2. The Universe and the Earth PDF

Distribution of these lecture materials (electronic or hardcopy), in part or in whole, is strictly prohibited without prior written permission from the faculty of NIGS, UP Diliman. Any unauthorized use of these materials shall be subject to disciplinary action st...

Distribution of these lecture materials (electronic or hardcopy), in part or in whole, is strictly prohibited without prior written permission from the faculty of NIGS, UP Diliman. Any unauthorized use of these materials shall be subject to disciplinary action st (1 Semester, AY 2024-2025).  NASA (2024) 2: The Universe and the Earth Geol 11: Principles of Geology 1st Sem, AY 2024-2025 Kirk Justin S. Ramos Objectives  Discuss the Big Bang Theory on the origin of the universe  Explain the formation of the solar system using the Nebular Hypothesis  Discuss the different Earth layers, its composition and evidence for the layers  Explain the different theories of isostasy  Describe the features of the Earth Geol 11 1S AY2425 | The Universe and the Earth 2 Topics I. Formation of the Universe and the Earth II. Features of the Earth Geol 11 1S AY2425 | The Universe and the Earth 3 Topics I. Formation of the Universe and the Earth A. The Big Bang Theory B. The Nebular Hypothesis C. The Iron Catastrophe D. Giant Impact Hypothesis E. Formation of the Atmosphere II. Features of the Earth Geol 11 1S AY2425 | The Universe and the Earth 4 Formation of the Universe and the Earth Singularity An infinitely small region of space with zero volume and no dimensions State of the universe before the Big Bang Geol 11 1S AY2425 | Formation of the Universe and the Earth 5 A. The Big Bang Theory First proposed by Georges Lemaître in 1920s The Big Bang 13.8 Ga (billion years ago) Not an explosion of fire but a “superfast inflation or expansion“ in 3 dimensions Wright (1998) Geol 11 1S AY2425 | Formation of the Universe and the Earth 6  13.8 billion yrs. © The Birth of the Universe, The Kingfisher Young People‘s Book of Space Evidence of the Big Bang 1. Abundance of primordial elements (H and He) 2. Cosmic Microwave Background (CMB) Radiation 3. Hubble’s Law Geol 11 1S AY2425 | The Big Bang Theory 9 Evidence of the Big Bang 1. Abundance of primordial elements (H and He) 2. Cosmic Microwave Background (CMB) Radiation 3. Hubble’s Law Geol 11 1S AY2425 | The Big Bang Theory 9  13.8 billion yrs. © The Birth of the Universe, The Kingfisher Young People‘s Book of Space 2. Cosmic Microwave Background (CMB) Radiation 1965: astronomers tried to eliminate background “noise” from satellite signals o Leftover radiation NASA (2012) from the energy-rich Big Bang Geol 11 1S AY2425 | Evidence of the Big Bang 11 3. Hubble’s Law Edwin Hubble observed a “redshift” in 1929 o Redshift: stretching of wavelength when a light source moves away from an observer NASA (2012) Geol 11 1S AY2425 | Evidence of the Big Bang 12 The Observable Universe Present diameter: ~ 93 billion light-years (1 light year = 9.4607 x 12 10 km) o Rate of expansion: 1.96 million km per sec (6.5 times faster than the speed of light in vacuum) Geol 11 1S AY2425 | The Big Bang Theory 8  13.8 billion yrs. © The Birth of the Universe, The Kingfisher Young People‘s Book of Space B. The Nebular Hypothesis Immanuel Kant and Pierre Simon de Laplace, 18th century Rotating gas-dust cloud began to contract due to gravity o Most mass in the center -> Sun o Remaining matter -> asteroids -> planetesimals -> planets © redOrbits.com Geol 11 1S AY2425 | Formation of the Universe and the Earth 14 Nucleosynthesis Formation of new elements due to fusion in the Sun and other stars Process that creates new atomic nuclei from preexisting nucleons, primarily protons and neutrons © planetfacts.org Geol 11 1S AY2425 | The Nebular Hypothesis 15 Nucleosynthesis Supernova Explosion of a star o When a star burns all of its H and He fuel, it will collapse into itself then rapidly rebound outwards © space.com Geol 11 1S AY2425 | The Nebular Hypothesis 16  13.8 billion yrs. © The Birth of the Universe, The Kingfisher Young People‘s Book of Space The Solar System by Size Geol 11 1S AY2425 | The Nebular Hypothesis 18 Protosun and the Planets © physics.fortlewis.edu Terrestrial Planets Jovian Planets Rocky composition: largely Gaseous or liquid form silicate rocks and metals (Si, Fe, Composed of light elements (H, O) He, Ar, C, O, N) Geol 11 1S AY2425 | The Nebular Hypothesis 19 C. The Iron Catastrophe Formation of a differentiated Earth 1. Accretion - sticking together of dust due to gravity o Proto-Earth: dust ball 2. Heating -> melting of materials o Molten Earth 3. Differentiation – sinking of heavy elements, rising of light elements -> different composition on the center and at the surface o Differentiated Earth Cotham (2016) Geol 11 1S AY2425 | Formation of the Universe and the Earth 20 Sources of Heat Producing the molten Earth 1. Collision 2. Solar Radiation 3. Radioactive Heat 4. Temperature Increase from Contraction © study.com © Alan Doolittle © ISNAP Geol 11 1S AY2425 | The Iron Catastrophe 21 D. Giant Impact Hypothesis Collision of Earth with a Mars- sized planetesimal to form the Moon Foster (2016) © University of Oregon Geol 11 1S AY2425 | Formation of the Universe and the Earth 22 E. Formation of the Atmosphere 3.5 Ga 4.5 Ga onwards 4.0 Ga outgassing / venting / degassing Manilapai (2022) Geol 11 1S AY2425 | Formation of the Universe and the Earth 23 Topics I. Formation of the Universe and the Earth II. Features of the Earth A. Layers of the Earth B. Theories of Isostasy C. Size of the Earth D. Large Scale Features Geol 11 1S AY2425 | The Universe and the Earth 24 A. Layers of the Earth Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Features of the Earth 25 A. Layers of the Earth Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Features of the Earth 25 Layering by Chemical Composition 1. Core Fe-rich sphere with small amounts of Ni and other elements Fe-Ni alloy Radius: ~ 3 500 km ~ 16% of Earth’s volume ~ 31% of Earth’s mass Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Layers of the Earth 26 Layering by Chemical Composition 2. Mantle Still Fe-rich compared to crust, but diluted with O, Si, Mg, etc. Thickness: ~ 2 900 km ~ 83% of Earth’s volume ~ 68% of Earth’s mass Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Layers of the Earth 27  Element Weight % Layering by Chemical Composition O Si 46.6 27.7 Al 8.1 3. Crust Fe 5.0 Ca 3.6 Solid outer shell Na 2.8 K 2.6 Varying thickness: Mg 1.5 o Continental: 15 – 60 km o Oceanic: 3 – 15 km Less than ~ 1% of the Earth’s mass and volume Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Layers of the Earth 28 Layering by Mechanical Properties 1. Inner Core – solid 2. Outer Core – liquid 3. Lower Mantle – solid 4. Asthenosphere – solid but mobile 5. Lithosphere – solid and rigid Lithospheric Mantle Crust Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Layers of the Earth 29 Layering by Mechanical Properties Cause: response of each layer to a dominant variable at a certain depth Temperature increase -> melting Pressure increase -> solidification Tarbuck and Lutgens (2017) Geol 11 1S AY2425 | Layers of the Earth 30 Evidence of Earth Layering 1. Seismic Waves a. P-waves – both solid and liquid medium b. S-waves – solid medium Shadow zones – no waves or only certain waves recorded Geol 11 1S AY2425 | Layers of the Earth 31 Evidence of Earth Layering 2. Xenoliths - mantle rocks entrained by ascending magma and brought up to the surface © earthsci.org Farris and Paterson (2007) Geol 11 1S AY2425 | Layers of the Earth 32 Evidence of Earth Layering 3. Abundance of Fe in the Solar System Cotham (2016) Geol 11 1S AY2425 | Layers of the Earth 33 Evidence of Earth Layering 4. Earth’s magnetic field – generated by the flow of the liquid outer core Colvin (2021) © nagwa.com Geol 11 1S AY2425 | Layers of the Earth 34 B. Theories of Isostasy Isostasy Equilibrium between the lithosphere and asthenosphere Explains why topographic differences exist Theories 1. Pratt’s Theory 2. Airy’s Theory 3. Flexural Theory Geol 11 1S AY2425 | Features of the Earth 35 1. Pratt’s Theory Assumption: Equal depth of the lithosphere Elevation Differences: Due to differences in density Low density High density Lumongsod (2020) Geol 11 1S AY2425 | Theories of Isostasy 36 2. Airy’s Theory Assumption: Equal density Elevation Differences: Due to depth of roots o Deep root -> high elevation o Shallow antiroot -> low elevation Equal density antiroot root Lumongsod (2020) Geol 11 1S AY2425 | Theories of Isostasy 37 3. Flexural Theory Accounts for the elasticity of the lithosphere Local load -> regional downwarping o Example: ice sheets Lumongsod (2020) Geol 11 1S AY2425 | Theories of Isostasy 38 C. Size of the Earth Eratosthenes, 240 BC – first to measure Earth’s circumference Actual Circumference Equatorial = 40 076 km Lee (2005) Polar = 40 008 km Geol 11 1S AY2425 | Features of the Earth 39  D. Earth's Large Scale Features 1. Continents a. Mountain Belts b. Plains 2. Ocean Basins a. Mid-oceanic Ridges b. Trenches c. Abyssal Plains Geol 11 1S AY2425 | Features of the Earth 40 Modified from mapswire.com  D. Earth's Large Scale Features 1. Continents a. Mountain Belts b. Plains 2. Ocean Basins a. Mid-oceanic Ridges b. Trenches c. Abyssal Plains Geol 11 1S AY2425 | Features of the Earth 42 Mountain Belts Bands of high elevation above sea level (on land) NASA (2013) Geol 11 1S AY2425 | Continents 43 Modified from mapswire.com Plains Extensive areas of low elevation above sea level (on land) Dastrup (2019) © britannica.com Geol 11 1S AY2425 | Continents 45  D. Earth's Large Scale Features 1. Continents a. Mountain Belts b. Plains 2. Ocean Basins a. Mid-oceanic Ridges b. Trenches c. Abyssal Plains Geol 11 1S AY2425 | Features of the Earth 46 Mid-Oceanic Ridges Extensive ranges of high elevation below sea level (in the ocean) © Geo Journey © University of Hawaii Geol 11 1S AY2425 | Ocean Basins 47 Modified from mapswire.com  Trenches Deep regions of the ocean floor Features formed in subduction zones © britannica.com © Woods Hole Oceanographic Institution Geol 11 1S AY2425 | Ocean Basins 49 Modified from mapswire.com Continental Margin Features Landforms in the transition zone between continents and ocean basins a. Continental Shelf b. Continental Slope c. Continental Rise © IAS Gatewayy Geol 11 1S AY2425 | Ocean Basins 51 Seafloor Features Abyssal plains – vast, flat expanse of ocean floor Seamounts – submarine volcanic landforms Guyots – underwater plateaus from inactive seamounts © ussjpkennedyjr.org Geol 11 1S AY2425 | Ocean Basins 52 Reference Tarbuck, E. J., Lutgens, F. K., & Tasa, D. (2017). Earth: An introduction to physical geology. Pearson. Geol 11 1S AY2425 | The Universe and the Earth 53