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Dynamics of the Earth
Do Now:You are a geology detective, you are taking a hike in the
Appellation Mountains upstate NY… you come across marine fossil in the bed rock and ask your self “How could Marine fossil be found so high in the bedrock… how did they get
here? Give an explanation in your notebook.
I. Evidence of Crustal Motions:
A. ________________ wears down the earth’s crust.____________ _______________ creates new mountains.
Weathering & Erosion
( Uplift )Plate tectonics
B. Sedimentary beds are
deposited as_______________
__(_____ _)
Horizontal Layers
Strata
THIS SEDIMENTARY STRATA SHOWS NO EVIDENCE OF UPLIFT OR CRUSTAL MOTION LAW OF
ORIGINAL HORIZONTALITY
C. Evidence of motions within
the Earth’s crust is indicated by:1._____________2._____________3._____________
TiltingFoldingFaulting
TILTING
FOLDING
FAULTING: OFF SET LAYERS
FAULTING
D. ______________provide direct
evidence of crustal movement.
Earthquakes
World Distribution
U.S . Distribution
_______ ______ and________ _______
are 2 changes thatcan be observed after
an earthquake.
Fault lines Uplifted land (displaced strata)
EARTHQUAKE DAMAGE
E. ______ ________are used in mapping surveys and indicate exact positions and
elevations.
Bench marks
Changes in ________________
of benchmarks are evidence that the
land is either ___________
or____________risingsinking
elevation
F.Displaced marine fossils found in mountains have 2
interpretations:
1. ____________________________________________________________
2. _____________________________________________________________
Higher sea levels covered mountains
Rocks were upliftedfrom a previous ocean bottom
G. _____________is the rising of the crust_____________
is the sinking of the crust
Uplift
Subsidence
II: EARTHQUAKES
1. The movement of ____________ inside
_______________
2. _______________ is the movement of rock along a surface where the rocks are broken.
A. 2 processes that cause earthquakes:
magma
volcanoes
faulting
B. ________ movement of the crust over long periods of time builds ___________
within the rocks.
Slow
stress
Increased pressure causes the _______ _______
to break creating a ________.
Rock strata
fault
When faulting occurs energy radiates through the earth as ________ ________ that cause the ground to_______________
Seismic waves
vibrate
III.Measuring the Earthquakes:
A. There are 2 scales to measure earthquakes:
1. ________________
2. ________________
Mercalli
Richter
B. _______________ scale is based upon the observations of people and damage caused. It
measures ___________ of the earthquake from____ to ____
Mercalli
intensity
1 12
Mercalli Scale – Intensity scale
I
II
III
IV
V
VI
C._______________
uses the seismograph to determine the ________________
Magnitude is the total______ released by the earthquake.
Richter Scale
magnitude
energy
Its numerical scale is ____ to ____.
Each of the numerical steps represent ____ increase.
1 10
31X
Richter Scale – Magnitude scale
Do Now:
Read the Mercalli Intensity Scale and
the highlighted section of the script.
Let’s Use The Mercalli IntensityScale to Create
AnIsoseismal Map To Locate the
Epicenter of An Earth Quake
VII
V
V
VI
VIII
VI
VIIIVII
VI
VIII
IV
V
VII
IV
VI
IV
VII
VI
V
V
IV
V. Parts of the Earthquake:
A. The place underground where the break or fault occurs is the _______ of the quake.
focus
Do Now:
Slinky Demo Time!!! Read over the Seismic Wave
chart
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Primary (p-wave
Secondary(s-waves)
Surface
Also called… (compressional, shear)
Causes the most damage…(Check one)
Relative Speed(Slowest, Fastest or Intermediate)
Describe the Wave Motion compared to the direction that the wave is traveling.
Bonus: In what layers of the earth can they travel?
The __________ is the location along the surface of the earth just above the focus where the earthquake is felt most strongly.
epicenter
A. The 2 most important energy waves are:
P-wave or Primaryand
S-wave or Secondary
P-wave
Primary Wave
S-wave
Secondary wave
B. Characteristics of Primary Waves (P)
waves: _______________________ _______________________
_______________________ _______________________
Faster than S wavesRecorded first
travels through both solids and fluids
C. Characteristics of Secondary Waves (S)
waves: _______________________ _______________________
_______________________
_______________________
Slower than P wavesRecorded after P-wave
Can not travel
through fluids
TYPES OF EARTHQUAKE WAVES
D. Both S and P
waves travel faster through ___________
material.denser
Do Now:
Take out Chart from Slinky Demo. Finish it.
VI. Finding the Epicenter:
A. The seismograph records the ________________ and
________________________________________
magnitude
Records arrival time of seismic waves
Use reference table page 11
Seismograph
B. The steps for calculating your distance from the
epicenter:
1. ________________________2. ________________________
3. ________________________
4. ________________________
Subtract arrival time of P from arrival time of S
Mark the interval on Y-axis
Slide marks to match P & S curve
Follow down to x-axisand read distance
01:10:00 01:20:0001:18:00 01:24:00
Step 1 Subtract the arrival time
of the P wave from the
arrival time of the S wave
01:24:00 - 01:18:00 00:06:00Lag time= 6 minutes !!!
Step 2
Mark the interval on the Y-axis
Step 3Slide the marks to
match the P and S Curves.Make sure the
paper is straight!
Step 4Follow down to the X-axis
and read distance
Practice questions:
1. The arrival of the P-wave is 12:03:00.
The arrival of an S-wave is 12:07:00 the difference is:
How far is this earthquake from the seismic station? 4 minutes
2600 Km
Practice questions:2. The arrival time of the
P-wave is 2:05:00The arrival of the S-wave is 2:08:00
the difference is:How far is this earthquake from the seismic station?
3 minutes
1800 Km
Practice questions:
3. If the difference in arrival time between P and S waves is 2 minutes 35 secondswhat is the distance from the earthquake to the
Seismograph stations?1500 Km
Practice questions:
4. How long does it take for a P-wave to travel from the focus of an earthquake to a seismograph station 2,000 km. away?
4 minutes
Practice questions:5. What is the difference in
arrival time between P and S waves for an earthquake
that is 5,000 kilometer away from a seismograph station?
6 mins 40 secs
VII. THE ORIGIN TIME OF AN EARTHQUAKE:
A. Earthquake waves detected at _______ times by observers are at _______ distances from the epicenter.
later
greater
B. To find the origin time seismologists need to
know:1. _____________________
2. _____________________
Arrival time of P-wave
Travel time of P-wave(how long it took)
Example:
A seismograph recording station located 5,700 km. from an epicenter.
It receives a P-wave at 2:45pmAt what time did the earthquake actually occur at the epicenter?
First:use the distance to find outthe travel time.Then: subtract the travel time from the arrival time.
The answer is:
9 min.
2:36
Do Now: Plot the following
City Distance to Epicenter
Denver 1.50 x 103 Km
Tampa 3.80 x 103 Km
San Diego 0.65 x 103 Km
Do Now: Plot the following
City Distance to Epicenter
Wink 1.8 x 103 Km
New York 1.1 x 103 Km
Seattle 3.0 x 103 Km
SF = San Francisco 300 km
LV = Las Vegas 390 km
LA = Los Angeles 189 km
Seismic Stations
TRIANGULATION TO FIND THE EPICENTER
SF
LVLA
300 km
Do Now:Focused Free Write:
How could you use seismic (P&S) waves to determine if an egg is
raw, soft-boiled or hard-boiled without breaking the egg? Explain in 3-4
sentences.
VIII. THE LAYERS OF THE EARTH:
A. The crusts thickness______ It is _________________ under the oceans and
_________ under continents.
varies
thinner
thicker
Continental crust is mostly_______________, ____________density & __________________
The ocean basins are mostly ________ and ______ or ___________
granitic
dark densebasaltic
lowlight
B. Inferred characteristics of Earth’s
Interior:1. Studying the _____________
of _____________ ________ allows us to make inferences about the structure and composition of the Earth’s interior.
transmission
EarthQuake Waves
S-waves can not pass through liquid
P-waves are bent as they passthrough the different layers
Based on the density of the layer
2. The _____________ of a seismic wave changes with the __________ of the material it travels through.
Waves are also ___________ (bent) as they travel through different densities
velocity
density
refracted
We know that P-waves can be transmitted through
________ _______ & ______
S-Waves can be transmitted through ONLY
________________
solid liquid gas
solid
3. Earth Quake Shadow Zones:When an earthquake occurs both
____________ are received from most of the earth.
Opposite sides of the earth where the epicenter is, receives
____ but NO _______ because S-waves can not penetrate the _______ outer core.
S and P waves
SP
liquid
____________ occurs at the ___________ (boundaries)
refraction interfaces
Let’s Draw This Diagram in our Notebook:
p-wave arrival at 21:58:30
s-wave arrival at 22:02:45
surfacewaves
Summaryp-wave arrival at 21:58:30s-wave arrival at 22:02:45Difference in arrival times — 4
min. 15 sec.Travel Time Curves Distance =
2700 kmActual Distance between
Binghamton, NY and Port-Au-Prince, Haiti = 2647 km
VolcanoesA Volcano is both the opening in the Earth’s crust through which molten rock flows, and the landform that develops around it.
Mt. Etna
Where Volcanoes Form
1. At Subduction Boundaries – Subducted plate material melts to form new magma
Hot magma is less dense than surrounding rock, so it rises.
Magma reaches the surface to form volcanoes
Augustine, Alaska
Where Volcanoes Form
2. At Divergent BoundariesMagma forms at mid-ocean ridges.
Iceland formed as the result of volcanoes along the Mid-Atlantic Ridge.
Where Volcanoes Form
3. Hot Spots – Caused by plumes of hot material from deep within the mantle.
Hawaiian Islands were formed in this way.
As plate moves over hot spot, new islands form.
Mauna Loa
Kilauea
Stromboli
Stromboli
Paricutin, Mexico
Nevada Del Ruiz, Colombia
Pacaya, Guatemala
Mount Vesuvius
Pompeii
Crater Lake
