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Unit 3 Dynamic Earth
At the end of this unit you will be able to
Recall that the internal heat of the earth comes from radioactive decay of materials and also residual heat from formation
State that differences in density within the earth cause the tectonic plates to move
Infer properties of the earths interior based on seismic data Recall the theory of plate tectonics, and the evidence to support it. Know the three types of plate boundaries and their properties Realize that the motion of plates causes: earthquakes, tsunamis, and
volcanoes Know the three types of seismic waves and their properties Analyze seismic waves to determine, origin time, travel time, lag time,
and distance to epicenter Read and interpret graphs and charts in the reference tables to obtain
information about plate boundaries and earthquakes
Laboratory activities for this unit
Continental drift Crustal Boundaries Finding Epicenters Location of an Epicenter Location of an Epicenter #2 Ring of fire
In your table of contents please add the followingUnit 3 Plate tectonics/Dynamic Earth
37-38 Vocabulary
39 Layers of the earth
40 Vocabulary
41-42 Theory of Plate tectonics
43 Sea Floor spreading
44 Convergent boundaries
45 Divergent boundaries- foldable
46 Transform boundaries- foldable
In your table of contents please add the followingUnit 3 Plate tectonics/Dynamic Earth
47
Now turn to page 37 and number up to page 49
On page 37 at the top please write:
Unit 4: Earth Interior vocabulary
You will be writing out 9 vocabulary words, you may not need 2 pages, but I gave you extra room in case you did.
VOCABULARY1. Crust: outermost portion of earth’s solid
lithosphere
2. Continental crust: crust that makes up the continents, granitic and less dense
3. Oceanic crust: crust under the ocean, basaltic and more dense
4. Lithosphere: whole crust together and the upper mantle
5. Moho: interface between crust and mantle
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VOCABULARY6. Asthenosphere: plastic upper portion of the earth’s mantle that the plates move on
7. Mantle: layer between the crust and outer core
8. Outer core: zone between mantle and inner core, thought to be liquid because no S waves travel through it
9. Inner core: solid, thought to be iron and nickel based on meteorites and earth’s magnetism
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I. Layers of the earth Page 10, ESRT
I. Layers of the earth
A. Crust (2 Types) Solid 1. Continental- low density,
2.7 g/cm3 , granitic
2. Oceanic- high density
3.0 g/cm3 , basaltic
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I. Layers of the earth
B. Mantle – Solid, 3.4-5.6 g/cm3
1. What the plates move on
2. Plastic like
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I. Layers of the earth
C. Outer Core – Liquid, 9.9-12.2 g/cm3
D. Inner Core – Solid, 12.8-13.1 g/cm3
1. Highest density layer
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Practice questions
• What is the pressure at the inner core and outer core boundary?
• What is the temperature at the outer core and stiffer mantle boundary?
• What is the depth of the boundary between the Asthenosphere and Stiffer mantle?
• What is the thickness of the stiffer mantle• What is the density of the oceanic crust?
VOCABULARY• Tectonic plates: section of lithosphere that
moves, aka plates
• Convergent plate boundary: boundary between two colliding plates
• Divergent plate boundary: boundary between two plates that are moving apart, new crust is created
• Transform plate boundary: boundary where two plates slide past each other
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VOCABULARY• Mid-Ocean ridge: mountain range at the
bottom of the ocean where two plates are diverging and creating new crust
• Ocean trench: deep valley produced when two convergent plates collide in an ocean
• Subduction: one of the plates at a convergent boundary sinks under the less dense plate
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II. Theory of Plate Tectonics
A. Continental Drift
1. Proposed by Alfred Wegner
2. Continents look like they fit together like a puzzle
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II. Theory of Plate Tectonics
B. Evidence of Drift (Foldable)
1. Rocks match from
continent to continent
2. Mountain chains match
3. Fossils match
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II. Theory of Plate Tectonics
C. Sea Floor Spreading
1. Oceans are getting bigger (Atlantic
Ocean)
2. caused by convection in the
mantle.
3. Evidence a. Rocks are younger at the ridges
and older as you travel away
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Pangea: Hypothetical landmass that existed 200 million years ago, where all the continents were joined.
II. Theory of Plate TectonicsD. Plate motion visualizations
1. Convergent Boundariesa. Collision: destruction of crustb. Types
1. Oceanic- Oceanic, Trench forms2. Continental- Continental, Mountains form3. Oceanic- Continental, denser plate sinks, Mountains chains along the coast and a trench forms
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II. Theory of Plate Tectonics
D. Plate motion
2.Divergent Boundaries (foldable)
a. Plates moving apart
b. New Crust is being made
c. Examples of locations: Mid
Atlantic Ridge, East Indian Ridge
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II. Theory of Plate Tectonics
D. Plate motion
3.Transform Boundaries (foldable)
a. Plates are sliding past each other
b. Shallow earthquakes
c. Example: San Andreas Fault,
CA
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The Andes Mountains
run along the west Coast of
South America
Earthquake VOCABULARY• Earthquake: rapid and natural shaking of the
earth caused by movement of the tectonic plates
• P-wave: Primary, first to arrive, fastest, travel parallel to movement direction
• S-Wave: secondary, second to arrive, travel perpendicular to wave direction
• Epicenter: place on the Earth’s surface directly above where the earthquake originated
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VOCABULARY• Focus: place where the earthquake
originated, underground
• Volcano: a mound of extrusive igneous rock that erupts
• Tsunami: large wave created when an earthquake occurs underwater
• Hotspot: a weak spot in the earths crust where magma comes up through the crust, typically in the middle of a plate
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III. Earthquakes
1. Shaking or trembling of the ground caused by motion of the plates
A. Types of earthquake Waves Foldable….
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III. Earthquakes
A. Types of Seismic waves
1.Primarya. Fastestb. Travels through, S, L, Gc. aka : Compressional
waves d. Travel parallel to vibration
III. Earthquakes
A. Types of Seismic waves 2. Secondary
a. slow wavesb. Solids ONLYc. aka” Shear waves”d. Travel perpendicular to
vibration
III. Earthquakes
A. Types of Seismic waves
3. Surface Wavesa. L- wavesb. cause all the damage
associated with the earthquakes
III. EarthquakesHow do I….? (foldables)…..Find lag time
1. Lag time is the difference between the arrivals of the S and P waves.
2. S arrival – P arrival = Lag time
3. On page 11 ESRT, it is the space between the 2 lines
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III. EarthquakesHow do I….? (foldables)….Find The travel time of the waves
1. What wave are you solving for? P or S?
2. Using pg 11 ESRT3. Knowing the distance to the
epicenter, go up to the wave you are solving for.
4. Read over to the Y axis for the time.
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III. EarthquakesHow do I….? (foldables)Find the distance to the epicenter?
1. Calculate the lag time
2. Using pg 11 ESRT, take a piece of scrap paper and place it along the Y axis, mark the zero and the lag time you calculated.
3. Slide the scrap up the graph until the 2 marks you made touch the P and S waves. (slide and match)
4. Read down to the x axis for the distance.
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III. EarthquakesHow do I….? (foldables)Find the time when the earthquake happened (origin time)?
1. Knowing the P arrival time from the seismograph.
2. subtract the Travel time for the P wave for the distance calculated for that location.
3. Origin time= P arrival – P travel
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