energy drives earthquakes and volcanic eruptions drives earthquakes and volcanic eruptions...
Post on 02-Jan-2016
218 Views
Preview:
TRANSCRIPT
Energy Energy
Drives Drives earthquakes and earthquakes and volcanic eruptionsvolcanic eruptions
Concentrated at Concentrated at certain tectonic certain tectonic settingssettings
Associated with Associated with the Earth’s the Earth’s formationformation
Driving Forces on and Driving Forces on and within the Earth?within the Earth?
Heat formation: Heat formation: – Impact of asteroids and comets in Impact of asteroids and comets in
Earth’s early historyEarth’s early history– Decay of radioactive elementsDecay of radioactive elements– Gravitational contractionGravitational contraction– Differentiation into layersDifferentiation into layers
Driving Forces within the EarthDriving Forces within the Earth
Artist Impression, NASA
Earth’s internal heatEarth’s internal heat– Flows within the mantle (largest volume Flows within the mantle (largest volume
of Earth)of Earth)– Release in terms of volcanic activity and Release in terms of volcanic activity and
earthquakesearthquakes– Long-term: continents, oceans and Long-term: continents, oceans and
atmosphereatmosphere– Movement of tectonic platesMovement of tectonic plates
Driving Forces on and within Driving Forces on and within the Earth?the Earth?
Greg Houseman, University of Leeds
GravityGravity: the attraction between : the attraction between bodiesbodies– Segregating elements within the EarthSegregating elements within the Earth– Movement along the Earth’s surfaceMovement along the Earth’s surface
landslideslandslides
– Movement within the EarthMovement within the Earth Subducting oceanic slab moving into the Subducting oceanic slab moving into the
mantlemantle
Driving Forces on the EarthDriving Forces on the Earth
Landslide, China
The SunThe Sun– ¼ of the Sun’s energy reaches the Earth¼ of the Sun’s energy reaches the Earth– Evaporation Evaporation – Warming of atmosphere and Warming of atmosphere and
hydrospherehydrosphere– Weather: movement of air from warm to Weather: movement of air from warm to
cooler areascooler areas
Driving Forces on the EarthDriving Forces on the Earth
Formation of Solar SystemFormation of Solar System
What happened in the past and how What happened in the past and how is this currently reflected?is this currently reflected?– Gravitional forceGravitional force– Variations of temperaturesVariations of temperatures– RotationRotation– Composition of materialComposition of material– Different states of matterDifferent states of matter
A nebula is formed from A nebula is formed from a collection of gases a collection of gases (98%) and dust (2%) (98%) and dust (2%)
The mass rotates and is The mass rotates and is held together by held together by gravity.gravity.
The Nebular HypothesisThe Nebular Hypothesis
The solar system formation
Where do we see this in our Where do we see this in our sky?sky?
Third star down Third star down on Orion’s belton Orion’s belt
Star nurseryStar nursery 100 light years 100 light years
across (1 light across (1 light year equals 6 year equals 6 trillion miles)trillion miles)
Reflection of dust Reflection of dust and hydrogenand hydrogen
Orion ConstellationOrion Constellation
Winter sky Winter sky constellationconstellation
Hunter in Greek Hunter in Greek mythologymythology
New stars in New stars in several hundred several hundred million yearsmillion years
Nebula: Step INebula: Step I
Nebula exists and Nebula exists and through time:through time:– Contracts causing Contracts causing
the nebula to the nebula to increase increase temperature in temperature in center and increase center and increase speed of rotationspeed of rotation
The Nebula The Nebula collapses: step collapses: step
22
The collapsed The collapsed mass forms a mass forms a proto-sun and proto-sun and disc-shape disc-shape rotating mass of rotating mass of gas and dust.gas and dust.
The Orion nebula The Orion nebula contains about 153 contains about 153 visible visible protoplanetary disksprotoplanetary disks
2-17 times larger 2-17 times larger than our solar than our solar systemsystem
Rotation increasesRotation increases Temperature increases: 1,800,000 degrees Temperature increases: 1,800,000 degrees
FahrenheitFahrenheit Fusion beginsFusion begins
Protosun
FusionFusion
What does “to fuse” mean?What does “to fuse” mean? Remember, what is the composition Remember, what is the composition
of the nebula?of the nebula? Look on the periodic tableLook on the periodic table What is the relation or difference What is the relation or difference
between Hydrogen and Helium?between Hydrogen and Helium? Can you predict what fuses?Can you predict what fuses?
FusionFusion
Hydrogen (1 proton) fuses with Hydrogen (1 proton) fuses with another Hydrogen (1 proton) = another Hydrogen (1 proton) = Helium (2 protons)Helium (2 protons)
E = mcE = mc22
E = energyE = energy m= mass (very small)m= mass (very small) c squared =speed of light c squared =speed of light
(186,000 miles/second)(186,000 miles/second)
Step 3: Sun FormsStep 3: Sun Forms
The disk is The disk is “cleared out” due “cleared out” due to the immense to the immense amount of energy amount of energy released.released.
Dust and gases Dust and gases cool, condense cool, condense and accrete and accrete forming forming planetesimals.planetesimals.
Defined orbits Defined orbits around the sunaround the sun
Earth’s internal heat from Earth’s internal heat from formation
Our Our Sun
Collapsed disk not shownCollapsed disk not shown Sun is about 5 billion Sun is about 5 billion
years oldyears old 5 billion years until a red 5 billion years until a red
giant is formedgiant is formed
Temperature Temperature differences with differences with respect from the respect from the sunsun
Terrestrial planets Terrestrial planets (closer)(closer)
Jovian or gaseous Jovian or gaseous planets (farther planets (farther away)away)
Step 4: Material Cools and Step 4: Material Cools and Condenses; planet Condenses; planet
formationformation
Solar SystemSolar System
The first four planets are terrestrial The first four planets are terrestrial (iron and silicate)(iron and silicate)
The last planets are composed of The last planets are composed of gasesgases
Moon’s Moon’s FormationFormation
A large size planet , A large size planet , thought to be the thought to be the size of Mars, size of Mars, collided with Earth- collided with Earth- 4.4 billion years ago4.4 billion years ago
The debris formed The debris formed the moonthe moon
The impact, set the The impact, set the Earth on its axis Earth on its axis
23 degrees23 degrees
5:20
The Earth tilted on its axis in response to the collision
The Early EarthThe Early Earth
Hot Hot HomogenousHomogenous Crust as we know it, Crust as we know it,
not developednot developed 4.6 billion years ago4.6 billion years ago Melted again due to Melted again due to
the collision of the the collision of the Mars size planetMars size planet
Transitional EarthTransitional Earth
Segregation of Segregation of elements by densityelements by density
Iron moves to the Iron moves to the centercenter
Gravitational pull Gravitational pull and rotation and rotation
Chemically distinct Chemically distinct layerslayers
Crust: oxygen and Crust: oxygen and silicon (70%)silicon (70%)
Mantle: iron, Mantle: iron, magnesium, lower % magnesium, lower % Si, OSi, O
Core: iron and nickelCore: iron and nickel
Physically Distinct LayersPhysically Distinct Layers
Inner core: solidInner core: solid Outer core: liquidOuter core: liquid Mantle: capable of Mantle: capable of
flowflow Asthenosphere: Asthenosphere:
acts like a hot acts like a hot plasticplastic
Lithosphere: rigidLithosphere: rigid
LithosphereLithosphere
Rigid layer that lies between the Rigid layer that lies between the surface and 60-100 milessurface and 60-100 miles
““Floats” on the asthenosphereFloats” on the asthenosphere The tectonic plates are composed of The tectonic plates are composed of
lithospherelithosphere
Contains crust and upper mantleContains crust and upper mantle
Lithosphere
Continental Continental CrustCrust
Less denseLess dense Higher % of silicon Higher % of silicon
and oxygenand oxygen Lower % of iron Lower % of iron
and magnesiumand magnesium Thicker (15-25 Thicker (15-25
miles)miles) 30 % of Earth’s 30 % of Earth’s
surfacesurface
Oceanic CrustOceanic Crust
More denseMore dense Higher % of iron Higher % of iron
and magnesiumand magnesium Lower % of silicon Lower % of silicon
and oxygenand oxygen Thinner (5-7 miles)Thinner (5-7 miles) 70 % of Earth’s 70 % of Earth’s
surfacesurface
AsthenosphereAsthenosphere
Relatively soft layer capable of flow Relatively soft layer capable of flow that lies below a depth of 60-100 that lies below a depth of 60-100 miles (upper mantle)miles (upper mantle)
Dr. Railsback, University of Georgia
The MantleThe Mantle
Largest portion of the EarthLargest portion of the Earth Very rich in iron and magnesiumVery rich in iron and magnesium Very poor in silicon and oxygenVery poor in silicon and oxygen The mantle is solid but because of The mantle is solid but because of
high temperatures and pressures, it high temperatures and pressures, it is soft enough to flowis soft enough to flow
The The asthenosphereasthenosphere is part of the is part of the upper mantleupper mantle
The CoreThe Core
Outer core-liquid which can flow and Outer core-liquid which can flow and generates the Earth’s magnetic generates the Earth’s magnetic fieldfield
Inner core- solid and rotates faster Inner core- solid and rotates faster than the Earththan the Earth
Mostly iron, some nickelMostly iron, some nickel
Complex fields in the core contribute to the dipole field at the surface (UC Berkeley)
The magnetic field protects The magnetic field protects the Earth from solar the Earth from solar
radiationradiation
External Source of Earth’s External Source of Earth’s WaterWater
The collision of The collision of comets with the comets with the Earth’s surfaceEarth’s surface
As the ice hits the As the ice hits the warm Earth, the ice warm Earth, the ice melts to watermelts to water
Gravity holds the Gravity holds the water to the water to the surfacesurfaceHaley’s comet contains ices
and dust. The tail is created by ice to sublimate to steam.
Water vapor is Water vapor is released during released during volcanismvolcanism
Cooling of the hot Cooling of the hot Earth involved Earth involved intense volcanismintense volcanism
Water condensesWater condenses
Internal Source of Earth’s Internal Source of Earth’s WaterWater
Formation of AtmosphereFormation of Atmosphere
Gas is expelled Gas is expelled from magma during from magma during volcanic eruptionsvolcanic eruptions
Nitrogen, carbon Nitrogen, carbon dioxide, hydrogen, dioxide, hydrogen, sulfur dioxide and sulfur dioxide and waterwater
Early Earth’s Early Earth’s atmosphere did atmosphere did not contain which not contain which gas? Why?gas? Why?
History of the History of the EarthEarth
4.6 billion years old4.6 billion years old 4.4 bya, formation of moon4.4 bya, formation of moon 3.9 bya, oldest rock (sedimentary rock)3.9 bya, oldest rock (sedimentary rock)
– sedimentary rocks are made-up of sedimentary rocks are made-up of fragments of preexisting rocksfragments of preexisting rocks
– Sediments are carried and deposited by Sediments are carried and deposited by water and windwater and wind
– implies the existence of weather and implies the existence of weather and waterwater
4.1 bya, age of particles within the 4.1 bya, age of particles within the sedimentary rocksedimentary rock
Early Earth
3.5 bya, first bacteria3.5 bya, first bacteria 3.2 bya, algae (product?)3.2 bya, algae (product?) plantsplants
– photosynthesis, by-product is oxygenphotosynthesis, by-product is oxygen worms and jelly fishworms and jelly fish 500 million years ago, Cambrian (life) 500 million years ago, Cambrian (life)
explosion: marine fauna; modern phyla: explosion: marine fauna; modern phyla: sponges, mollusks (clams and snails), sponges, mollusks (clams and snails), echinoderms (sea urchins and stars), echinoderms (sea urchins and stars), anthropoda -trilobites(crabs, lobsters)anthropoda -trilobites(crabs, lobsters)
History of History of the Earththe Earth
Fossil Worm, Cambrian
Sponge
Trilobite
Earth as an Earth as an evolving systemevolving system
Creation and early EarthCreation and early Earth Earth’s chemically and physically Earth’s chemically and physically
distinct layersdistinct layers Atmosphere (air)Atmosphere (air) Hydrosphere (water)Hydrosphere (water) Biosphere (plants and animals)Biosphere (plants and animals)
SummarySummary
The Nebular HypothesisThe Nebular Hypothesis Earth’s heat sourcesEarth’s heat sources
– Radioactive decayRadioactive decay– Initial heat produced by collision of Initial heat produced by collision of
other objectsother objects Moon, water and gas formationMoon, water and gas formation Earth’s layers, differences and Earth’s layers, differences and
locationslocations Importance of gravitational pullImportance of gravitational pull
Think Quest
top related