock at an angle, so one block of rock sits over the fault, while the other block lies under the fault.

*The hanging wall moves down!

o   Reverse Fault-this fault has the same structure as a normal fault, but the blocks move in the reverse direction.

*The hanging wall moves up!

o   Strike-Slip Fault-the rocks on either side of the fault slip    past each other sideways, with little up or down motion. (transform boundary)

How does plate movement create new landforms?

o   Anticlines-a fold in a rock that bends upward into an arch.

o   Syncline-a fold in rock that bends downward to form a V-shape.

o   Folded mountains-the collision of two plates can cause compression and folding of the crust over a wide area.  Folding produced some of the world’s largest mountain ranges—The Himalayas in Asia  AND The Alps in Europe.

o   Fault-block mountains-two plates move away from each other and tension forces create many normal faults.  As the hanging wall of each normal fault slips downward, the block in between now stands above the surrounding valleys, forming a fault-block mountain.

o   Plateau-the forces that raise mountains can also uplift, or raise, plateaus (large areas of the land elevated high above sea level).

What causes earthquakes?

Answer:  The forces of plate movement produce stress in Earth’s crust, adding energy to rock and forming faults. Eventually the stress increases along a fault until the rock slips or breaks, causing an earthquake.

What are seismic waves?

Answer:  Seismic waves are vibrations that are similar to sound waves.  They travel through Earth carrying energy released by an earthquake.

What is the focus?

Answer:  The focus is the area beneath Earth’s surface where rock that was under stress begins to break or move.  This action triggers the earthquake.

What is the epicenter?

Answer:  The point on the surface directly above the focus is the epicenter.

Types of seismic waves:

1)   P Waves—The first waves to arrive are primary waves, or P Waves.  These waves compress and expand the ground like an accordion.

2)   S Waves—The secondary waves that come after the P Waves are S Waves.  These waves vibrate from side-to-side or up and down.

3)   Surface Waves—When P Waves and S Waves reach the surface, some of them become Surface Waves.  These move more slowly that P and S Waves, but they can produce severe ground movements.

How are earthquakes measured?

Answer:  Geologists measure earthquakes in two ways. 

1)   The amount of earthquake damage or shaking that is felt is rated using the Modified Mercalli Scale.

*The Modified Mercalli Scale rates the amount of shaking from an earthquake.  It is rated by people’s observations, without the use of instruments.  This scale is used in regions where there aren’t many instruments to measure an earthquake.  It uses Roman numerals to rate the damage and shaking at any given location.

2)   The magnitude (SIZE) of an earthquake is measured on a seismograph using the Richter Scale or the Moment Magnitude Scale.

*An earthquakes magnitude (size) is a single number that geologists assign to an earthquake based on the earthquake’s size. 

*THE EARLIEST MAGNITUDE SCALE IS CALLED THE RICHTER SCALE.

*The Moment Magnitude Scale rates the total energy an earthquake releases.

A magnitude of below 5 is a small earthquake and causes little damage.

A magnitude above 6 is a large earthquake and can cause great damage.

The most powerful earthquakes, with a magnitude of 8 or above, are rare and cause tremendous damage.

How is an epicenter located?

Answer:  Geologists use seismic waves to locate an earthquake’s epicenter using data from thousands of seismograph stations set up all over the world.

How do seismographs work?

Answer:  Seismic waves cause a simple seismograph’s drum to vibrate, which in turn causes the pen to record the drum’s vibrations.  The suspended weight with the pen attached moves very little.  This allows the pen to stay in place and record the drum’s vibrations.  The rest of the seismograph is anchored to the ground and vibrates when seismic waves arrive.

What is a seismogram?

Answer:  The pattern of lines, called a seismogram, is the record of an earthquake’s seismic waves produced by a seismograph.

What patterns do seismographic data reveal?

Answer:  Geologists have created maps, by using seismographic data, of where earthquakes occur around the world to show that earthquakes often occur along plate boundaries.

Where in the United States are the possibilities of major earthquakes more likely?

Answer:  Plates meet along the Pacific coast in California, Washington state, and Alaska, causing many faults.