Earth Science Fundamentals

• Note the use of present tense, active voice and direct delivery of information
• No conversational filler or pleasantries

Unit One: Nature of Science and the Scientific Method

• A well-designed investigation follows the scientific method.
• Independent variable: the factor you change in an experiment.
• Dependent variable: the factor you measure in an experiment.
• Control: a standard for comparison in an experiment.
• Constant: factors kept the same during an experiment.
• Repeat trial: replication of an experiment to ensure reliability
• Precision: the degree to which repeated measurements show the same result.
• Accuracy: the degree to which a measurement reflects the real value.
• Data tables and graphs display independent and dependent variables.
• Bar graphs represent discrete data.
• Line graphs represent continuous data.
• A testable question guides the investigation.
• A prediction forecasts the outcome.
• A hypothesis is a testable explanation.
• Data is evidence gathered.
• Analysis involves interpreting data.
• Discussion explains the results.
• A conclusion summarizes the findings.
• Observation: gathering information through senses.
• Inference: interpreting observations.
• Conjecture: a conclusion deduced by guesswork or insufficient evidence.

Unit Two: Astronomy

Scale size of Earth, Moon, & Sun; Gravity and Orbits

• Earth, Moon, and Sun have vastly different sizes.
• Evidence such as photographs from space proves Earth is round.

Newton’s Law of Gravitation

• Gravity is a force that attracts objects with mass.
• Factors affecting gravity: mass and distance.
• Larger masses result in stronger gravity.
• Shorter distances result in stronger gravity.

Revolution, Rotation, Moon Phases

• Revolution: orbital motion around another object. Rotation: spinning on an axis
• Earth's revolution period: 365.25 days.
• Earth's rotation period: 24 hours.
• Lunar month: ~29.5 days.
• Year: 365.25 days.
• Moon phases determined by the relative positions of the Earth, Moon, and Sun.
• Lunar cycle sequence: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Crescent.
• Waxing phases: Moon appears to grow.
• Waning phases: Moon appears to shrink.
• The Moon's rotation and revolution periods are the same.
• This synchronous orbit causes the same side of the Moon to always face Earth

Eclipses

• Solar eclipse: Moon passes between the Sun and Earth.
• Lunar eclipse: Earth passes between the Sun and Moon.
• Solar eclipses occur when the Moon blocks the Sun's light.
• Lunar eclipses occur when Earth blocks the Sun's light from reaching the Moon.
• Umbra: the darkest part of a shadow.
• Penumbra: the partial shadow around the umbra.
• Eclipse maps show the path of eclipses across Earth's surface.

The Solar System: The Earth and Her Neighbors

• Ptolemaic view: geocentric model.
• Copernican view: heliocentric model.
• Galilean view: supported the heliocentric model through observations.
• Heliocentric model: Sun-centered.
• Geocentric model: Earth-centered.
• Galileo observed phases of Venus.
• Galileo observed moons orbiting Jupiter.
• Planets are celestial bodies orbiting a star/sun. Dwarf planets are smaller and do not clear their orbit.
• Planet order in the Solar System: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
• Positive correlation: as one variable increases, the other increases. Negative correlation: as one variable increases, the other decreases.
• Planet mass affects gravity.
• Higher mass results in higher gravity.
• Weight is the force of gravity on an object.

Distance in Solar System and Milky Way Galaxy

• Astronomical unit (AU): the average distance between Earth and the Sun.
• Lightyear: the distance light travels in one year.
• A lightyear is used to measure vast distances.
• Speed of light: ~300,000 kilometers per second.
• A galaxy is a vast system of stars, gas, and dust held together by gravity.

The Goldilocks Effect

• Goldilocks zone/habitable zone: the region around a star where temperatures allow liquid water.
• Factors affecting planet temperature: distance from the star and atmosphere.

Unit Three: Earth’s Origin and Geological Time

• Branches of Earth Science: geology, oceanography, meteorology, astronomy, environmental science.
• Earth's spheres: lithosphere (crust and upper mantle), atmosphere (gases), hydrosphere (water), biosphere (living things).
• Divisions of time on the geological time scale are determined by significant geological and biological events.
• The geological time scale represents Earth's history and its major events.
• Fossil categories: body fossils, trace fossils, mold fossils, cast fossils, and true form fossils.
• Index fossils are widespread and existed for a limited time.
• Index fossils are used to date rock layers.
• The Principle of Uniformitarianism: geological processes operating today also operated in the past.
• The Principle of Uniformitarianism says the present is key to the past.
• The positioning of rock layers determines relative ages.
• Law of Superposition: in undisturbed rock layers, the oldest is at the bottom.
• Relative age: age compared to other rocks or events.
• Absolute age: numerical age determined by radiometric dating.
• Radioactive decay: unstable isotopes decay into stable isotopes.
• Half-life: the time it takes for half of the radioactive atoms to decay.
• Radioactive decay and half-lives determine the absolute age of rocks.

Unit Four: Minerals and Rocks

• Matter: anything that has mass and takes up space.
• Five phases of matter: solid, liquid, gas, plasma, Bose-Einstein condensate.
• Law of Conservation of Matter: matter cannot be created or destroyed, only changed.
• Physical change: alters the form of a substance, not its chemical identity.
• Melting ice is an example of a physical change.
• Chemical change: produces a new substance with different properties.
• Burning wood is an example of a chemical change.
• 5 characteristics every mineral possesses: naturally occurring, solid, definite chemical composition, ordered atomic arrangement, inorganic.
• Mineral identification tests: streak, hardness, luster, density, cleavage/fracture, color.
• Rocks are made up of one or more minerals.
• Rocks are identified by composition, texture, and origin.
• Three types of rocks: igneous, metamorphic, and sedimentary.
• Igneous rocks form from cooled magma or lava.
• Metamorphic rocks form from rocks altered by heat and pressure.
• Sedimentary rocks form from compacted and cemented sediments.
• The rock cycle illustrates the Law of Conservation of Matter.
• The rock cycle shows how rocks change from one type to another.
• Weathering: breaking down rocks.
• Erosion: moving broken-down rocks.
• Deposition: sediments accumulate.
• Igneous rocks form from magma or lava cooling and solidifying.
• Small crystals form from fast cooling.
• Large crystals form from slow cooling.
• Sedimentary rocks form from sediments compacting and cementing together.
• Conglomerates form from rounded gravel.
• Sandstone forms from sand.
• Limestone forms from marine organisms.
• Metamorphic rocks form when existing rocks are changed by heat, pressure, or chemical reactions.

Unit Five: Plate Tectonics/Earthquakes

• Earth's interior layers: crust, mantle, outer core, and inner core.
• Crust composition: oxygen, silicon, aluminum.
• Two types of crust: oceanic and continental.
• Oceanic crust: basalt.
• Continental crust: granite.
• Oceanic crust is denser than continental crust.
• Mantle composition: silicon, oxygen, iron, magnesium.
• Outer Core composition: liquid iron and nickel.
• Inner Core composition: solid iron and nickel.
• Lithosphere: rigid outer layer.
• Lithosphere is made up of the crust and uppermost part of the mantle.
• Asthenosphere: partly molten upper mantle below the lithosphere.
• Scientists used seismic waves to determine the shape and size of the core.
• Pangaea: a supercontinent that existed millions of years ago.
• Alfred Wegener's theory of continental drift: continents were once joined together.
• Evidence for continental drift: matching fossils, matching rock formations, glacial evidence, and continental fit.
• Scientists questioned the mechanism for continental drift.
• Plate tectonics explains how continents move.
• Plate tectonics: Earth's lithosphere is divided into plates that move.
• Major tectonic plates: Pacific, North American, Eurasian, African, Antarctic, Indo-Australian, South American.
• Convection in the mantle causes plate motion.
• Subduction: one plate slides beneath another.
• Sea-floor spreading: the formation of new oceanic crust at mid-ocean ridges.
• Magnetic striping proves sea-floor spreading.
• Rate of plate movement: distance/time.
• Three types of plate boundaries: convergent, divergent, and transform.
• Convergent boundary: plates collide.
• Divergent boundary: plates separate.
• Transform boundary: plates slide past each other.
• Mid-ocean ridges: underwater mountain ranges formed at divergent boundaries.
• Rift valleys: valleys formed on land at divergent boundaries.
• Trenches: deep ocean troughs formed at convergent boundaries where subduction occurs.
• Mountains: formed at convergent boundaries.
• Convergent boundaries: where plates collide, creating mountains, volcanoes, and trenches.
• Divergent boundaries: where plates separate, creating mid-ocean ridges and rift valleys.
• Transform boundaries: where plates slide past each other, creating faults.
• Island arc volcanoes: chains of volcanoes formed at subduction zones.
• Hot spots in oceans: areas of volcanic activity caused by mantle plumes.
• Mid-ocean ridges: formed by the interaction of divergent plates.
• Rift valleys: formed by the interaction of divergent plates.
• Trenches: formed by the interaction of convergent plates.
• Mountains: formed by the interaction of convergent plates.
• Faults: formed by the interaction of transform plates.
• Island arcs (like Japan): formed by the subduction of an oceanic plate under another oceanic plate.
• Coastal volcanoes (like in Washington and Oregon): formed by the subduction of an oceanic plate under a continental plate.
• Fault: a break in Earth's crust where movement occurs.
• Faults often occur at plate boundaries.
• Three types of stress in the crust: tension, compression, and shearing.
• Tension: pulling apart.
• Compression: squeezing together.
• Shearing: sliding past each other.
• Normal faults: tension stress.
• Thrust (reverse) faults: compression stress.
• Transform (strike-slip) faults: shearing stress.
• Earthquake: a sudden release of energy in the Earth's crust.
• Epicenter: the point on Earth's surface directly above the focus of an earthquake.
• Focus: the point beneath Earth's surface where an earthquake begins.
• Hanging wall: the block above the fault.
• Foot wall: the block below the fault.
• Three main types of seismic waves: P-waves, S-waves, and surface waves.
• P-waves: primary waves, compressional, travel through solids and liquids.
• S-waves: secondary waves, shear waves, travel through solids only.
• Surface waves: travel along Earth's surface, causing the most damage.
• Triangulation uses seismic waves to determine the epicenter of an earthquake.

Test your knowledge of fundamental Earth Science concepts. Topics include scientific experiments, Newton's Law of Gravitation, phases of the moon, models of the solar system, light-years, solar and lunar eclipses, minerals and rocks, and the Law of Conservation of Matter.