Benchmark Study GuideStandard 8-3: Students will demonstrate an understanding of materials that determine the structure of Earth and the processes that have altered this structure.

8-3.1 Summarize the three layers of Earth – crust, mantle, and core – on the basis of relative position, density, and composition.

Layer Location/Relative Position

Composition Important Facts Density Thickness

Crust Outermost Layer Solid 2 types of crust: Continental (contains granite rock) and Oceanic (contains basalt rock which is most dense and the youngest because it’s being recycled through subduction.

Least Dense Layer

Thinnest

Lithosphere Lies between the of the crust and upper Mantle

Solid Contains the lithospheric plate that moves

Dense Thin

Asthenosphere Top layer of the Mantle (the upper mantle)

Soft Solid or Soft Rock

The lithosphere plates moves on top of the asthenosphere

Dense Thin

Mantle Upper, Middle, and Lower Mantle

Soft Solid or Soft Rock

Convection currents in the mantle moves the asthenosphere layer that moves the lithospheric plates

Gets denser as you move down from the upper mantle to the lower mantle

Thickest

Outer Core Between the Mantle and Inner Core

The Only Liquid Layer

The only liquid and deals with the magnetic field (contains nickel and iron metals)

Denser than the mantle

Thick (comes after the mantle

Inner Core Innermost Layer Solid Has enough pressure for it to remain as a solid

Most Dense Thick (Comes after the Outer Core

8-3.6 Explain how the theory of plate tectonics accounts for the motion of the lithospheric plates, the geologic activities at the plate boundaries, and the changes in landform areas over geologic time.

The Theory of Plate Tectonics The theory of plate tectonics explains why and how large sections of Earth’s crust, called lithospheric plates ,

move. A hypothesis of continental drift was developed before the present theory of plate tectonics. It was based on continent shape, fossil evidence, rock, and climate clues. This hypothesis later led to the theory of plate tectonics when evidence was found as to why the plates could move. Plate tectonics explains how many Earth features form.

Motion of the Lithospheric Plates Plates float on the upper part of the mantle. Convection currents can cause the asthenosphere to flow slowly carrying with it the plates of the lithosphere. This movement of plates changes the sizes, shapes, and positions of Earth’s continents and oceans. Plates moves from 1-10 cm per year.

Divergent Boundary Convergent Boundary Transform Boundary

Plates spread or move apart

most located along mid-ocean ridge (sea-floor spreading

Forms new crust because magma pushes up and hardens between separating plating

Continental Crust forms Rifts (on land)

Oceanic Crust Forms Ridges (in oceans)

Can cause Volcanic Activity

Plates come together and collide activity depends upon the types of crust that meet more dense oceanic plate slides under less dense

continental plate or another oceanic plate –

Subduction Zone, some crust is destroyed

Has 3 types of collisions- Continental –Continental (CC): forms

mountains: two continental plates converge, both plates buckle and push up into mountain ranges

- Continental-Oceanic (CO): Has a subduction zone and can cause volcanic activity

- Oceanic-Oceanic (OO): Has a subduction zone and can cause volcanic activity and can also form trenches

Plates slides past each other

crust is neither created nor destroyed

Earthquakes occur frequently along this type of boundary Forms faults

Ex: San Andreas Fault

Force or Stress: Tension Force or Stress: Compression Force or Stress: Shearing

Faults: Normal Fault Fault: Reverse Fault Fault: Strike-slip fault

Changes in Landform areas over Geologic Time Plates move at very slow rates – from about one to ten centimeters per year; At one time in geologic history the continents were joined together in one large landmass that was called Pangaea. As the plates continued to move and split apart, oceans were formed, landmasses collided and split apart until the

Earth’s landmasses came to be in the positions they are now; Evidence of these landmass collisions and splits comes from fossils, landform shape, features, and rock

structures, and climate change; Landmass changes can occur at hot spots (volcanoes) within lithospheric plates; Earth’s landmasses will continue to move and change during the geologic time of the future.

8-3.7 Illustrate the creation and changing of landforms that have occurred through geologic processes (including volcanic eruptions and mountain-building forces).

Volcanic Eruptions Volcanic eruptions are CONSTRUCTIVE in that they add new rock to existing land and form new islands .

Volcanic eruptions can be DESTRUCTIVE when an eruption is explosive and changes the landscape of and around the volcano.

MAGMA from the MANTLE rises to Earth’s surface and flows out an opening called a VENT Magma that reaches Earth’s surface is known as LAVA. The vent as well as the mountain that forms around it from cooled lava, ash, cinders, and rock is called a

VOLCANO. Most volcanoes occur along plate boundaries; an area in the Pacific Ocean where volcanoes are common is

called the RING OF FIRE.

Mountain-building forces Forces, or stresses , that cause rocks to break or move are:

o Tension —forces that pull rocks apart o Compression —forces that push or squeeze rocks togethero Shearing —forces that cause rocks on either side of faults to push in opposite direction

Forces or stresses (for example, tension and compression) on rocks in the lithosphere can cause them to bend and stretch.o This bending and stretching can produce mountain ranges.o If pressure is applied slowly, folded mountains form.

Forces or stresses (for example, tension, compression, or shearing) great enough to cause rocks to break can create faults. FAULTS are places in Earth where the rocks break.

If normal faults uplift a block of rock, a fault-block mountain forms

8-3.8 Explain how earthquakes result from forces inside Earth.

If the pressure or stress becomes too great, the rock breaks at a weak point along the fault and ENERGY is released. The energy spreads outward in all directions as vibrations called SEISMIC WAVES. The FOCUS of the earthquake is the point in the crust, or mantle, where energy is released. The EPICENTER is the point on Earth’s surface directly above the focus; energy that reaches the surface is greatest at

this point.

RECAPEpicenter: is located right above the focus and has the greatest amount of energyFocus: releases the energy (seismic waves)Fault: a break in the Earth’s Crust (is where an earthquake takes place)Seismic waves: is the energy that is being sent out from the focus

8-3.2 Explain how scientists use seismic waves – primary, secondary, and surface waves – and Earth’s magnetic fields to determine the internal structure of Earth.

Types of Seismic Waves

Movement/Description Travels Through Illustration

Primary Waves

(P Waves)

First Wave to Move out from the earthquake focus, the point where the energy is released

Travel the fastest of the three waves

Push and pull rock creating a back-and-forth motion in the direction the wave is moving(known as longitudinal or

compressional waves)

Move through solid and liquid layers of Earth (therefore it can move through all layers)

Secondary Waves

(S Waves)

2nd wave to Move out from the earthquake focus

Move slower than primary waves

Move at right angles to primary waves causing rocks to move up and down and side to side (known as transverse wave: perpendicular to the wave motion)

Can only move through SOLID rock therefore it CAN NOT TRAVEL THROUGH THE OUTER CORE because it is a LIQUID. IT STOPS AT THE OUTER CORE.

Surface Waves

Form when P and S waves reach the surface

SLOWEST BUT MOST DESTRUCTIVE

Can cause the ground to shake making rock sway from side to side and roll like an ocean wave

Move through solid and liquid layers of Earth (therefore it can move through all layers)

Seismic WavesScientists use the principle that the speed and direction of a seismic wave depends on the material it travels through. How does scientist know or study the Earth’s Core? Because of the behavior of these different waves , scientists have indirect evidence for the solid inner core and liquid outer core of Earth because S waves don’t travel through the outer core because it’s a liquid. Also because earthquake waves travel faster through the mantle than through the crust, scientists know that the mantle is denser than the crust .

8-3.3 Infer an earthquake’s epicenter from seismographic data.

The EPICENTER is the point on Earth’s surface directly above where the energy is released in an earthquake; energy that reaches the surface is greatest at this point. The energy spreads outward in all directions as vibrations called SEISMIC WAVES. Seismic waves can be measured and recorded by a SEISMOGRAPH. The vibration record, called a SEISMOGRAM, looks like jagged lines on paper.

SEISMOGRAPH SEISMOGRAM

S-P INTERVALS To find the SP intervals, you have to subtract the P Wave from the S Wave. Measuring the time between the arrival of the P and S waves determines the distance between the recording

seismograph and the earthquake epicenter.

What are the S-P Intervals?

TRIANGULATION identifies the epicenter of an earthquake. The location of an earthquake’s epicenter is found by plotting 3 circles on a map from the records of three seismograph stations and finding the point where the three circles intersect.

8-3.4 Explain how igneous, metamorphic, and sedimentary rocks are interrelated in the rock cycle.

TYPE OF ROCK FOUND DESCRIPTION PROCESSESIGNEOUS ROCKS Near or

Inside of a Volcano

Form from magma and lava

Intrusive (cools slowly inside the volcano) forms as magma coolsExtrusive (cools rapidly outside the volcano) forms as lava cools

Look: glassy, grainy, can have holes in them

Ex: Basalt, granite, obsidian, pumice, and scoria

Melting (solid to liquid) and

Crystallization (liquid to solid)

SEDIMENTARY ROCKS Near Bodies of Water or where bodies of water use to be

Contain Fossils

Look: often form layers, grainy

Ex: Conglomerate, Shale, Sandstone, Coal, and Limestone

Form from compaction and cementation (sediments are compacted and cemented together) of rock pieces, mineral grains, or shell fragments called sediments.

METAMORPHIC ROCK Beneath the Earth’s Surface

Forms when rocks are changed into different kinds of rocks by great heat and/or pressure – they are heated, squeezed, folded, or chemically changed by contact with hot fluids. (Subduction)

Starts as either an igneous or sedimentary rock

Foliated: contains layersNon-Foliated: does not contain

Forms from heat and pressure

any layers

Ex: Gneiss, Slate, Quartzite, and Marble

THE ROCK CYCLEThe rock cycle is an ongoing process. The sample diagram illustrates the series of natural processes that can change rocks from one kind to another

8-3.5 Summarize the importance of minerals, ores, and fossil fuels as Earth resources on the basis of their physical and chemical properties.

Earth resources (minerals, ores, and fossil fuels) have properties that make them important and useful. The two types of properties are: Physical properties; for example, hardness, luster, color, texture, the way a mineral splits, or density Chemical properties; for example, the ability to burn, the reactivity to acids

Three common Earth resources that have importance based on their properties are:

Minerals All rocks are a mixture of many different substances. The individual substances that make up rocks are called

MINERALS. Natural, solid materials found on Earth that are the building blocks of rock; each has a certain chemical makeup and

set of properties that determine their use and value. Are Inorganic

Ores Any rock containing a metal together with impurities is called an ORE. Pure metal is obtained by mining an ore and then removing the impurities by heat or by chemical processes. Minerals that are mined because they contain useful metals or nonmetals.

Fossil fuels Natural fuels that come from the remains of living things; fuels give off energy when they are burned.

EARTH RESOURCESFacts: The world depends on energy. Energy is the ability to change. People use many different energy resources; however, they mainly use it to burn energy. Energy resources that cannot be replaced, or renewed, are called nonrenewable resources.

Nonrenewable Resources Fossil Fuels : are nonrenewable energy resources that form over millions of years from remains of dead

plants and other organisms such as planktons. Fossil Fuels are used to make gasoline for cars, to heat homes, to generate electricity, to cook (natural gas)

or heating oil, make plastic, and etc…

3 types of fossil fuels:

1. Coal: a solid sedimentary rock form from layers of ancient plant matter, most abundant fossil fuel, and is remove by coal mining. COAL Is Organic because the sediments that make up coal consists of dead plants, shells, or animal skeletons.

2. Oil or petroleum : a liquid hydrocarbon (contain the elements hydrogen and carbon) that is used mostly for making heating oil, gasoline, and plastics. IS ALSO ORGANIC

3. Natural Gas: gaseous and is used mostly for heating and cooking. IS ALSO ORGANIC

Oil and Natural gas are removed by extraction. First a narrow hole or well is drilled down through rock to the oil deposit. Equipment is put into the well to control the flow and the oil or gas is extracted or pumped.

Conserving Fossil Fuels: Turning off lights, Make sure doors and windows are shut tight so heat won’t leak out, Run your air condition as little as possible, and Add insulation to help save energy

Nuclear Energy : Alternative energy source of energy produced from atoms. This energy, produced by nuclear fission, can be used to make electricity or power a submarine. (Nuclear Power Plants)

Renewable Resources : energy resources that can be renewed or replaced Wind Water Sunlight Living Organisms (trees)

8-3.9 Identify and illustrate geologic features of South Carolina and other regions of the world through the use of imagery (including aerial photography and satellite imagery) and topographic maps.

Imagery Highflying aircraft and satellites high above Earth use sensors and cameras to gather information about Earth’s

landforms and resources. Computers create images from the data; scientists identify specific features by the combination of colors and

shapes that the feature makes on the satellite image.

Geologic features (for example, mountains, river and tributary flow, lakes, farmland, forests, Carolina bays, or coastal features) can be identified using South Carolina satellite images and aerial photographs, as well as other imagery from regions of the world.

ARERIAL PHOTO: OF A SPECIFIC AREASATELLITE PHOTO

Topographic maps These are maps that use symbols to portray the land as if viewed from above.

They provide information on elevation, relief, and slope of the ground surface, as well as the location of roads, buildings, swamps, and other features, natural and man-made.

Along with the scale and symbols, the contour lines and the contour interval are critical to understanding the topographic map.

TOPOGRAPHIC MAP SYMBOLS

REVIEW QUESTIONS:1. (8-3.1) The order of the layers of the Earth from

thickest to thinnest is __________.a. Crust, Mantle, Outer Core, Inner Coreb. Inner Core, Outer Core, Mantle, Crustc. Mantle, Outer Core, Inner Core, Crustd. Outer Core, Inner Core, Crust, Mantle

2. (8-3.1) The layers of the Earth that are completely solid include the __________.

a. Crust and Inner Coreb. Crust and Outer Corec. Inner Core and Mantled. Mantle and Outer Core

3. (8-3.2) Scientists can infer the composition of the cores using seismic

waves. The Outer Core is classified as a liquid because __________.

a. P-waves bend at the coresb. P-waves pass through the coresc. S-waves bend at the coresd. S-waves stop at the cores

Use the Data Table to answer items #8 and #9.

Wave Motion SpeedA Straight FastB Up and Down MediumC Rolling VariesD Sways Slow

4. (8-3.2) The Primary Waves correspond to the traits listed for __________.

a. Wave Ab. Wave Bc. Wave Cd. Wave D

5. (8-3.2) The wave that can travel through all mediums except liquids is __________.

a. Wave Ab. Wave Bc. Wave Cd. Wave D

6. (8-3.3) Scientists need multiple seismograph stations for epicenter location for all of the following reasons EXCEPT __________.

a. That more circles give more accurate results.b. The epicenter could be anywhere in the first

circle.c. The epicenter may be anywhere on a circle.d. Without multiple stations, circles will not

align.

7. . (8-3.3) The letter marking the point on the surface above

the focus is __________.

a. Ab. Bc. Cd. D

8. (8-3.4) The processes shown above changed Rock 1 into Rock 2. Rock 2 is a __________.

a. Igneous Rockb. Metamorphic Rockc. Sedimentary Rockd. Any of the Rock Types

9. (8-3.4) Rock 1 most likely was __________.

a. Igneous Rockb. Metamorphic Rockc. Sedimentary Rockd. Any of the Rock Types

10. (8-3.4) The substance that formed from Rock 1 and becomes Rock 2 is __________.

a. Crystalsb. Mineralsc. Magmad. Sediment

11. (8-3.5) Fossil Fuels are considered useful to humans because they are___________.

a. burned for energy.b. easy to find.c. made of living things.d. natural resources.

12. (8-3.5) Petroleum (oil) is not an example of a mineral. This is because petroleum is __________.

a. a fossil fuel.b. a liquid.c. not valuable.d. organic.

13.. (8-3.6) Subduction Zones occur because __________.

A

C

B

D

ROCK 1 ??? ROCK 2Erosion Compaction

a. Continental Crust is less dense than Oceanic Crustb. Continental Crust tougher than the Oceanic Crustc. Oceanic Crust is blocked by Mountains on

Continentsd. Oceanic Crust melts at the Continent’s coasts

14. (8-3.6) The oldest crust in the diagram would be located at the point labeled __________.

a. Ab. Bc. Cd. D

15. (8-3.7) The event that most likely caused this change in landform was __________.

a. A Meteor Impactb. A Volcanic Eruptionc. An Earthquaked. Long-Term Erosion

16. (8-3.8) After an Earthquake, the seismic waves move out from the focus because of all of the

following events EXCEPT __________.

a. Energy is releasedb. Pressure levels changec. Rocks break at the focusd. The plates move outward

17. (8-3.8) The order of seismic waves leaving from the focus is __________.

a. P-wave, S-wave, Surface Waveb. P-wave, Surface Wave, S-wavec. S-wave, Surface Wave, P-waved. Surface Wave, P-wave, S-wave

18. (8-3.9) The Peak of the Mountain is located at __________.

a. Ab. Bc. Cd. D

19. (8-3.9) The elevation of Black Bear Camp is _________.

a. 460 mb. 520 m

C BA

D

c. 640 md. 720 m

20. (8-3.9) The river in this image is located at __________.

a. Ab. Bc. Cd. D

21. (8-3.9) The “X” in this image shows a __________.

a. Cityb. Fieldc. Forestd. Valley

BA