Geology PDF

Geology 1/8/25 Intro to earth science - Geosphere + rocks, minerals, everything from the bottom of my feet to the core - Hydrosphere + rivers, lakes, water in the air - Atmosphere + weather, - Biosphere + animals Reaccuring concepts in Earth Science - Heat + Wh...

Geology 1/8/25 Intro to earth science - Geosphere + rocks, minerals, everything from the bottom of my feet to the core - Hydrosphere + rivers, lakes, water in the air - Atmosphere + weather, - Biosphere + animals Reaccuring concepts in Earth Science - Heat + Where does it come from? The sun. Heat coming from space, heat also coming from interal to the earth + Heat also comes from radioactve decay, atoms that are radioactive will break down and release heat - Density + Equal mass, different volume + Equal volume, different mass + D = M/V :Mass, Volume - Gravity All three play a role on why the core is in te Earth - Different substances solidify at different temperatures - Crust, low density layer - Mantle, higher density rocks - Core, even higher density: Iron and Nickle - Heat effects the density of objects, the hotter something is, the less density that it has - Lava Lamp Analogy - Cold wax is denser then liquid and sinks - Wax expands as it is heated, rising as it becomes less dense then the liqiud - Wax cools as it reaches the top and sinks again ***CONVECTION Convection in the Mantle - Hot mantle rises, cooling as it reaches the surface - Cooled mantle is denser and sinks + Stable Mantle convection creates hotspots, such as Hawaii Convection in the Atmosphere  - Hot air rises, cooling and condesning into clouds - Cooler air is denser and sinks Imperical Observations - To show something that is unrefutable proof The Strengths of Science - It is based in facts + Physcial objects + Observations + Measurements - Hypothesises, thoeries, and laws must be testable + Data that disproves the hypothesis, thorey, law must bbe obtainable + Astronomy is a science, makes scientific predictions about phenonena + Astrology is not science, doesn't come up with hypothesis, or have provavble data - Gel 1/15 Main Seqeuence Star Stage - Fate of Low-Mass stars - Stars that have less than 1/2 mass of the sun - Burns slowly at relatively low temperatures - Not enough gravity to fuse helium and never becomes a red giant - After hydrogen runs out, star cools as a dwarf star Giant star - Helium + Helium make the carbon, which makes up the core of the star = The star is mostly made of Hydrogen, fusion occurs in the layer around the core = Fusion reactions from the core push everything out, and fusion reactions around the core also push everything out. So the layer that doesn't have anything fusing gets pushed out so the star gets bigger. Outer layers have cooled which gives star almost reddish color Fate of Intermediate-Mass stars (Like the sun) - Fate mass 0.5-8x mass of the sun - After nuclear fuel runs out, core collapses from gravity - Outer atmosphere is shed producing Plantary Nebula - Core becomes White Dwarf star Burnout, Death, and Stellar Remnents - Plantary Nebula  + - Stellar Remnants + Remnant core: Collapsed core of star after its outer layers are expelled + Remnant core: Dwarf star = From stars 0.5-8x mass of the sun = Gravity is higher in massive stars prodcuing smaller Dwarf stars + Balck Holes = Remnant of super massive stars whose core after supernove is => 3x the mass of the sun Fate of Massive stars - Star Mass is greater then 8x te mass of the sun + After nuclear fuel runs out, core collapses from gravity + Star collaspe triggers Supernova Gel 1/10 Limitations of Space - More diverity, more questions asked and studied - The personal backgrounds of the scientists shapes the questions and interpretations of data - Bias, your interests and personal experiances The Scientific Cycle - Hypothesis + Testable thesis Gel 1/13 Nuclear Fusion Steller Classification - Stars are classified based on + Luminosity, brightness + Color + Temperature Absolute Brightness - Stars intrinisic brightness - Deoends on: Size and energy Apparent brightness + Size, temperature, and distance from the earth + Polaris: super far away, 30x larger then the sun Star brightness - Low temperature, red - High temperature, blue flame + Hotter objects emit more light at all wavelengths + Hotter objects radiate a larger proportion of their energy at shorter wavelengths Hertzprung-Russel Diagrams - Star classification system + Giants and Supergiants = Very bright stars + Dwarf stars = Very faint star = size estimated by comparing brightness with stars of known size with the same surface temperature Molecular Cloud - Where stars are born - Dense regions of nebulae composed mostly of Hydrogen + Gravity pulls matter tigether = Center reaches extremely high temperatures forming a protostar Gel 1/17 Formation of Solar system - Origin of the Solar system + Solar Nebula Hypothesis = Gravity and collisions eventually produce planetesimals = Sun and planets formed from the same expansive interstellar gas and dust = Slowly rotating cloud collapses under gravity = As cloud shrink, temperature and rotation increases Stellar Nebula Hypothesis - Sun and planets formed from the same expansive interstellar gas and dust - Materials at the center where it is hottest because protostar -> Sun - Rotation produces flattened, rotating disk of metallic grains, icy clumps, and rocky material Protoplanets to Planets - As protoplanets get larger, they pull in material into their orbits until they are the only ones left, becoming planets with stable orbits - Collisions and gravitational interactions hurl some rocky protoplanets away from the Sun 1/22 Solar Nebula Hypothesis - Sun and planets formed from the same expansive interstelar gas and dust - Material in the center where it is becomes protostar -> Sun - Faster rotation produces flattened rotating - Gravity and collisions eventually produce planetesimals + Gravity of planetesimals pull material to itself increasing in size and becoming protoplanets Protoplanets to Planets - As protoplanets get larger, they pull in material in their orbits until they are they only thing left, becoming planets with stable orbits - Collisons and gravitational Inner Rocky Planets vs Outer Gas Giant (Jovian) Planets - Inner Rocky planets + Smaller + Higher desnity + Made up mostly of rock and metal + Solid surface + Atmosphere - Outer Gas Giant planets + Larger + Lower density + Made up of mostly hydrogen, helium, and hydrogen compounds + No solid surface + Atmosphere from solar nebula + Many moons + Has rings Formation of Rocky vs Gas Giant Planets - Solar nebula cools, materials condense - Iron, nickel, and other heavy elements condense at higher temperatures so they stay closer to the Sun - Gases and lighter compounds are pushed by the solar wind away from the Sun where they condense beyond the frost line - Solar wind, charged particales expelled from a star Formation of Planetary Layers - As the planet gravity increases, differentiation of layers occurs - Fe and Ni Earth - Started out homogenous - As it cooled, it seperated into layers based on density - Core = Dense nickle and iron  - Mantle = Less dense rocks - Crust = Even less dense, brittle rocky crust Summary - Intersetellar Cloud + Gravitational collaspe - Protoplanetary disk + Condesnsation, gas to solid - Metals and rocks - Gas, ice + Accretion + Nebular Capture = Terrestrial planets = Jovials Protoearth - No ocean or life + Bombaraded by meteorites + Initiallu had homogenous composition + Differentiates into core, mantle, crust Origin of the Atmosphere - Originated through outgassing + H2O, CO2, H2, N2, SO2 and other gasse rose to the surfce from the interior of Protoearth - Expelled Via volcanic processes to form early atmosphere - High methane, low o2 - Life is responding for raising o2 + Series of oxidation events + Great Oxidation event, about 2.45 billion years ago Origin of the Ocean - Outgassed water vapor fell as rain - First permanent oceans ,- 4 Billions years ago + We know that there are rocks that only form in the precense of water Geology 1/25 Eccentiricty: Shape of Earth's orbit - Earth orbit cycles between low and high eccentricty + Low eccentricity: = More circular orbit = Smaller year-round difference in amount of sunlight + Low evventricity: = More ellipic orbit  = Larger year-round difference in amount of sunlight Tilt - Earths cycle between small and large tilt + Small tilt: Smaller difference in seasonal sunlight per hemisphere + Large tilt: Larger difference in seasonal sunlight per hemisphere Precession: Earths Wobble - Earth cycles between when earth is turned towards the sun along withits orbit The near and fra side of the moon - The moon is rotating at the same speed as it revolves around the Earth - Thus, it always keeps one side facing the Earth Origin of the Moon: Giant Impact Synestia Hypothesis - Mars-size planet collided with Proto-Earth - Synthestia form from vaportized Protoearth and Mars sized planet - Material pulled into center forms the Earth - Core of the protoearth and Mars-sized planet merge to become Earths core - Leftover material condences to form Moon Asteroids - leftover planetismals - Most asteroids orbit the Sun between Mars and Jupiter + Known as the Astroid belt = About 24 asterods > 125 miles across = 1-2 million asteroids > 0.6 miles wide = Many million asteroids smaller Comets - The first American to discover a comet was Maria Mitchell - Loose collections of rocky material, dust, water ice, and frozen gases - Nucleas - small central body - Coma = icy componenets vaporizezed by the Suns heat - Tail = ionized gas and dust pushed away by ionized gas and electrons radiating from the sun Kuiper Belt - Kuiper Belt objects + Leftover planetismals that forms beyond the frost line Oort Cloud - Icy planetesimals - Form roughly sphereical shell around solar system 1/27 Meteoroids, Meteors, and Meteorites - Meteoroids + Small chunks of debris floating in space - Meteors + Meteoroids that enter Earths atmosphere - Meteorites - meteors that land on Earth Weathering - Mechanical Weathering (erosion) + Product is known as grains + Rocks physically reduced to smaller pieces by water, wind, and gravity + Loose grains transported by water, wind, or gravity Chemical Weathering - Rock dissolved and become suspended in water, gases, and acids