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An overview of the four primary sources of energy that fuel earth's processes: impact of extraterrestrial bodies, gravity, earth's internal heat, and the sun. It covers the role of each source in shaping the planet, from the early stages of earth's formation to the present day.
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Current Events!
Tropical Storm
GUSTAV headed
toward gulf coast
Hurricane windspeed
is 74 mph
Quake shakes Irkutsk and briefly halts Siberia rail service
The quake earlier in the day halted passenger and cargo traffic
along the only land link spanning the country.
Russian Railways had halted trains after the quake struck the
Irkutsk region near Lake Baikal.
http://www.iht.com/articles/2008/08/27/asia/siberia.php
are most deadly, and where.
costly in terms of economic loss.
and return period.
increased population growth rates since human beings
first evolved.
tornado/thunderstorm
wildfire
landslide eruption
tsunami
impact
hurricane
earthquake
The physics: follow the energy
The physics: follow the energy
Natural disasters result from rapid release of
Natural disasters result from rapid release of
concentrated energy.
concentrated energy.
Where does the energy come from and where
Where does the energy come from and where
does it go?
does it go?
units of energy: joules [J = kg·munits of energy: joules [J = kg·m
22
/s/s
22
] (or calories)] (or calories)
The origin of our solar system involvesThe origin of our solar system involves
another form of energy: Nuclear fusion.another form of energy: Nuclear fusion.
Nuclear fusion of hydrogen into heavier
Nuclear fusion of hydrogen into heavier
elements inside star(s).
elements inside star(s).
Impact origin of Moon Impact origin of Moon
http://63.114.151.211/release/
http://63.114.151.211/release/
/anim24n.mov/anim24n.mov
From the Southwest ResearchFrom the Southwest Research
InstituteInstitute
Earth differentiates into crust, mantle, and
Earth differentiates into crust, mantle, and
core
core
Differentiated
Differentiated into layers of
into layers of
increasing density increasing density
Center: Iron-richCenter: Iron-rich corecore ~3500 km~3500 km
in radius
in radius
Inner core is
Inner core is solid
solid
Outer core isOuter core is liquidliquid →→EarthEarth’’ss
magnetic fieldmagnetic field
Surrounding core is
Surrounding core is mantle
mantle ,
~3000 km thick ~3000 km thick
StonyStony in compositionin composition
Low-density elements have been
Low-density elements have been
‘ ‘sweatedsweated’’ out of the mantle toout of the mantle to
form the form the crust, atmosphere andcrust, atmosphere and
oceans
oceans
Earth is a series of
Earth is a series of
density-stratified
density-stratified
layers layers
Atmosphere
Atmosphere
least
least
dense dense
OceansOceans – – densitiesdensities
~1.03 g/cm
~1.03 g/cm
33
Continents
Continents (crust)
(crust)
densities ~2.7 g/cm densities ~2.7 g/cm
3
3
MantleMantle – – densities ~5.7densities ~5.
to 3.3 g/cm
to 3.3 g/cm
33
CoreCore – – densities up todensities up to
16 g/cm 16 g/cm
3
3
LakeLake Mead,Mead, HooverHoover DamDam
Scandinavia rising (~200 m so far, 200 m more likely)
Scandinavia rising (~200 m so far, 200 m more likely)
Ground ruptures and earthquakes are presentGround ruptures and earthquakes are present
Viking ship in Stockholm harbor raised above sea levelViking ship in Stockholm harbor raised above sea level
Heat
Heat from both of these early sources still flows
from both of these early sources still flows
to surface today, as it conducts very slowlyto surface today, as it conducts very slowly
through rock
through rock
a. impact energy: a huge number of smaller bodies
hit Earth soon after its formation, converting
energy of motion to heat
b. gravitational energy: as Earth pulled to
smaller/denser mass, things heated up
Isotopes: different forms of the same element withIsotopes: different forms of the same element with
different numbers of neutrons (
different numbers of neutrons ( n
n )
)
Radioactive isotopes are unstable and release energy byRadioactive isotopes are unstable and release energy by
decaying to stable isotopes
decaying to stable isotopes
Some important types of nuclear decay:Some important types of nuclear decay:
Alpha Alpha decay,decay, Beta Beta decay,decay, Electron capture Electron capture
α -decay
Radioactive atoms decay and releaseRadioactive atoms decay and release heatheat
U,U, ThTh, and K are the most important today, and K are the most important today
In early Earth, many more radioactive elements were aroundIn early Earth, many more radioactive elements were around——so itso it
was (a lot)was (a lot) hotterhotter!!
half-lifehalf-life :: length of time for half the radioactive parentlength of time for half the radioactive parent
atoms to decay to daughter atoms atoms to decay to daughter atoms
Sum of internal energy from impacts, gravity and
Sum of internal energy from impacts, gravity and
radioactive elements is big radioactive elements is big
Internal Temperature has been declining since early Earth
Internal Temperature has been declining since early Earth
maximum, but still causes plate tectonics, maximum, but still causes plate tectonics, EQsEQs and volcanicand volcanic
eruptions eruptions
Internal heat flow on Earth is dwarfed by 4,000 times
Internal heat flow on Earth is dwarfed by 4,000 times
greater heat flow to Earth from greater heat flow to Earth from SunSun
Internal heat flow on Earth is dwarfed by 4,000 times
Internal heat flow on Earth is dwarfed by 4,000 times
greater heat flow to Earth from greater heat flow to Earth from SunSun
Solar energy drives
Solar energy drives
hydrosphere, atmosphere,hydrosphere, atmosphere,
& biosphere
& biosphere
97.1%97.1% of Earthof Earth’’s water is in oceanss water is in oceans
Of remaining 2.9%:Of remaining 2.9%:
68%68% in glaciersin glaciers
21%
21% underground
underground
10%10% in atmospherein atmosphere
1%1% in rivers, lakes, inland seas and soil moisturein rivers, lakes, inland seas and soil moisture
Water in atmosphere/ocean holds, transports and releases solarWater in atmosphere/ocean holds, transports and releases solar
energy...energy...
Hydrologic CycleHydrologic Cycle
...sometimes violently...
...sometimes violently...
abundant in early Earth history, rare nowabundant in early Earth history, rare now
Mass of Earth pulls objects (glaciers, hillsides)
Mass of Earth pulls objects (glaciers, hillsides)
downhilldownhill
As Earth cools, heat flows from interior to surface
As Earth cools, heat flows from interior to surface
Volcanic eruptions, earthquakesVolcanic eruptions, earthquakes
Plate tectonics; formation of continents, atmospherePlate tectonics; formation of continents, atmosphere
and oceans
and oceans
Evaporation of water into atmosphere producesEvaporation of water into atmosphere produces
weather
weather
Hailstorms, lightning, tornadoes and hurricanes
Hailstorms, lightning, tornadoes and hurricanes
It drives plate tectonics!
It drives plate tectonics!
