CHAPTER THREEThe Dynamic Earth

Earth As A System

Four “Spheres”

Geosphere Atmosphere Hydrosphere Biosphere

a set of connected things or parts forming a complex whole, in particular

Four “Spheres”

Geosphere12,756 km

(diameter)

Atmosphere1,000 km

HydrosphereAll water, incl

atmospheric water

Biosphere9 km above surface

11 km beneath surface

Sphere Sizes

Demonstration

Lesson

Homework

Plate Tectonics

Idea that lithosphere is broken into plates that slide across asthenosphere

Responsible for current position

of continents Landforms ,

volcanoes, earthquakes

Terms to Note

Plate tectonics Convergent

boundary Divergent

boundary Transform

boundary Subduction Sea-floor

spreading

www.newpathlearning.com

Volcanoes

Born when magma reaches and penetrates earth’s crust—usually at plate boundaries

Melted rock, gas, and

water under intense heat and pressure

http://ees.as.uky.edu/volcano-songs

Volcanoes

Occurs between both continental and oceanic plates

Can form: On land

At divergent boundaries

At convergent boundaries

Volcanoes

Occurs between both continental and oceanic plates

Can form: Underwater

At divergent boundaries

At convergent boundaries

Ring around the pacific plate where 75% of world’s volcanoes occur

Ring of Fire

Spots where volcanoes occur AWAY from plate boundaries simply because magma has come

close to the surface

Hot Spots

Example: Hawaiian Islands

Eruptions Can be quiet or

explosive Can cause lots of

damage Environmental Effects:

Forms rocks silica, basalt, pumice,

obsidian, rhyolite Kills vegetation Changes atmosphere

Dust, ash, climateParacutinVideo OneVideo Two

Weathering and Erosion Erosion- removal and

transport of surface material

Can occur because of wind or water

Can be mechanical, chemical, or both Demonstrations

Frost wedging- a common form of weathering in temperate regions Demonstration Violent Hawaii

Circle the gentlest slope in RED. (Merna)

Circle the steepest slope in BLUE. (Grace)

Color in the peak of the landform in GREEN. (Jules)

Draw a rough profile of the section from G-H. (Ann-Houston and Bridget)

What kind of landform is this? (Rachel)

Circle the gentlest slope in RED. (Merna)

Circle the steepest slope in BLUE. (Grace)

Color in the peak of the landform in GREEN. (Jules)

Draw a rough profile of the section from G-H. (Ann-Houston and Bridget)

What kind of landform is this? (Rachel)

3.2—The Atmosphere

What is the atmosphere?

Atmos = vapor, steam (Greek) Combination of gases which surrounds

earth and makes life sustainable About 50 km thick (31 miles) Divided into layers based on

temperature and pressure changes

Remember– this was the 1.0m long section of our demonstration outside…

Functions of the Atmosphere Protection of all life from dangerous sun rays Allows sunlight in Protects from drastic temperature variation (insulates earth) Transports energy and water vapor Stores nitrogen and CO2 (for plants) and oxygen (for

animals) Protects from smaller meteorites

Atmosphere Profiles Homework Check1. Draw the line that you came up

with in RED. (Ava)

2. Draw a BLUE bracket around the troposphere. (Catherine)

3. Draw a GREEN bracket around the Stratosphere. (Grace)

4. Draw a BLACK bracket around the thermosphere. (Alice)

5. What is the temperature range of the atmosphere surrounding an airplane at cruising altitude? (Christine)

___________ ºC

6. Write on the profile where the aurora borealis originates. (Kathy)

Atmosphere Profiles

Layers of the Atmosphere

Pauses

Aurora BorealisVideo

Homework– For MONDAY

Read article on ozone layer and global warming Answer questions

We will USE this information for a discussion

Homework Check

Alice

Christine

Catherine

Kathy

Ava and Jules

Energy in the Atmosphere

Remember– part of purpose of atmosphere is

Letting sunlight in Keeping bad sun rays out Insulating

Remember– Energy is neither created nor

destroyed—only transferred.

Heat and light are forms of ENERGY

Energy in the Atmosphere

So…2 questions: Where does the energy (heat and

light) on earth come from? How is it transferred?

3 mechanisms for heat transfer:

1)Radiation2)Conduction3)Convection

Textbook, p. 74-75

1) Radiation Moves E through SPACE as WAVES

Reaches earth as electromagnetic radiation Includes visible light, infrared radiation, and

ultraviolet (UV) light

Only about 2 billionths of this E from sun hits earth Of this E, ½ reaches the Earth’s surface

Where does the rest go?

DEMONSTRATION

Things that are NOT touching each other

1) Radiation

Textbook, p. 74-75

2) Conduction Moves E from one object to another

Warmth emitted by earth’s surface is reabsorbed by the air at the surface Which layer of the atmosphere touches the

earth’s surface?

DEMONSTRATION

Between two things in contact with one another

2) Convection Moves E from one fluid to another

Occurs because of DENSITY differences Warm air is LESS DENSE than cool air, so it

______________ When the warm air cools, it is MORE DENSE, so it

_________________ Creates CONVECTION CURRENTS

Occurs in molten rock, air, and water Responsible for WEATHER

DEMONSTRATION

Fluid includes air, water, AND molten rock

Research Groups

Assignment Tasks: Gather in (+/-) groups

(+) meets in back of classroom (-) meets in front of classroom

Make a plan for Friday’s discussion What does it mean to be +/- in this

debate? Discuss research so far

Concerns? Good finds?

Begin Making ROUGH outline

You have until 9:25.

Common Confusion (homework) Ozone Layer Greenhouse

EffectWhere is it? (Grace)

What does it do? (Kathy)

How does pollution affect it?(Rachel)

What are the issues? (Merna)

Common Confusion

Ozone Layer Greenhouse Effect

Where is it? Concentrated in Stratosphere

Throughout atmosphere

What does it do? Blocks OUT harmful UV rays

Keeps enough radiation IN

How does pollution affect it?

Depleted by pollution Increased by pollution

What are the issues? Ozone thinning = too many UV rays

Too many greenhouse gases = rise in global temperature

Review Picture (#29)

Question: Talk about it

• Which type of heat transfer is MOST important in the atmosphere?

• Why?

Greenhouse Effect

Greenhouse gases insulate earth and keep enough warmth IN

Mostly water vapor, methane, carbon dioxide, nitrous oxide

TOO many greenhouse gases keeps TOO much warmth in

3.3– The Hydrosphere and Biosphere

3.3– The Hydrosphere and Biosphere

Review:• Spheres of the earth

(4)• Geosphere• Atmosphere• Hydrosphere• Biosphere

• Earth is a SYSTEM• Biosphere largely

dependent on hydrosphere

Hydrosphere

Includes all water on or near Earth’s surface

Water = matter So, remains IN Earth’s

closed system—recycled and reused

The Water Cycle (Hydrologic Cycle)

1. From liquid to gas

2. From gas to tiny droplets of liquid

3. From tiny droplets to larger drops of liquid

The Water Cycle (Hydrologic Cycle)

Smaller parts of cycle

Oceans

Four/Five oceans, but considered one WORLD OCEAN

Covers over 70% Earth’s surface

Helps regulate Earth’s climate

Ocean Facts and Figures

Size Depth Currents Special Features

Pacific Largest(165,640,000 km2)(63,953,604 mi2)

Deepest(4,280 m)(14,042 ft)

Surface current: Clockwise in north; Counterclockwise in south

Challenger Deep; deeper than Mt. Everest is tall!

Atlantic Second Largest(81,630,000 km2)

Second Deepest(3,926 m)

Same as above

Puerto Rico Trench; 28,231 ft deep

Indian Third Largest(73,420,000 km2)

Third Deepest(3,890 m)

Java Trench; 25,344 ft deep

Arctic Smallest Most Shallow(1,205m)

Mostly covered with floating ice (pack ice)

Ocean Water

Contains salts Picked up from

rocks over millions of years

Gathered from underwater volcanoes

Salinity = concentration of all dissolved salts Avg. 3.5 % by

weight

55%30.6%

7.7%

3.7%

1.2% 1.1% 0.7%

Ocean Water Composition

ChlorineSodiumMagnesiumSulfurCalciumPotassiumOther

• Where would you expect HIGH salinity?

• Low salinity?

Temperature ZonesTemperature/ Facts

Surface Warm for 100 m; Surface Currents mix warm top water with layers below

Thermocline Temp drops fastest of all layers

Deep Very cold (avg. 2˚C)

• NO Wonder Journal this week

• Watch NewPath Lecture and

complete notes• Work on Research

Homework

Bridget: Draw Gulf StreamJules: Circle the two cities

Open Question:

Why the temperature difference?

On an index card:

On blank side:

1. Draw experimental design

On lined side:

2. What do you THINK will happen?

Convection Current Demo

On an index card:

On blank side:

1. Draw experimental design

On lined side:

2. What do you THINK will happen?

3. What actually happens?

4. Is this what SHOULD have happened?

Revisit Convection Current Demo

3.3– The Hydrosphere and Biosphere

Review:• Spheres of the earth

(4)• Geosphere• Atmosphere• Hydrosphere• Biosphere

• Hydrosphere includes:• Water in

atmosphere • Oceans• Freshwater/

Groundwater

Fresh Water and Groundwater

Fresh water - water that is not salty

3% of water on Earth BUT most is “locked

up” in icecaps and glaciers

Other fresh water found in lakes, rivers, wetland, soil, rock layers, and atmosphere

Groundwater- fresh water that trickles into ground from rain and runoff

Less than 1% of all water on earth

Fulfills water needs for Drinking water Agriculture Industrial uses

Aquifers- rock layers that store groundwater

3.3– The Hydrosphere and Biosphere

• Biosphere includes:• All parts of earth

that can be inhabited by life

Biosphere

Made up of: Upper part of geosphere Most of hydrosphere

12 km into ocean (7.5 mi) Lower part of atmosphere

Up to 9 km (5.5 mi)

Why is life limited to these spaces?

Open System vs. Closed SystemWhich system describes earth?

Why?

What kind of energy enters the earth system?

What kind of energy exits the earth system?

Meet in Groups

Tasks:• Discuss research• Work on outline• Discussion will include

the following:• Define global warming• Is it a problem? (why

do we care?)• What should we be

doing about it?

• Finish outline for homework

• 5 minutes to talk at start of class Monday