Science Science Shake, Rattle, and RollShake, Rattle, and Roll

Chapter 8Chapter 8

What Causes Earthquakes, What Causes Earthquakes, and How Can They Be and How Can They Be

Compared?Compared?

EarthquakeEarthquake is a vibration of is a vibration of Earth, caused by release of Earth, caused by release of energy that has been stored energy that has been stored

along a fault.along a fault.

Most occur along tectonic plate Most occur along tectonic plate boundariesboundaries

Think about this…Think about this…

What do you think happens when an What do you think happens when an earthquake occurs?earthquake occurs?

What kind of damage could these events What kind of damage could these events cause?cause?

Guatemala, Guatemala, 19761976

23,000 people 23,000 people killedkilled

Mexico , 1985Mexico , 1985

9,000 people 9,000 people killedkilled

Earthquakes happen on Earthquakes happen on faults.faults.

Who can remember the Who can remember the name of the fault line that name of the fault line that runs along the length of runs along the length of

California?California?

Aerial photo of the Aerial photo of the San Andreas FaultSan Andreas Fault

720 miles long720 miles long

AftershockAftershock- is a shock that occurs - is a shock that occurs after the first shock of the after the first shock of the

earthquake.earthquake.

Richter ScaleRichter Scale

Are numbers ranging from 1 to 10 that Are numbers ranging from 1 to 10 that describes the magnitude, or strength, of describes the magnitude, or strength, of an earthquake.an earthquake.

Named after American scientist Charles Named after American scientist Charles RichterRichter

Minor earthquakes are under 4Minor earthquakes are under 4

Major earthquakes are over 5Major earthquakes are over 5

Magnitude- is the amount of Magnitude- is the amount of energy released by the energy released by the

quake.quake.

FocusFocus- the point at which - the point at which an earthquake begins an earthquake begins

EpicenterEpicenter- the point on - the point on Earth’s surface directly above the Earth’s surface directly above the

focus of an earthquake focus of an earthquake

What do you call a scientist What do you call a scientist that studies earthquakes?that studies earthquakes?

SeismologistsSeismologists

Predicting EarthquakesPredicting Earthquakes

Seismologist have found that there are Seismologist have found that there are changes in the earth before earthquakes changes in the earth before earthquakes happen.happen.

So, they watch instruments that measure So, they watch instruments that measure and record these changes.and record these changes.

How do scientists measure How do scientists measure the strength of an the strength of an

earthquake, and how can earthquake, and how can they predict future they predict future

earthquakes?earthquakes?

Lesson 1 reviewLesson 1 review

1.1. Where do earthquakes occur?Where do earthquakes occur?

2.2. What is an earthquake?What is an earthquake?

3.3. What is the smaller earthquake like What is the smaller earthquake like activity the happens after the first activity the happens after the first earthquake?earthquake?

4.4. Who studies earthquakes?Who studies earthquakes?

5.5. How can you predict an earthquake?How can you predict an earthquake?

What Happens To Earth’s crust During an What Happens To Earth’s crust During an Earthquake? Earthquake?

How are Earthquakes Located and How are Earthquakes Located and Measured?Measured?

SeismographSeismograph

Seismic waves are recorded by Seismic waves are recorded by this instrument this instrument

Pendulum Pendulum seismographseismograph measures side to side measures side to side movements.movements.

Spring seismographSpring seismograph measures up and measures up and down movements.down movements.

Chinese created the first earthquake Chinese created the first earthquake detectors known as Chang Heng’s detectors known as Chang Heng’s

seismoscope in AD132.seismoscope in AD132.

TsunamisTsunamis

Is a seismic sea wave forms when Is a seismic sea wave forms when earthquakes hit the ocean floor. earthquakes hit the ocean floor.

DESTUCTIVE WALLS OF WATERDESTUCTIVE WALLS OF WATER

Causes of TsunamisCauses of Tsunamis

Earthquakes on the sea floorEarthquakes on the sea floor

Landslides on the ocean floorLandslides on the ocean floor

Volcanic eruptionsVolcanic eruptions

Tsunami FactsTsunami Facts

Can begin at 3ft and can reach a height of Can begin at 3ft and can reach a height of 46ft when it strikes land.46ft when it strikes land.

Travels at 500 mphTravels at 500 mph

Before AfterBefore After

Loss of land Loss of land

Loss of grass/treesLoss of grass/trees

Predicting TsunamisPredicting Tsunamis1946 the Tsunami Warning System was 1946 the Tsunami Warning System was

established to warn people.established to warn people. Two warning centers in the USA near Two warning centers in the USA near Anchorage, Alaska and near Honolulu, Anchorage, Alaska and near Honolulu,

Hawaii. Hawaii. Tsunami sensors that rest of the ocean Tsunami sensors that rest of the ocean

floor. These sensors are very sensitive and floor. These sensors are very sensitive and can detect a change in sea level of less than can detect a change in sea level of less than

millimeter.millimeter.

Chapter 8 ReviewChapter 8 Review

VocabularyVocabularyAftershockAftershockEarthquakeEarthquakeFaultFaultRichter ScaleRichter ScaleSeismographSeismographSeismologistSeismologistTsunami Tsunami MagnitudeMagnitudeEpicenterEpicenterfocusfocus

Short Answer Questions:Short Answer Questions:

1.1. What kind of damage could these events What kind of damage could these events cause?cause?

2.2. How do scientists measure the strength How do scientists measure the strength of an earthquake, and how can they of an earthquake, and how can they predict future earthquakespredict future earthquakes

3.3. What three things Happen to Earth’s What three things Happen to Earth’s crust during an Earthquake? crust during an Earthquake?

Test Questions:Test Questions:

1.1. What is an earthquake?What is an earthquake?

2.2. Where do earthquakes occur?Where do earthquakes occur?

3.3. What is the smaller earthquake like activity the What is the smaller earthquake like activity the happens after the first earthquake?happens after the first earthquake?

4.4. Who studies earthquakes?Who studies earthquakes?

5.5. How can you predict an earthquake?How can you predict an earthquake?

6.6. What causes a tsunami?What causes a tsunami?

7.7. What are the two kinds of seismographs and What are the two kinds of seismographs and what kind of movements does each measure?what kind of movements does each measure?

Test Question :Test Question :What is this a picture of?What is this a picture of?

Test Question:Test Question:What is this a picture of?What is this a picture of?

Bonus:Bonus:1. What is this a picture of?1. What is this a picture of?

2. What is this called?2. What is this called?3. What country did it come from?3. What country did it come from?