Earth Science MCA Review

1. Earth Science MCA Review

2. General Science Items to Review • Acids– ph under 7 (1 to 6.9 ph) • Lemon juice ph 2, Apple juice ph 4 • Bases– ph over 7 (7.1 to 14 ph) • Baking soda ph 9, Antacids ph 10 • Chemical Changes • Litmus paper • Turns Red under acidic conditions • Turns blue under basic conditions • Strong Acid + Strong Base = Water & Salt • HCL+NaOH = NaCl & H20

3. Mineral- naturally formed, inorganic solid that has a definite crystalline structure. Native element - A mineral that is made of only one element. Ex. Gold Minerals

4. You can determine the identity of a mineral by examining seven different properties. • Color - Impurities create color (can be due to air or water) • Luster - How a mineral reflects light (Metallic / Non-Metallic) • Metals conduct heat & electricity • Streak - color of a mineral in powdered form, True Color • Cleavage • Fracture • Hardness - mineral’s resistance to being scratched. • Density - Mass / Volume Mineral Identification

5. Rock cycle - series of processes in which a rock forms, changes from one type to another, is destroyed, and forms again. Rock Cycle

6. Igneous Rock • Igneous - forms when hot, liquid rock, or magma, cools and solidifies. • Composition – • Felsic - Light-colored igneous rocks • Less dense, High Silicon & Oxygen • Mafic - dark-colored igneous rocks • More Dense • Texture - affected by cooling time • Coarse – larger crystals, longer cooling • Fine – fine crystals, short cooling.

7. Sedimentary Rock • Sedimentary – rock pieces (sediment) that is pressed together in layers (strata). • Weathering & Erosion create sediment and deposit it on the surface of the Earth. • Preserves fossils well, with older layers being found on the lowest layers. Principle of Superposition - younger rocks lie above older rocks, if the layers have not been disturbed. Youngest Oldest

8. Metamorphic Rocks • Metamorphic- the structure, texture, or composition of rock is changed by heat or pressure. • Affects all three types of rock • Pressure from overlying rock • Heat from nearby magma

9. Earth Layers • Chemical Layers • Crust, Mantle, & Core • Physical Layers • Lithosphere – rigid layer (Graham Cracker) • Asthenosphere – soft layer causes Plates to move (marshmellow) • Mesosphere – middle layer • Outer Core – liquid iron core • Inner Core – solid iron core

10. Plate Tectonics • Continental drift - states that continents once formed a single landmass, broke up, and drifted to their present locations. (fossils provide evidence) • Sea-floor spreading - process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies.

11. Plate Tectonics • Plate tectonics- Earth’s lithosphere is divided into tectonic plates that move around on asthenosphere and change shape. • Movement occurs because of changes in the density within the asthenosphere. • Thermal energy in Earth heats crust • Heated rock expands, becomes less dense & rises to Earth’s surface • At surface it cools, becomes more dense & sinks

12. Plate Tectonics (Boundaries) • Convergent boundary - two tectonic plates collide • Continental-Continental: pushes crust up (mountains formed) • Continental-Oceanic: oceanic crust sinks below continental (volcanoes formed) (Subduction Zone) • Oceanic-Oceanic: one crust sinks below other (underwater volcanoes)

13. Plate Tectonics (Boundaries) • Divergent boundary - two tectonic plates separate • New sea floor forms (Mid-Ocean Ridges) • Transform boundary - two tectonic plates slide past each other horizontally (Earthquakes) • The San Andreas Fault in California is an example of a transform boundary.

14. Earthquakes • Fault – Break in Earth’s crust • Normal fault- Rock layers pulled apart • Hanging wall moves downward. • Reverse fault- Rock pushed together • Hanging wall to moves upward. • Strike-slip fault– Rock layers move horizontally. • Ex. San Andreas Fault

15. Seismic Waves • Seismic waves - energy traveling through the Earth away from an earthquake. • Body waves travel through Earth (P & S waves) • Surface waves travel on Earth’s surface • P (pressure, primary) waves- move rock back & forth • Fastest, First to be detected • Travel through solids, liquids, & gases • S (shear, secondary) waves - move rock side-to-side • Slower, detected second • Can’t travel through liquid • Surface waves– travel on surface • Travel slowly & are more destructive

16. Volcanoes • Magma - Molten rock within the Earth. • Lava - Magma that flows onto the Earth’s surface. • Non-explosive Eruptions • Most common • Produce calm flows of lava in huge amounts. • Can be on the ocean floor (new ocean floor) or on land • Explosive Eruptions • Less common • High water or silica magma

17. Weathering • Breaking down rock by physical or chemical processes • Mechanical - Breakdown of rock into smaller particles by physical means • Ice wedging, wind, water, plants, & gravity • Chemical – rocks breakdown due to chemical reactions • Acid rain, Rust, Acids in groundwater & living things.

18. Erosion & Deposition • Erosion - process by which soil and sediment are transported from one location to another. • Rivers, wind, rain, ice & snow cause erosion • Cutbank – eroded sediment, outside river bend • Deposition- eroded rock & soil that is left behind. • Point Bar – Deposited sediment, inside river bend

19. Water Cycle • Water Cycle - the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean. • Condensation, Evaporation, Percolation, Runoff, Precipitation • Purified Water – Evaporation, Condensation, & Infiltration remove impurities from water and naturally purify it

20. The Sun • The Sun is a medium sized star • Large ball of gas, mostly hydrogen and helium held together by gravity • Produces energy by Nuclear Fusion, Hydrogen to Helium & Energy • Earth’s Primary energy Source.

21. The Atmosphere • Atmosphere – mixture of gases surrounding Earth • 78% Nitrogen, 21% Oxygen • Air pressure greater near Earth’s surface • Energy in the Atmosphere • Radiation- Energy transfer as electromagnetic waves • Conduction - Energy transfer by Contact • Convection – Energy transfer by Circulation

22. The Greenhouse Effect • Greenhouse effect - gases in the atmosphere absorb heat energy from the sun and radiate it back to Earth. • Green house gases – Carbon Dioxide (CO2), Methane, & Ozone • Bad Ozone in Troposhpere • Good Ozone in Stratosphere • “Good up High, Bad Nearby” • Leading Causes • Cars & Factories (Fossil Fuels) • Cutting down Trees

23. Winds • Wind - movement of air caused by unequal heating of the Earth & air pressure differences • Convection Cells – circular patterns of air movement • Warm air rises at equator • Cold air sinks at poles

24. Earth’s Seasons • Tilt of the Earth (23.5°) causes the change of Earth’s Seasons • Solstice – axis tilted directly toward or way from Sun • shortest & longest days of year • Equinox – “Equal night” • 12 hours daylight & 12 hours darkness

25. Orbits • Orbit – Formed by net effect of Gravitational attraction & Inertia • Revolution – path around the Sun • 365 ¼ Days = 1 year • Rotation – on the Earth’s axis • 24 hours = 1 day

26. Weather • High Pressure = H • Low Pressure = L • Cold Front = Blue with points • Warm Front = Red with circles