Transcript Earths origin and structure.

Unit 3: Plate Tectonics Vocab
 Inner core
 Mantle
 Outer core
 Crust
 Protoplanet
 Protoplanet
hypothesis
 Asthenosphere
 Collision boundary
 Convergent boundary
 Diverging boundary
 Subduction
 Fault
 Craton
 Lithosphere
 Plate tectonics
 Spreading centers
 Mohorivic
Discontinuity “Moho”
Earth’s origin and structure.
Origin
Hypothesis
The origin of the solar system
has to consider the following
six facts.
1. All planets move around the
sun in the same direction.
2. The paths, or obits of the
planets around the sun are
elliptical.
3. Most of the orbits are in nearly
the same flat surface. (Plane)
Origin
Hypothesis
4. The sun turns on its axis in
almost the same plane as the
planets and in the same
direction that the planets
revolve.
5. Most of the planets rotate in the
same direction as the sun.
6. Seven of the nine planets have
moons. Most of the moons
revolve around the planets in
the same direction that the
planets revolve around the sun.
Protoplanet hypothesis
Protoplanet
Hypothesis
The protoplanet hypothesis suggests
that 5 billion years ago a great ball of
gas and dust rotated slowly in space. It
ranged at least 10 billion KM in
diameter.
As time passed it shrank under the pull
of its own gravity. Most of the cloud’s
material gathered around its own
center.
Its shrinking made it rotate faster. The
compression of its material made its
interior so hot that a powerful reaction,
hydrogen fusion, began and the core of
the cloud blazed into a newborn sun.
Origin of the oceans
Origin of the
oceans
When the earth was created it had
neither atmosphere nor oceans.
There were three sources of heat in
the protoplanet Earth. (compression,
radioactive materials, and meteor
showers)
The heat built up and volcanic
eruptions began. The eruptions
produced volcanic gases. The steam
in these gases condensed upon
reaching the surface to form the
earth’s oceans.
Origin of the
atmosphere
The atmosphere that surrounds
Earth today includes about 78% free
nitrogen and 21% free oxygen.
Free means gases are not combined
with any other elements.
The remaining other percent is made
up of argon, carbon dioxide, and
helium.
Free oxygen came from the
breakup of water molecules by
sunlight into the upper
atmosphere. Green plants added
more oxygen to the atmosphere by
photosynthesis.
Structure of the Solid Earth
Structure of the
Solid Earth
?
Crust:
10Km
Thick at
ocean
basin,
65Km at
mountain
top
Outer
Core:
2250K
m thick
Mantle:
2900KM
thick
Inner
Core:
1200K
m thick
What Causes the layers??? A. Density Differences,
B. Temperature differences. C. Materials
1. Crust: solid rock, includes dry and wet land.
2. Mantle: hot & solid rock
a. Lithosphere: Upper, rigid part of the mantle
1.) Moho: boundary between the crust &
mantle
b. Asthenosphere: upper most portion of mantle,
semi liquid layer
3. Core: made up of mostly metals, very hot!
a. outer core: liquid metal
b. inner core: solid, dense metal
Seismic waves
• Waves travel at
different speeds
through liquids & solids.
(Also different types of
minerals)
• http://science.discovery
.com/tv-shows/greatestdiscoveries/videos/100greatest-discoveriesthe-core-of-theearth.htm
Meteorite
• Show similar
metals to what
we believe the
core is made
of!
#14: Journey to the Center of
the Earth Textbook Time
Use the red textbook to answer the following
questions:
Pg. 130: “Analyzing Data” 1-4
Pg. 131 #’s 1 & 2
Pg. 135 #’s 1-3