Grade 8 Earth Science

Chapters 14 & 16: Atmosphere & Climate

Composition of Earth’s Atmosphere

Layers of Earth’s Atmosphere

Info. Relating to the Atmosphere

• Troposphere-

• Ionosphere-

Where does weather occur?

Why does the frequency of radio stations break up?

Ozone Layer

• What is ozone?

• What is the ozone layer?

• Where is the ozone layer located?

• How does ultraviolet radiation affect you?

• Describe CFC’s (chlorofluorocarbons)…

Energy From the SunType of Energy Transfer Description Example

Radiation Transfer of energy through electromagnetic waves

Conduction Transfer of energy that occurs when molecules bump into one another

Convection Transfer of heat by the flow of heated material

Water Cycle Words to Know

• What is a cycle? • Evaporation-

Transpiration-

• Condensation-

• Precipitation-

Movement of Air• Winds are caused by the uneven heating

between the Equator & the Poles– Hot air rises– Cool air settles

• Coriolis Effect: deflects all free-moving objects (such as air and water) to the right north of the equator and left to the south

Wind Systems• The Prevailing Winds are caused

by the rotation of the earth and the position of the continents.

SURFACE WINDS• Easterlies –• Westerlies - • Trade Winds – • Doldrums -

HIGH ALTITUDE AND LOCAL WINDS

• Jet Stream – winds at high altitude (where the jets fly). Flows from west to east in northern hemisphere and opposite direction in the southern hemisphere

• Local Winds – are caused by convection currents examples are Sea and Land Breezes

Climate Words to Know:Tropics-

Polar Zones-

Temperate Zones-

What is the difference between

weather & climate?

El Nino ~ La NinaSome climatic changes last longer

than a season…

El Nino is a climatic event that starts in the tropical Pacific Ocean and sets off changes in the atmosphere (unusually warm ocean temperatures)

La Nina is El Nino’s counterpart which causes unusually cold ocean temperatures

Climatic Changes• Greenhouse Gases-

• Global Warming (Climate Change)

Chapter 17: Ocean MotionHow do oceans affect you?How do you affect oceans?

Composition of Oceans

• Earth’s surface is ______% ocean.

• _________ is a measure of the amount of solids dissolved in seawater.

• It has remained nearly ____________ for years.

Elements & Compounds in Ocean Water

Surface Currents

• Move water horizontally

• Parallel to earths surface

• Powered by winds

Importance: distribute equatorial heat

to other areas of earth

The Gulf Stream

Upwelling & Density CurrentsUpwelling Density CurrentsCirculation of ocean that brings deep, cold, nutrient-rich water to the surface

TOP to BOTTOM

•Important for fishing!•Contributes to San Francisco’s “famous fogs”

More dense seawater sinks under less dense seawater

HORIZONTAL

Ocean Waves & Tides

• Wave- rhythmic movement that carries energy through ________ or _______

• Ocean Waves carry energy through _________

Breaker- collapsing wave onto the shore

TIDES• Tide =

______ and ______ in sea level

• Tidal Range = the difference between the level of the ocean at ______ _______ and

______ _______

Tides are affected by the gravitational pull of the _______ and _____ on the earth’s waters.

The moon is closer to earth, and therefore, exerts a _________ gravitational pull.

How Tides Work…

Tapping Tidal Energy

A Tidal Dam Works Well…

A Tidal Dam Creates Problems…

Oceanography- Chapter 18

The Seafloor

Ocean Basin Features– Continental shelf-– Continental slope-– Abyssal plains-

Plate Boundary Structures- Mid ocean ridge-- trench

Mining the Ocean Floor

Salt has always been collected from the ocean water.

Now, we also collect oil, gas & minerals from the sea.

Life in the Ocean Energy Relationships:

- photosynthetic organisms capture the sun’s energy and make food using light energy, carbon dioxide, and water through _______________

- chemosynthetic organisms do not rely on sunlight; instead, they rely on ____________

Ocean LifePLANKTON NEKTON BENTHOS

-Tiny marine algae & animals-drift with currents

-actively swim -plants, algae & animals that live on the lowest levels of the ocean

Examples: Examples: Examples:

Pollution & Marine Life

ASTRONOMY!!!

Chapter 22: Sun-Earth-Moon System

Planet Earth Data

• Sphere: round, 3-D object whose surface at all points is the same distance from its center

• Axis: imaginary line around which earth spins• Rotation: spinning of Earth on its axis– causes day & night– 1 rotation takes 24 hours

Earth’s Magnetic Field

Earth’s Revolution

• Revolution: yearly orbit around the sun• Earth’s orbit is an ellipse

(NOT “circle” or “eclipse”)• Revolution around the sun takes 365 days

SEASONS

• Earth’s TILT on its axis causes the seasons

• Hemisphere tilted toward the sun receives more hours of sunlight & direct rays

Equinoxes & Solstices

Earth’s Moon

• The moon rotates on its axis and revolves around the earth once every 27.3 days.

• Because these two motions take the same amount of time, we only see ONE side of the moon.

Moon Phases

• Moon Phase: apparent change in the shape of the moon as seen from earth

• Depends upon the relative positions of the earth, sun and moon

• WAXING = more of the moon becomes visible• WANING = less of the moon becomes visible

Solar Eclipse- moon comes between the earth & sun, casts a shadow on earth

Lunar Eclipse- earth comes between the moon & sun, blocks sunlight from reaching moon

The Solar System• Collection of planets & other objects that orbit the sun

• Inner Planets (rocky, solid core)• Outer Planets (gaseous)

Size & Composition

Atmosphere Temperatures

Surface Features

Moons(number/names)

# of Earth Days to

Orbit the Sun

The Inner Planets

Size & Composition

Atmosphere Below the Atmosphere

Notable Features

Moons(number/names)

# of Earth Days to

Orbit the Sun

The Outer Planets

OTHER OBJECTS IN SPACE

• Comets (Cupids, Donner, Blitzen) orbit the sun

• Composed of dust and rock particles mixed in with frozen water and gases.

• The most well-known comet is Halley’s Comet. It is visible on Earth every76 years.

Meteors

• Meteoroids - A large rock traveling through space, composed of nickel and iron.

• Meteor – A meteoroid that reaches the earth’s atmosphere.

AKA: “shooting star”• Meteorite – A meteor that

hits the earth’s surface

• Asteroids – are pieces of rock that orbit the sun between Mars and Jupiter (The Asteroid Belt)… What are they doing there?

Stars and Galaxies

Chapter 24

Constellations

• Constellations – groups of stars that form patterns that look like familiar objects or characters

• Modern astronomers have divided the sky into 88 constellations

• Polaris is the North Star

• Circumpolar Constellations 5 constellations that circle Polaris and are visible all year long in the

Northern Hemisphere

Magnitude

• Apparent Magnitude– Measure of the

amount of light received by earth

• Absolute Magnitude– Measure of amount of

light actually given off by a star

Distance to Stars

• Parallax– Apparent shift in the position of an object

when viewed from 2 different positions

• Light Year– Distance light travels in 1 year– Light travels FAST (300,000 km/s)

Star Temperature

The Sun• STATS:– Average, middle-aged, yellow star– Produces energy by fusing hydrogen into helium in

its core

• Layers & Atmosphere– Photosphere– Chromosphere– corona

Features of the Sun

• Sunspots, prominences, flares– All caused by the

intense magnetic field of the sun

H-R Diagram

Evolution of Stars

GALAXIES: large group of stars, gas, & dust held together by gravity

Elliptical Spiral Irregular

The Milky Way

• What you know as HOME• Spiral galaxy

Doppler Shift

• The Doppler Shift causes wavelengths of light coming from galaxies to be compressed or stretched– Used to determine whether objects are moving

toward or away from the earth

– Red Shift (appear to move away)– Blue Shift (appear to move toward object)