The Solid Earth

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The Solid Earth

• Layers and Structure
• (Intro to Geology)

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More than meets the eye
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What is the Earth like?
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Earth like an Apple
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Travel from the Outside In
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The Crust- the SKIN

• Crust- made of mostly O and Si (and others such
  as Al, Fe, Ca, Na, K and Mg)

Oceanic- under the ocean Thinner than
continental.
Continental- part of the land, under your feet
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Mantle- the FLESH

• Mantle- 1,800 miles thick, Divided into two (2)
  parts, made of rock

Upper Mantle
Lower Mantle
L
A
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Upper Mantle

• Divided into (2) two parts- think L.A.

Lithosphere- rigid (hard, stiff) Note includes
the crust (can break!!!)
Asthenosphere- plastic like, semi-solid, flows
like silly putty, caramel
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Lower Mantle

• Semi Solid
• What does it mean?
• Compared to taffy, caramel or rubber!

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Outer Core

• Liquid metal
• Ocean of Spinning metal!
• Made up of Fe and Ni
• VERY Hot!!!!!! Hotter than the Inner Core!
• WHY?

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Inner Core- the PIT

• Solid metal
• Spinning metal!
• Mostly iron (Fe)
• Also nickel (Ni)
• Very hot!!!!!! BUT- cooler than the Outer Core!
  WHY?
• Together with the Outer Core it generates the
  Earths magnetic field!

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What does it all look like?
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The Layers
Continental Crust
Oceanic Crust under ocean
Upper Mantle
Lower Mantle
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Do you Know it?
This does not include the core!!!
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You got it?
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What is the Moho?

• Mohorovicic Discontinuity
• What is it?

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Apples or avocados??? What do you like?
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One last look...
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Do you know it?
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Plate TectonicsContinental Drift and Pangaea
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Continental Drift

• Puzzles and Alfred Wegener (1912)
• Observations and evidence continetal margins,
  fossils, rock age, glaciers and mountain chains.
• Moving land
• Hypothesis the continents have once been joined
  together in one big land massgt
• Pangaea

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Pangaea
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How did it move? When?
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New Conclusive Evidence

• Seafloor spreading- discovered in the 1947
• Moving seafloor creates mid-ocean ridges
• New rock from the mantle replaces broken crust

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Under the sea

• Mid-Atlantic Ridge
• Mid-ocean Ridges

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The Big Picture Plate Tectonics

• The theory of plate tectonics describes how and
  why the continents move.
• Plate rigid slab/piece of rock
• Tektonikos greek word meaning construction or
  to build

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Can you make Pangaea?
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Plate Tectonics 2Plate Boundaries and Movement
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REMINDER Plate Tectonics

• The theory of plate tectonics describes how and
  why the continents move. Think Pangaea!!!!
• Plate rigid slab/piece of rock
• Tektonikos greek word meaning construction or
  to build

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How does this look like?

• The Earths crust is broken into large pieces
  called lithospheric plates. Imagine a cracked,
  hard-boiled egg.

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Plate Boundaries

• The Edges of the plates, where they touch other
  plates, are called plate boundaries

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Plate Movement vs. Boundary

• The way the plates move, determines the type of
  plate boundary meaning

Convergent
Divergent
Transform
Towards Each other
Away from each other
Slip sideways past each other
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Plate Movement

• These plates move in three different ways
• Towards eachother
• Away from eachother
• Slip sideways past eachother

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What does it look like?
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Once again
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Divergent Boundary

• Plates pulling away from one another
• What do we get? Ocean Ridges (under water) or
  Rift Valleys (on land)

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Transform Boundary

• Plates slide and grind next to each other, side
  to side
• What do we get? Faults, earthquakes!

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Convergent Boundary

• Plates push against each other
• How many kinds?
• OO, CO and CC
• What do we get?

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What happens? Why?

• The movement of these plates over millions of
  years have caused the continents to drift (move).
  Think Pangea.
• The oceans and continents sit on top of these
  plates and therefore they move when the plates
  move. Even today!
• Why? Convection currents within the Earth Layers.
  Think pot of boiling water!

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Seismic MovementEarthquakes
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What are Earthquakes? Where?

• Vibrations of the Earths crust
• Where?
• They occur mostly when rocks under stress
  suddenly shift or move along a fault
• What is a locked fault?

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Elastic Rebound Theory
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Words to know

• Seismic Waves- energy in the form of vibrations
  as the rocks move
• Aftershocks- smaller tremors, as the rocks come
  back into their original position
• Focus- where rocks first slip
• Epicenter- point on the earths surface directly
  above the focus
• Magnitude- how strong

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Whats it look like?
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Where do they happen?
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The Pacific Ring of Fire

• What?
• Where?
• What?
• Fault Zones
• Volcanoes
• Trenches

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How do we measure just kidding!
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How do we measure?

• Seismograph
• Detects and records seismic waves in three
  different ways
• What kind of waves?
• What are they called?

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Seismic Waves

• P waves- primary waves- fastest, travel through
  solid and liquid
• S waves- secondary waves, travel through solid
  only
• Surface Waves- when P and S waves reach the
  surface, they become surface waves, slowest
• Think water ripple effect

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More waves
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Waves
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What scales do we use to measure earhquakes?

• Magnitude (Richter Scale)- measures energy
  released, related to cause. 1 and up
• Intensity (Mercalli Scale)- measures amount of
  demage it causes, related to effect. I to XII and
  description

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Locating an Earthquake

• Three Stations needed
• Why?
• How?

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Locating an Earthquake
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Tsunamis

• Tsunamis- giant wave caused by an earthquake
  whose epicenter is on or under the ocean floor.

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How tsunamis work!
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What does it look like?
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Indonesia, 2004
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Banda Ache, Indonesia
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Videos, predictions and aftershocks

• Lets see actual footage
• Predictions?
• Aftershocks?