Download the COMPLETED version of "Dynamic Earth Guided Notes"

Name: ______________________________________________________ Date: _______________________ Period: _______________
Guided Notes – Dynamic Earth
Topic(s): Earthquakes
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Earthquake
o Mr. Parr’s Earthquake Video: http://www.youtube.com/watch?v=sA6oZ4YgKCA
o Earthquake Definition: Vibrations caused by the rupture and sudden movement of rocks
along a plate boundary or fault in Earth’s crust.
Fun Facts
o The largest earthquake ever recorded in the world was in Chile in 1960. It measured a 9.6
on the Richter Scale. The largest in the US was a 9.2 magnitude in Alaska in 1964.
o They can cause huge waves in the ocean called tsunamis.
o Movement of tectonic plates has formed large mountain ranges like the Himalayas and the
Andes.
o Earthquakes can happen in any kind of weather.
o Alaska is the most seismically active state and has more large earthquakes than California.
Scientific Model
o Scientific Model Definition: A “testable idea” created by the human mind that tells a story
about what happens in nature. All models have limitations — no model can possibly explain
every detail of a scientific phenomena.
Scientific Modeling
o Scientific Modeling Definition: Scientific modeling is a scientific activity that aims to
make a particular part or feature of the real world easier to understand or simulate.
Modeling Particle Motion
o Particle Motion Definition: The movements of particles of material as specific types of
waves move through a specific material.
Refraction
o Refraction Definition: The bending of seismic or energy waves when they pass through one
medium (substance) to another.
o DEMO: Coin Trick
Seismic Shock Wave
o Seismic Wave Definition: Energy that travels as vibrations on and in Earth. They move
quickly at 20 times the speed of sound.
o Scientists use seismic waves to measure how big an earthquake is. They use a device called
a seismograph to measure the size of the waves. The size of the waves is called the
magnitude.
Types of Earthquake Waves
o Primary Waves (p-waves)
o Secondary Waves (s-waves)
o Rolling Waves (r-waves)
o Lateral Waves (l-waves)
How are Earthquakes Recorded?
o Earthquakes are recorded by instruments called seismographs. The recording they make is
called a seismogram (image below).
o Seismograph Definition: An instrument that measures and records ground motion and can
be used to determine the distance seismic waves travel.
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The seismograph has a base that sets firmly in the ground, and a heavy weight that hangs
free. When an earthquake causes the ground to shake, the base of the seismograph shakes
too, but the hanging weight does not. Instead the spring or string that it is hanging from
absorbs all the movement. The difference in position between the shaking part of the
seismograph and the motionless part is what is recorded.
Seismogram Image
Primary Waves
o Primary Wave Definition: Known as a “p-wave”, is a type of seismic wave that causes
particles in the ground to move in a push-pull motion similar to a coiled spring. They travel
through any material and are the fastest.
o SLINKY DEMO
Secondary Waves
o Secondary Wave Definition: Known as a “s-wave”, is a type of seismic wave that causes
particles to move in an up-down motion. They travel only through solids and are detected
second by seismographs.
o SLINKY DEMO
Surface Waves
o Rolling Wave Definition: Known as a “r-wave”, is a type of surface seismic wave that on
the surface of the Earth moves in a rolling manner.
o Lateral Wave Definition: Known as a “l-wave”, is a type of surface seismic wave that on the
surface of the Earth moves in a side-to-side manner.
o SLINKY DEMO
Where Can Earthquakes Occur?
o Earthquakes occur in a variety of locations. Most often, earthquakes originate along plate
boundaries but can be felt practically anywhere on Earth’s surface.
o Remember trenches?
- A deep “ditch” in the ocean floor formed at subduction zones due to a (oceanocean or ocean-continental) convergent plate boundary.
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It is here where earthquakes are common due to a slab-pull motion generating a
lot of friction between plates.
Earthquake iPad Application
o “Earthquakes and Map ALERT”  iPad or iPhone Application
o Google Earthquake Tracker – GOOGLE EARTH
- http://earthquaketrack.com/recent
Notable Earthquakes
o Sumatra, 2004 (9.0-9.3 Richter)
http://www.youtube.com/watch?v=SGXx-KPFyGc
o Alaska, 1964 (9.2 Richter)
o San Francisco, 1989 (6.9 Richter)
http://www.youtube.com/watch?v=qpAPILKw3iY&list=PLF6AE2E7782BE0FDD
o Virginia, 2011 (5.8 Richter)
o Chile, 1960 (9.5 Richter)
***STRONGEST EVER RECORDED!!!! (1960 Valdivia, Chile)***
Focus vs. Epicenter
o Epicenter Definition: The location on Earth’s surface directly above an earthquake’s focus.
o Focus Definition: A single location inside the Earth where seismic waves originate and
rocks first move along a fault.
- (Hint: This is the starting point for an earthquake.)
Why do Earthquakes Occur Where They Do?
o The Earth’s uppermost layers are much like puzzle pieces. We call these puzzle pieces
tectonic plates, and the edges of the plates are called the plate boundaries.
o The plate boundaries are made up of many faults, and most of the earthquakes around the
world occur on these faults.
o Since the edges of the plates are rough, they get stuck while the rest of the plate keeps
moving. Finally, when the plate has moved far enough, the edges unstick on one of the
faults and there is an earthquake.
o Friction Definition: is the resistance of motion when one object rubs against another.
Anytime two objects rub against each other, they cause friction.
- DEMO: (RUB HANDS TOGETHER) (MATCH) (FAULT BLOCKS DEMO)
Aftershock
o Aftershock Definition: A smaller earthquake following the main shock of a large
earthquake.
Tsunamis
o Tsunami Definition: a long high sea wave caused by an earthquake, submarine landslide, or
other disturbance.
o DEMO WITH FISHTANK AND RIPPLES
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Tsunami Formation Link: http://www.youtube.com/watch?v=4Xebwzb3dDE
Japan Tsunami Aerial View: http://www.youtube.com/watch?v=w3AdFjklR50
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Remember the Focus and Epicenter? Let’s Triangulate!!!
o Triangulation Definition: A method used to determine exactly where the earthquake’s
epicenter is located. It is called triangulation because a triangle has three sides, and it
takes three seismographs (devices that detect earthquakes) to locate an earthquake.
o Triangulation Animation Web link: http://www.estium-concept.com/en/computer_graphicsgeology_epicenter.htm
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Triangulation Example
o Seismograms (diagrams from seismographs) come in handy for locating earthquakes too,
and being able to see the P wave and the S wave is important.
o You learned how P & S waves each shake the ground in different ways as they travel
through it. P waves are also faster than S waves, and this fact is what allows us to tell
where an earthquake was.
o THINK ABOUT THIS!
- To understand how this works, let’s compare P and S waves to lightning and
thunder. Light travels faster than sound, so during a thunderstorm you will first
see the lightning and then you will hear the thunder. If you are close to the
lightning, the thunder will boom right after the lightning, but if you are far away
from the lightning, you can count several seconds before you hear the thunder.
The further you are from the storm, the longer it will take between the
lightning and the thunder.
“ EARTHQUAKE POWER RANKINGS”
o There are two types of scales that measure the intensity of earthquakes.
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1. Richter Scale
2. Modified Mercalli Scale
Richter Scale
o Richter Scale Definition: A numerical scale for expressing the magnitude (strength) of an
earthquake based on seismograph readings. This scale ranges from 0 to 10, where a 10 is
the strongest reading.
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Modified Mercalli Scale
o Modified Mercalli Scale Definition: A scale of earthquake intensity based on human
observed effects. The scale ranges from I (detectable only with instruments) to XII
(causing almost total destruction). Scale is from 1-12.
- DEMO ACTIVITY: Arrange 12 different descriptions in order from least severe
to most severe using felt uniforms.
- http://elearning.niu.edu/simulations/mercalli.html
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Can Scientists Predict Earthquakes?
o No, and it is unlikely they will ever be able to predict them. Scientists have tried many
different ways of predicting earthquakes, but none have been successful. On any
particular fault, scientists know there will be another earthquake sometime in the future,
but they have no way of telling when it will happen.
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REVIEW PROBLEMS
1. A ________________ is the device that records the strength of an earthquake, whereas a _______________
actual diagram of the recordings.
a. Seismogram; Seismograph
b. Seismometer; Seismogram
c. Seismic Wave; Seismogram
d. Seismograph; Seismogram
is the
2. _________________ are best described as having a push-pull motion.
a. S-waves
b. P-waves
c. R-waves
d. L-waves
3. Which of the follow are examples of surface waves?
a. L-waves
b. S-waves
c. R-waves
d. P-waves
e. Both L & R waves
f. Both S & P waves
4. The location on Earth’s surface directly above an earthquake’s origin is defined as ____________.
a. Focus
b. Epicenter
c. The North Pole
d. Triangulation Point
5. Which of the following is the S-wave on the seismogram?
ANSWER: B
6. The Richter Scale is measured on a scale ranging from _________ and the Modified Mercalli Scale is measured on a
scale ranging from _________.
a. 1-10; 1-12
b. 1-10; I-XII
c. I-XII; 1-10
d. 1-45000; 1,000,000,000-1,000,000,001
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