Geol-1_LE-1 PDF
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This document provides an overview of geology, covering topics like the scientific method, earth structure, and scientific models. The information is presented in a structured format that allows readers to examine a variety of geologic topics, such as the different layers of the earth.
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GEOLOGY - Can explain and predict. Geology Scientific Model - From the ancient Greek (gê) meaning - A precise representation of how a “earth” and (logia) meaning “study of”...
GEOLOGY - Can explain and predict. Geology Scientific Model - From the ancient Greek (gê) meaning - A precise representation of how a “earth” and (logia) meaning “study of” natural system is built or should behave. - It is a branch of natural science concerned with the Earth and other Earth’s Shape and Surface astronomical objects, the rocks of Geodesy which they are composed, and the other - Where the scientific method has roots. processes by which they change over - A very old branch of science that studies time. the Earth’s shape and surface. - It is a “science”, meaning that geological questions are investigated Columbus with deductive reasoning and scientific - Set a westward course for India. methodology. - He discovered the New World instead of the Spice Island. 4.5 billion years ago - Earth and other planets in the solar Eratosthenes system are formed. - Determine the size of the Earth. - A Greek librarian who lives in 3 billion years ago Alexandria, Egypt. - Living cells developed on Earth’s surface. Oblate Spheroid - Shape of the Earth. Earth System (Geosystem) - How we study our complex natural Earth As A System of Interacting world. Components - It involves many interacting components. Earth - Is an open system (exchange of mass Scientific Method and energy with the rest of the cosmos) - Where scientists all rely on. - General plan based on methodological Radiant Energy observations and experiments - Energy from the Sun. Parts of ScientificMethod - The primary source of energy on 1. Observation Earth. 2. Hypothesis - A tentative explanation based 5 Main Systems on data collected through - Solar radiation energizes these observations and experiments. components 3. Experimentations a. Geosphere 4. Analyze Data - The Earth itself. 5. Conclusion 6. Theory Development b. Biosphere e. Age - All organic matter is related to - Is the smallest hierarchical life near Earth’s surface. geochronological unit and is c. Hydrosphere equal to the chronostratigraphic - Surface waters comprise all stage. bodies of water. d. Atmosphere Earth’s Layer - Gaseous envelope extending Differentiation from Earth’s surface to an - Process of chemical composition altitude of about 100 km. segregation of the planet. e. Cryosphere - Forms the layers of the Earth. - Polar ice caps, glaciers, and other surface ice and snow. Seismic Waves - Greek word = seismos - Waves from Earth’s interior. Geologic Record - Can be recorded using a seismometer. - The information preserved in rocks formed at various times throughout Silicates Earth’s long history. - The entire planet was made out of this rock. Principle of Uniformitarianism - Formed by James Hutton Compositional Layer - “The present is the key to the past” a. Crust - The thinnest and outermost Geological Time Scale layer of the Earth. - Is a way of representing deep time based - Divided into two: Continental on events that have occurred throughout and Oceanic crust. Earth’s history, a time span of about 4.54 billion years. b. Mantle (silicate-rich rock) - The Largest layer Geochronological unit - The second compositional layer - The subdivision of geological time. has three parts: Upper, a. Eon Transitional, and lower - Equal to the chronostratigraphic mantle. eonothem b. Era c. Core (Iron and nickel) - Equal to the chronostratigraphic - Innermost layer. erathem - Thickest if considering outer c. Period and inner core. - Equal to the chronostratigraphic system d. Epoch Mechanical Layer - Equal to chronostratigraphic a. Lithosphere (Plates) series - The solid outer layer comprises a. Mohorovicic Discontinuity (Moho) the crust and uppermost - mantle and crust boundary. mantle. b. Gutenberg - Forms the tectonic plates. - Mantle-core boundary - Where magma can be found. c. Lehmann - Outer core and inner core b. Astesnosphere boundary - Located within the upper d. Conrad mantle. - Continental and oceanic crust - Weak ductile layer, beneath the boundary (not always present) lithosphere that deforms to e. Repitti accommodate the horizontal - The upper and lower mantle and vertical motion of the plates. Atmosphere - The primary source of magma a. Composition - 78% Nitrogen - 20% Oxygen c. Mesosphere (Deep Mantle) - 0.9% Argon - Solid rigid layer due to high - 0.04% Carbon dioxide pressure. - Others Note: between the mantle and the outer core a strange region called D double prime layer is Air identified. - Is a mixture of many discrete gases, - Thickness varies in different locations. each with its physical properties, in - This region is influenced by the activity which varying quantities of tiny solid of the lower mantle and outer core. and liquid particles are suspended. - Mantle Plumes—create large-scale basaltic volcanism—originated from Nitrogen and Oxygen here. - Make up 99% of the volume of clean dry air. d. Outer Core Argon - Only liquid layer. - Remaining 1% of clean dry air. - Responsible for the magnetosphere. Atmosphere Other Components a. Carbon Dioxide e. Inner Core - Influences the heating of the - A solid sphere (frozen due to atmosphere pressure) b. Water Vapor - Growing slowly - Source of all clouds and - The innermost layer. precipitation c. Aerosols Discontinuities - Tiny solid and liquid particles - Boundaries between layers of the that absorb, reflect, and scatter Earth’s interior. incoming solar radiation. d. Ozone decreases with an increase in - Absorbs much of the altitude. potentially harmful UV Tropopause — outer boundary of the radiation from the sun. troposphere. e. Human-generated pollutants - Airborne gases and particles b. Stratosphere that endanger health and/or - Temperature remains constant disrupt the functioning of the to a height of 20km then natural environment (carbon increases until it reaches the monoxide, nitrogen oxides. stratopause (50km). Sulfur dioxide, particulates, - Temperature increases because etc.) it is where the ozone is concentrated. Atmospheric Pressure - Heated as the ozone absorbs - The weight of the air above solar radiation. - Changes with altitude c. Mesosphere - The rate of pressure is not constant with - Third layer. altitude. - Temperature decreases with - Pressure decreases rapidly near the height until it reaches the Earth’s surface, gradually at greater mesopause (80km), -90 heights. degrees Celsius. Parts of the Atmosphere - The coldest temperature occurs in mesopause. d. Thermosphere - Fourth layer - Contains a tiny amount of atmospheric mass. - Has no well-defined upper limit. - 1000 degrees Celsius. e. Ionosphere - Layer that conducts electricity - Named after ions–energy particles created by sunlight and outer space. a. Troposphere - Reflect radio waves due to - Almost all weather develops in having no free electrons and the troposphere because it ions. contains almost all of water - Also, reflect solar vapor. winds—highly charged particles - Clouds, fog, thunderclouds, and ejected by the sun. cirrus. - Created the - The lowermost layer, in which “auroras”—northern and we live, where temperature southern lights. Guglielmo Marconi d. Sulfur - Father of Wireless e. Calcium - Proved the existence of the ionosphere. f. Others Turbopause - Fluctuating area between thermosphere Sea Surface Temperature and exosphere. - Near the Equator is equal to hot water, and Near the poles is equal to cold f. Exosphere water. - Expands and contracts as they - -2 degrees Celsius to 36 degrees Celsius come into contact with solar (17 degrees Celsius average) storms. - Temperature varies according to Exobase latitude. - The lowest level of the exosphere. Ocean gyres Earth-Sun Relationships - Large circular rotations of water Equinox - Caused by two different forces acting on - Equal nights water: wind and the Coriolis effect - Length of the day is 12 hours. - Rotates clockwise in the Nothern Solstice hemisphere - Days are shortest because the Sun’s - Rotates counterclockwise in the angle is at the lowest. Southern hemisphere Ocean Salinity Hydrosphere - Most oceans have a salinity of 34 ppt to - The total amount of water on the 36 ppt. planet (surface, underground, and air). - Salt makes seawater more dense than Water Cycle freshwater. - How water moves throughout the Earth. - High salinity and low temperature The Blue Marble make the ocean so dense. - Famous photograph of the Earth Water-world El Nino - What Earth is sometimes called. - Warm water, weak trade winds 3682 meters or 12080 feet La Nina - The average depth of the ocean. - Cool water, strong trade winds Mount Everest - Highest point on Earth Both are known as El Nino-Southern - 8848 meters above sea level Oscillation (ENSO). Challenger Deep - This cycle involves changes in the - Lowest point on Earth temperature of surface waters in the - 10900 meters below sea level tropical Pacific Ocean which impact atmospheric pressure and wind patterns Minerals in Ocean Water worldwide. a. Chlorine b. Sodium c. Magnesium Plate boundaries - Boundaries between plates. Movement of the Plate Boundaries a. Convergent (plate area increase) - Two plates collide, and one plate can be pushed under the other, causing mountain building, earthquakes, and volcanic activity. 1. Ocean-Ocean Convergence (trenches) Introduction to Plate Tectonics Theory 2. Ocean-Continent Convergence (Volcanic belt of Plate Tectonics mountains) - Describes the large-scale motion of the 3. Continent- Continent Earth’s surface Convergence (mountains & - Explains how the continents and oceans Plateau) are in constant motion, formed and b. Divergent (plate area decrease) reshaped over geological timescales. - Two plates move apart, allowing magma to rise and form new Alfred Wegener oceanic crust, as seen at - Proposed the continental drift theory. mid-oceanic ridges. Pangaea (all the Earth) 1. Continental Plate Separation - Supercontinent - Characterized by rift Supporting Evidence of Continental Drift valleys, volcanic Theory activity, and - Similar rock formations earthquakes. - fossils across continents 2. Oceanic Plate Separation - Continents are like puzzle pieces that fit - Marked by a mid-ocean together. ridge. - Centrifugal forces of the Earth (tilt of c. Transform (plate remains constant) the Earth) - Plates slide past each other, Supporting Evidence of Plate Tectonics causing earthquakes but no - Fit of the continents significant creation or - Fossil Distribution destruction of the Earth’s - Seafloor Spreading (Harry Hess and surface. Robert Dietz) - Volcanic and Earthquake Activity Magnetic Anomalies a. The location of volcanoes and - Magnetic field alternated between high earthquakes around the world and low values in long, narrow parallel coincides with the location of bands. tectonic plate boundaries. Magnetic Reversal - Changes in the orientation of the north 3 Main Evidence for Big Bang Theory and south poles are caused by changes 1. Abundance of Primordial Elements in geodynamo. (H and He) 2. Hubble’s Law Thermoremanent Magnetization - Suggest that “galaxies seem to - Rock remembers the magnetization long be moving away from us at a after the magnetizing field existing at speed proportional to their the same time it formed has changed. distance) - Supports early ideas that the Astronomical Positioning universe is expanding - Measuring positions of points on Earth’s a. Red Shift - light from the surface in relation to the fixed stars in galaxies is red-shifted because it the night sky. moves away from us. b. Doppler Effect - refers to how Global Positioning System we see waves when the object - Constellation of 24 Earth-orbiting creating the waves is moving satellites. towards or away from us. 3. Cosmic Microwave Background Rodinia Radiation - Earlier supercontinent than Pangaea. - Remnant heat of the universe. - Discovered by Arno Penzias Hotspots and Robert Wilson - Region of intense localized volcanism. (Radioastronomers). Applications of Plate Tectonics Alternative Theories - Geological Hazards 1. Steady-state theory (Fred Hoyle) - Resource Exploration - New matter is continuously - Climate Change created as the universe expands - Scientific Research thus adhering to the perfect cosmological principle. 2. Divine Intervention (Biblical Creation) Big Bang Theory - First proposed by the Belgian Priest Planetary Accretion George Lemaitre (1920). - Where small solid objects in space - Lead to a very rapid expansion or clump together by electrostatic forces to inflation of space, matter, and energy. form larger and larger objects with the Note: after hundreds of million years, matter aid of self-gravity. started to clump together and form protogalaxies, and inside them are Nebular Hypothesis (Immanuel Kant and Pierre first-generation stars. Simon de Laplace) - H and He are primary elements in stars - Theory of the origin of the Solar then carbon, oxygen, silicon, and iron System. through nuclear fusion. - The solar system originated from a single rotating cloud of gas and dust which contracted due to gravity starting 4.6 billion years ago. Other Objects in the Solar System Nebulae Asteroids - A form of cloud dust and gas clumped - Bodies of rock and metal range from together under self-gravity and meters to kilometers in terms of electrostatic forces then started rotating diameter. forming the stars. (Remaining matter Meteroids forms the planet) - Smaller than asteroids - Form from breaking of asteroids. Solar System Meteor Galaxy - When meteoroids enter the atmosphere. - Are gravitational-bound star systems, - Also called shooting stars collections of gas, dust, and billions of Fireball stars. - A very bright meteor similar to Venus. Stars Bolide - Are high-temperature gravitationally - If the meteor explodes. bound gas bodies with internal heat Meteorites derived mainly from nuclear fusion. - When the meteor lands on Earth. Note: Our solar system is a part of the Comets “Orion’s arm” of the Milky Way galaxy. - Large chunks of ice are found in the Terrestrial Planets Kuiper belt or Oort cloud. - Earth – the only planet that sustains life. - Mercury – Closest to the sun. - Venus – Hottest planet. Zircons - Mars – Red planet due to Iron. - A crystal that is believed where water on Jovian Earth originated from. - Jupiter – Largest planet. - Saturn – Ring planet The Moon Ice Giants Moon - Uranus – Third largest - 2nd brightest object in the sky. - Neptune – Farthest planet - Formed due to the collision of planet Asteroid Belt Theia to Earth called the Theia Impact - Divides terrestrial and jovian planets. or Giant-Impact Hypothesis. - Contains asteroids and dwarf planets as big as the Ceres planet. Other Theories of Moon Formation Kuiper Belt 1. Planetary Capture - Home of the dwarf planets; Pluto and - A passing planet is captured by Comets Earth’s gravity Oort Cloud 2. Sister Planetismal of Earth - Collection of icy debris - The moon is created alongside - Edge of the Solar System. Earth. 3. Parts of the Earth broke off due to fast spinning.