origin of earth and ocean scientific observations and explanations on the origin and evolution of...
TRANSCRIPT
Origin of Earth and OceanOrigin of Earth and OceanScientific Observations and Explanations Scientific Observations and Explanations
on the Origin and Evolution of Earth’s on the Origin and Evolution of Earth’s OceanOcean
GEOL100 - Physical GeologyGEOL100 - Physical GeologyRay Rector - Instructor
Preview of Preview of TopicsTopics Origin of the UniverseOrigin of the Universe Origin of the Solar SystemOrigin of the Solar System Origin of Earth-Moon SystemOrigin of Earth-Moon System Origin of the Ocean and AtmosphereOrigin of the Ocean and Atmosphere Origin of LifeOrigin of Life The Age of the EarthThe Age of the Earth
A Twisted COSMIC TimescaleA Twisted COSMIC Timescale
Starting with the Big Bang event 13.7 billion Starting with the Big Bang event 13.7 billion years ago, and evolving to the present day.years ago, and evolving to the present day.
The Visible and Invisible The Visible and Invisible UniverseUniverse
13.7 Billion Years of Creation and Destruction13.7 Billion Years of Creation and Destruction
The Basic The Basic ComponentsComponents
Expanding SpaceExpanding Space 4 Fundamental Forces4 Fundamental Forces Energy - EMREnergy - EMR MatterMatter Dark energyDark energy Dark MatterDark Matter
How Much Stuff Is Out How Much Stuff Is Out There?There?
Position in the sky and the extent of the magnification Position in the sky and the extent of the magnification
Hubble Deep Field ImageHubble Deep Field Image
Every spot of light is a galaxy!
The Rough Stats:The Rough Stats:1) Size1) Size: 30 x 10: 30 x 1099 cubic light cubic light
yearsyears 1x101x1066 light yrs between light yrs between
galaxiesgalaxies
2) Matter2) Matter: 100 billion galaxies: 100 billion galaxies 1.6 x 101.6 x 106060 kilograms kilograms
@ 1.4 kg per cubic meter@ 1.4 kg per cubic meter
3) Only3) Only 0.0000000000000000000042 % 0.0000000000000000000042 % of the universe contains any of the universe contains any mattermatter
It’s a SUPER empty place!It’s a SUPER empty place!
Survey of Elements Found in Survey of Elements Found in UniverseUniverse
Questions:Questions: 1) What processes made the elements? 2) Why the three-step, relative abundance distribution of the elements?
92 Naturally-occurring elements
Predominantly Hydrogen and Helium
Lots of Carbon, Nitrogen, Oxygen, Silica, Sulfur, and common metals
Minor amounts of rare earth and very heavy elements
BIG BANG Theory -BIG BANG Theory - 14 Billion Years of Cosmic 14 Billion Years of Cosmic
EvolutionEvolution
The Big Bang Elements:The Big Bang Elements: Hydrogen and Helium were the two Hydrogen and Helium were the two major elements generated in cosmically-massive amounts soon major elements generated in cosmically-massive amounts soon after the initial Big Bang event – very little else.after the initial Big Bang event – very little else.
?
The Fate of Our Universe?The Fate of Our Universe?
Possible OutcomesPossible Outcomes1) The Big Freeze1) The Big Freeze
Expand forever Cold and Dark
2) The Big Crunch2) The Big Crunch CollapseCollapse Prelude to BB#2?Prelude to BB#2?
3) The Big Rip3) The Big Rip Runaway dark energyRunaway dark energy Anti-gravity tears Anti-gravity tears
apart all matter apart all matter
Galaxies – Gigantic Star ClustersGalaxies – Gigantic Star Clusters
Galaxies are “island universes” Galaxies are “island universes” where stars are born, live and die where stars are born, live and die
Gravity is the controlling force on Gravity is the controlling force on galaxy formation and evolutiongalaxy formation and evolution
Universe contains roughly 100 Universe contains roughly 100 billion starsbillion stars
Typical galaxy contains 100 billion Typical galaxy contains 100 billion starsstars
A typical star located in a galaxy is A typical star located in a galaxy is much like our Sunmuch like our Sun
Stars generate new elements during Stars generate new elements during fusion and novafusion and nova
All elements except for the very All elements except for the very light ones can only form inside starslight ones can only form inside stars
Our galaxy – the Milky Way – looks Our galaxy – the Milky Way – looks very much like our neighbor – the very much like our neighbor – the Andromeda galaxy.Andromeda galaxy.
Andromeda Galaxy
Circus of Galaxies
Key Points:Key Points:
Our Very Own Island Our Very Own Island UniverseUniverse
Milky Way Galaxy is 100 Milky Way Galaxy is 100 million light in diametermillion light in diameter
Our galaxy contains Our galaxy contains roughly 400 billion starsroughly 400 billion stars
Sun is a very typical Sun is a very typical star located in one of star located in one of the arms of the Milky the arms of the Milky Way GalaxyWay Galaxy
Other planetary Other planetary systems have been systems have been found in our galaxyfound in our galaxy
We arehere
Milky Way GalaxyMilky Way Galaxy
Nebula – Star NurseriesNebula – Star Nurseries Nebula are regions of dense Nebula are regions of dense
hot gases, stellar debris, and hot gases, stellar debris, and very young starsvery young stars
New stars and planetary New stars and planetary systems form from the both systems form from the both primordial matter and the primordial matter and the remnants of exploded stars remnants of exploded stars within nebulawithin nebula
Our solar system most likely Our solar system most likely formed in a nebula much like formed in a nebula much like this onethis one
Condensation Theory for star Condensation Theory for star and planet formationand planet formation
Carina Nebula
Observed Stellar Systems in the Observed Stellar Systems in the MakingMaking
The Trifid Nebula
Observations of Newly Observations of Newly Forming Stars Within a Forming Stars Within a Nebula CloudNebula Cloud
The Nebula Condensation Theory best explains The Nebula Condensation Theory best explains the formation of stellar systems such as oursthe formation of stellar systems such as ours
Stellar Fusion – The Element Stellar Fusion – The Element FactoryFactory
1) Normal Star = Helium
3) Red Supergiant Star = Neon through Iron
2) Red Giant Star = Carbon
The Fusion Process
Note: Stellar fusion processes generate the light to medium weight elements: from Helium (He) all the way up to Iron (Fe).
Three-Stage Star EvolutionThree-Stage Star Evolution
Supernova – Heavy Element FactorySupernova – Heavy Element Factory
Supernova Process
Collapse of Red Supergiants
Tycho-supernova
Stellare Implosion – Explosion ProcessStellare Implosion – Explosion Process
Note: Supernova processes generate the medium- to heavyweight elements: from Iron (Fe) all the way up to Uranium (U)
We arehere
Our Solar Our Solar SystemSystem
4 Inner Planets
Mercury
Venus
Earth
Mars
4 Outer Planets
Jupiter
Saturn
Uranus
Neptune
What about
poor little Pluto?
The Nebula The Nebula Condensation Condensation
TheoryTheory
Animation1
Animation2
Origin of the MoonOrigin of the Moon
Multiple Theories
Twin Planet Theory
Moon Capture Theory
Earth-Birthed Theory
Giant Impact Theory
Most Likely Origin of the Moon
Giant Impact Theory
Impact Sequence of Earth and Mars-size Body
The Giant Impact Theory best explains formation The Giant Impact Theory best explains formation of the moon, based on physical and chemical dataof the moon, based on physical and chemical data
Density Differentiation of Young Density Differentiation of Young EarthEarth
Proto-earth was homogenous
Proto-earth underwent complete melting due to accretion energy and radioactive decay
Heaviest elements sank down to form core – mainly iron and nickel
Medium weight elements formed mantle and crust– mainly silicate minerals
Lighter elements floated up to form ocean and atmosphere
Early-stage Differentiation ModelEarly-stage Differentiation Model
Composition and Structure of EarthComposition and Structure of Earth
Five Chemically Distinct Layers
Eight Physically Distinct Layers
Formation of the Earth’s Formation of the Earth’s Ocean and Atmosphere Ocean and Atmosphere
1) The Origins of Earth’s Atmosphere and Ocean are Closely Tied Together
2) The Composition of the Atmosphere Has Greatly Changed Over the Last Four Billion Years
3) The Composition of Ocean Initially Changed Over the First Billion Years But Has Since Remained Stable
Evolution of Earth’s Evolution of Earth’s AtmosphereAtmosphere
Three StagesThree Stages1) Primordial Atmosphere ???
Hydrogen and helium from original condensed nebula
Probably stripped away by early solar wind and heating
2) Secondary Atmosphere
Volcanic outgassing of volatiles from inside planet
Primarily water and carbon dioxide with sulphuric and hydrochloric acid, and methane
No free oxygen – a nasty, poisonous, acidic mixture
3) Modern Atmosphere Modification of earlier atmosphere by life processes
Removal of carbon dioxide and enrichment of free oxygen
The Oxygen The Oxygen RevolutionRevolution
1)1) Photosynthetic marine Photosynthetic marine bacteria begin releasing bacteria begin releasing oxygen (Ooxygen (O22) into the ocean ) into the ocean and the atmosphere by 3 and the atmosphere by 3 billion years agobillion years ago
2) By about 2 billion years ago, sufficient 2) By about 2 billion years ago, sufficient OO22 in atmosphere to oxidize (rust) rocks in atmosphere to oxidize (rust) rocks
Protects Earth’s surface from ultraviolet solar radiationProtects Earth’s surface from ultraviolet solar radiation
Photosynthesizing Photosynthesizing CyanobacteriaCyanobacteria
3) Also by 2 billion years ago, protective ozone (O3) Also by 2 billion years ago, protective ozone (O33) layer ) layer
built up in atmospherebuilt up in atmosphere
4) By about 500 million years ago, O4) By about 500 million years ago, O22 levels in atmosphere levels in atmosphere
approach today’s levelsapproach today’s levels
Original Sources of Ocean Original Sources of Ocean WaterWater
Two Primary SourcesTwo Primary Sources
1) Volcanic Outgassing
Majority Amount of H20
2) Comet Impacts
Minority Amount of H20
Outgassing of Interior
Comet Strikes
Water initially collected from these Water initially collected from these two sources as part of a thick, dense two sources as part of a thick, dense atmosphere that later condensed and atmosphere that later condensed and precipitated into surface watersprecipitated into surface waters
Water from OutgassingWater from OutgassingMajority Primary Source = Volcanic Outgassing
Composition of volcanic gases for three volcanoes
Formation of Our OceanFormation of Our OceanThree Phase HistoryThree Phase History
1) Initially there was only water Initially there was only water vapor in atmospherevapor in atmosphere – Air and ground surface too hot for liquid
2) Cooling of atmosphere led to Cooling of atmosphere led to condensation and raincondensation and rain – Ground surface still too hot for pooling
3) Further cooling of ground Further cooling of ground surface finally led to the surface finally led to the accumulation of liquid water on accumulation of liquid water on surfacesurface – Ocean formed by 4 billion years ago
1)
2)
3)
The Twisted Geological The Twisted Geological TimescaleTimescale
Video Review of Big Bang to Present Day - YouTube
Timeline of Earth’s First Billion Timeline of Earth’s First Billion YearsYears
First Organisms
End of Bombardment
Oldest Existing Rocks
Formation of Ocean
Formation of Moon
Formation of Earth and Solar System
The Geological The Geological TimescaleTimescale
Key Ideas:Key Ideas: Originally based on Originally based on relative dating and relative dating and the use of age-the use of age-specific fossils specific fossils
Periods separated Periods separated by mass extinction by mass extinction events events
Numeric ages Numeric ages derived from derived from radiometric analysis radiometric analysis of igneous rocks of igneous rocks found within the found within the stratigraphic recordstratigraphic record
The Origin of Life on The Origin of Life on EarthEarth
Why Life on Earth? The Why Life on Earth? The ConditionsConditions
Mars
Venus
Did Life Did Life Start in the Start in the
Ocean?Ocean?
1) Earliest life forms found are 1) Earliest life forms found are fossilized bacteria in rocks fossilized bacteria in rocks dated 3.5 billion years old.dated 3.5 billion years old.
2) Found in both shallow and 2) Found in both shallow and deep ocean sedimentary deep ocean sedimentary rocks.rocks.
3) Exposed land surfaces back 3) Exposed land surfaces back then were barren and hellish.then were barren and hellish.
4) The ocean was much 4) The ocean was much milder, particularly the deep milder, particularly the deep ocean.ocean.
Stromatolites Microfossils
Conditions for Sparking Conditions for Sparking LifeLife
Lab ExperimentsLab Experiments1) Simulate early Earth conditions
2) Formed life-giving organic chemicals
3) No actual life created
4) Still an unsolved mystery
Comet Impacts?Comet Impacts?
5) Recent studies point to comet impacts
Most Likely Cradle for Life on Most Likely Cradle for Life on Earth?Earth?
Deep Sea Hydrothermal Vents?Deep Sea Hydrothermal Vents?
Warm, water-rich environment
Chemical-rich volcanic fluids
Protected from harsh surface
Class DiscussionClass Discussion
Review of Study Review of Study TopicsTopics
The Origin of Universe – The Origin of Universe – Energy and MatterEnergy and Matter
The Origin of the Solar SystemThe Origin of the Solar System Origin of Earth-Moon SystemOrigin of Earth-Moon System Origin of the AtmosphereOrigin of the Atmosphere Origin of the Ocean Origin of the Ocean Origin of the LifeOrigin of the Life
Preparation for Next Preparation for Next MeetingMeeting
Next Meeting TopicsNext Meeting Topics
1) Deep Time and The Age of Earth 1) Deep Time and The Age of Earth 2) Continental Drift Hypothesis2) Continental Drift Hypothesis 3) The Plate Tectonic Theory3) The Plate Tectonic Theory
Homework Assignment:Homework Assignment: Read Chapter 2 in Textbook Study the Instructor’s Website
@ www.geoscirocks.com Lecture Notes PowerPoint ER Videos 5 and 6
Continental Drift HypothesisContinental Drift Hypothesis
Alfred Wegener (1880-1930)