Always Strive . . .
"To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science."
Albert Einstein
Tuesday, January 23, 2018
Wednesday, January 17, 2018
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
Tuesday, January 2, 2018
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.
Thursday, December 7, 2017
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: ParicutÃn 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.
Monday, November 20, 2017
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.
Wednesday, November 1, 2017
Chapter 3 Test on Tuesday, November 14th!!!!!!!!!!!! Begin studying now!!!!!!!!!!!!!!
Chapter 3 –
Plate Tectonics – Study Guide
· Know all
your vocabulary. Be able to match each
definition to the word it defines.
· Describe
Alfred Wegener’s hypothesis about the continents.
Answer: Wegener’s hypothesis was that all the
continents were once joined together in a single landmass and have since
drifted apart. Wegener was a German
scientist, and his hypothesis was formulated in 1910.
· What name
did Wegener give the supercontinent, or single landmass, that existed about 300
million years ago?
Answer: Pangaea
· What
evidence did Wegener suggest supported his hypothesis?
Answer: He pieced together maps of Africa and South
America, and noticed that mountain ranges on the continents line up. He also noticed that coal fields in Europe
and North America also match up. Also,
Wegener used fossils to support the hypothesis because they contained fernlike
plants and freshwater reptiles found in places now separated by oceans. The plants couldn’t have grown today in some
of the places the fossils were discovered, and the reptiles couldn’t have swum
the distance across the oceans.
· More
evidence confirming the hypothesis of the continental drift was published in
1957 by geologist Marie Tharp. What
evidence did she present?
Answer: Data taken from ships showed how the height
of the ocean floor varied, and that in certain places the floor of the ocean
appeared to be stitched together like the seams of a baseball. The seams formed mountain ranges that ran
along the middle of some ocean floors.
These were called mid-ocean ridges.
· What device
using sound waves to measure the distance to an object was used in the
mid-1900s by scientists to map mid-ocean ridges?
Answer: sonar
· Describe the
process of sea-floor spreading.
Answer: Sea-floor spreading begins at a mid-ocean
ridge, which forms along a crack in the oceanic crust. Along the ridge, new molten material from
inside Earth rises, erupts, cools, and hardens to form a solid strip of
rock. More crust is added to the ocean
floor. At the same time, older strips of
rock move outward from either side of the ridge.
· Name 3 types
of evidence that geologists have found for sea-floor spreading.
Answer:
1-Ocean-floor Material shows
rocks shaped like pillows that only form when molten material hardens quickly
after erupting under water.
2-Magnetic Stripes-as magma
erupts, cools, and hardens, magnetic minerals inside the rock line up in the
direction of Earth’s magnetic poles. The
pattern of magnetic stripes on one side of a mid-ocean ridge is usually a
mirror image of the pattern on the other side of the ridge.
3-Drilling Samples-Rock
samples from the ocean floor show that the farther away from a ridge a rock
sample was taken, the older the rock was.
The youngest rocks were always found at the center of the ridges.
· What happens
at deep-ocean trenches?
Answer: In a process taking tens of millions of
years, part of the ocean floor sinks back into the mantle at deep-ocean
trenches.
· Explain
subduction.
Answer: Crust closer to a mid-ocean ridge moves away
from the ridge and toward a deep-ocean trench.
The new oceanic crust is hot, but as it moves away from the mid-ocean
ridge, it cools. As it cools, it becomes
more dense. Eventually, as it moves, the
cool, dense crust might collide with the edge of a continent. Gravity then pulls the older, denser oceanic
crust down beneath the trench and back into the mantle. This is called subduction.
· Earth’s
plates meet at boundaries. What are the
three types of boundaries? Explain each.
Answer:
1. Divergent Boundary-plates that move apart, or
diverge from each other;
2. Convergent Boundary-plates that come together,
or converge;
3. Transform Boundary-plates that slip past each
other, moving in opposite directions.
The sides of the plates are rocky and jagged, so the two plates can grab
each other and “lock” in place. Forces
inside the crust can cause the two plates to unlock. Earthquakes often occur when this
happens. Crust is neither created or
destroyed at transform boundaries!!!!!
· What is the
‘theory of plate tectonics’?
Answer: It states that Earth’s plates are in slow,
constant motion, driven by convection currents in the mantle.
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