grade 8 earth science n.
Skip this Video
Loading SlideShow in 5 Seconds..
Grade 8 Earth Science PowerPoint Presentation
Download Presentation
Grade 8 Earth Science

Loading in 2 Seconds...

play fullscreen
1 / 72

Grade 8 Earth Science - PowerPoint PPT Presentation

  • Uploaded on

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.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Grade 8 Earth Science' - rubaina-manaf

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Chapters 14 & 16:

Atmosphere & Climate

info relating to the atmosphere
Info. Relating to the Atmosphere
  • Troposphere-
  • Ionosphere-

Where does weather occur?

Why does the frequency of radio stations break up?

ozone layer
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)…
water cycle words to know
Water Cycle Words to Know
  • What is a cycle?
  • Evaporation-


  • Condensation-
  • Precipitation-
movement of air
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
Wind Systems
  • The Prevailing Winds are caused by the rotation of the earth and the position of the continents.


  • 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:


Polar Zones-

Temperate Zones-


What is the difference


weather & climate?

el nino la nina
El Nino ~ La Nina

Some 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
Climatic Changes
  • Greenhouse Gases-
  • Global Warming (Climate Change)
chapter 17 ocean motion
Chapter 17: Ocean Motion

How do oceans affect you?

How do you affect oceans?

composition of 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.
surface currents
Surface Currents
  • Move water horizontally
  • Parallel to earths surface
  • Powered by winds


distribute equatorial heat to other areas of earth

ocean waves tides
Ocean Waves & Tides
  • Wave- rhythmic movement that carries energy through ________ or _______
  • Ocean Waves carry energy through _________
  • 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.

the seafloor
The Seafloor

Ocean Basin Features

  • Continental shelf-
  • Continental slope-
  • Abyssal plains-

Plate Boundary Structures

  • Mid ocean ridge-
  • trench
mining the ocean floor
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
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 ____________


Chapter 22: Sun-Earth-Moon System

planet earth data
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 revolution
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
  • Earth’s TILT on its axis causes the seasons
  • Hemisphere tilted toward the sun receives more hours of sunlight & direct rays
earth s moon
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 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
the solar system
The Solar System
  • Collection of planets & other objects that orbit the sun
  • Inner Planets (rocky, solid core)
  • Outer Planets (gaseous)
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.
  • 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?

  • 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

  • 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
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)
the sun
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
Features of the Sun
  • Sunspots, prominences, flares
    • All caused by the intense magnetic field of the sun
the milky way
The Milky Way
  • What you know as HOME
  • Spiral galaxy
doppler shift
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)