STAAR ReviewSTAAR Review

Category 3-Earth & SpaceStudents demonstrate an understanding of components, cycles, patterns, and natural

events of Earth and space systems.

Plate Tectonics History

1st: Wegener’s theory of Continental Drift—continents move slowly from Pangaea to present

2nd: Sea Floor Spreading—magma wells up forcing the sea floor apart & forming mid-ocean ridge (convection currents)

3rd: Theory of Plate Tectonics—Earth’s crust is broken into parts called plates that move or “float” on top of the mantle

8.9A

Sea Floor Spreading

8.9A

Sea Floor Spreading Evidence…

Rocks close to mid-ocean ridge are very young

age of rocks continues to increase the further away from the ridge

Iron bearing minerals record Earth’s magnetic field reversing

these rocks show same field direction equal distance either side of the mid ocean ridge

8.9A

Continental Plates

Plate Tectonics

Sea Floor SpreadingSea Floor Spreading

Subduction ZoneSubduction Zone

Trench-formed where one plate subducts

under another

Trench-formed where one plate subducts

under another

Transform Plate Boundary

Transform Plate Boundary

Divergent Plate Boundary

Divergent Plate Boundary

Convergent Plate Boundary

Convergent Plate Boundary

8.9B

Rift Valley • long, deep valley bound by normal faults

• forms where Earth’s crust being pulled apart

• can appear on land or beneath bodies of water, where two plates are separating

• on ocean floor between mid-ocean ridges, where new ocean crust is forming.

8.9B

1. Explain the history leading up to the Theory of Plate Tectonics.

2. Describe how plate movements create crustal landforms.

Topographic MapsTopographic Maps

• Show elevation• Uses contour lines• Can be used to identify landforms

• Show elevation• Uses contour lines• Can be used to identify landforms

Satellite View

Satellite View

Earth’s Rotation

rotates (spins) on its axis

rotates counter-clockwise

takes ~24 hrs per rotation

gives us day & night.

8.7A

Earth’s Revolution orbits around the sun

takes 365.25 days

axis tilt and revolution causes seasons

8.7A

The Moon

• Rotates on its axis once every 29.5 days

• Revolves around the Earth once every 29.5 days

• Therefore, we always see the same side of the moon

• Moon revolves counterclockwise

8.7B

Moon Phases

• We see the moon because it reflects light from the sun

• phases caused by moon’s revolution around the Earth

• phases are named for the lit portion of the moon

• Waxing = getting lighter; Waning = getting darker

• Crescent & Gibbous refer to the shape of the light being reflected

New Moon = no reflected light

Full Moon = full circle of reflected

light

8.7B

What Comes Next?

1. What phase comes immediately after a full moon?

2. Which position would you find it?

8.7B

Tides

• Spring Tides = higher high tides & lower low tides than average– Sun-Moon-Earth are aligned

• Neap Tides = lower high tides & higher low tides than average– Sun-Earth-Moon at right angle

• Caused by gravitational pull of Sun & Moon

• Moon is much closer & has more influence

8.7C

8.8A

HR Diagram

8.8A

1. Brightest star?

2. Hottest star?

3. Smallest star?

4. Name a …

…red supergiant

…white main sequence

…white dwarf

The Milky Way GalaxyThe Milky Way Galaxy

• What units would you use to measure the distance from our Sun to the center of our galaxy?

You are here.

8.8B, 8.8D

Universal KnowledgeUniversal Knowledge

1. Rotation causes _?_.2. Seasons are caused by _?_.3. Spring tides occur in what moon

phases?4. List the components of the universe

from smallest to largest.5. Name two things about stars that we

can get from a Hertzsprung-Russel Diagram.

1. Rotation causes _?_.2. Seasons are caused by _?_.3. Spring tides occur in what moon

phases?4. List the components of the universe

from smallest to largest.5. Name two things about stars that we

can get from a Hertzsprung-Russel Diagram.

Reminders…• Plate tectonics is the movement of

crustal plates which alters landforms: formation of rift valleys, mountain building, and other landform changes

• The moon goes through a cycle of changes both visually (phases) and forces acting on the Earth (tides)

• The Universe is made of many parts including nebulae, stars, planets, and moons

• Distance in the universe are measured in light-years.

»Any questions???