K-W-LWHAT DO YOU KNOW ABOUT EARTHQUAKES?

IN YOUR NOTEBOOK: TAKE 3 MINUTES TO WRITE DOWN AS MUCH AS YOU KNOW.

Normal fault: Tension Forces

Reverse Fault: Compressional Forces

Earthquake energy

Kinetic Energy: energy of motion

Potential Energy: Stored energy in an object that can be converted into kinetic energy.

DO NOW: SILENTLY

1. Draw the fault below on your do now sheet and include the following information

• Name: _______

• The type of force: _____ (compressional or tension)

• Arrows showing direction of force movement:_____

2. How would you explain the cause of earthquakes to someone?

WHAT CAUSES EARTHQUAKES?• Tectonic plates move past each other causing stress. Stress causes the rock to deform

• Elastic deformation – rock stretches then reaches a breaking point, releasing energy.

Elasticity: The ability of a material to “rebound” into its original state after being deformed.

ELASTIC REBOUND – DEFORMED ROCK GOES BACK TO ITS ORIGINAL SHAPE

http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM

PRIMARY WAVES (P WAVES)

• A type of seismic wave that compresses and expands the ground

• Rocks move in the same direction as the wave

• The first wave to arrive at epicenter after an earthquake

SECONDARY WAVES (S WAVES)

• A type of seismic wave that moves the ground up and down or side to side (at right angles)

http://daphne.meccahosting.com/~a0000e89/insideearth2.htm

SURFACE WAVES• Cause the most damage

• Arrive after S and P waves

SURFACE WAVES

• Move along the Earth’s surface

• Produces motion in the upper crust

• Motion can be up and down

• Motion can be around

• Motion can be back and forth

• Travel more slowly than S and P waves

• More destructive

DO NOW: SIMILARITIES AND DIFFERENCES BETWEEN P AND S WAVES

P waves S waves

DO NOW:

• Solve: How much more energy is released in a magnitude 8 earthquake than a magnitude 5?

SHOW YOUR MATH!

COMPARING SEISMIC WAVES

HOW SEISMOGRAPHS WORK

http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM

the pendulum remains fixed as the ground moves beneath it

TYPICAL SEISMOGRAM

http://isu.indstate.edu/jspeer/Earth&Sky/EarthCh11.ppt

HOW DO SCIENTISTS CALCULATE HOW FAR A LOCATION IS FROM THE EPICENTER OF AN EARTHQUAKE?

Lag Time: • Scientists calculate the difference

between arrival times of the P waves and S waves

• The further away an earthquake is, the greater the time between the arrival of the P waves and the S waves

LOCATING EARTHQUAKES

http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM

LOCATING EARTHQUAKES

http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM

LOCATING EARTHQUAKES

http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM

HOW ARE EARTHQUAKES MEASURED? RICHTER SCALE

HOW ARE EARTHQUAKES MEASURED? MERCALLI INTENSITY SCALE

Click Link for Interactive Demo http://elearning.niu.edu/simulations/images/S_portfolio/Mercalli/Mercalli_Scale.swf

1/11 Do Now: Record your observations about the scene below. Using terms from this week, explain what caused the damage.

LOCATING EPICENTERS

1/15 Do Now: Record your observations and thoughts about the map below. Describe in detail what you are seeing. Does it make sense?

PRIMARY HAZARDS

AFTERSHOCKS

FOUNDATION FAILURE

SECONDARY HAZARDS

LIQUEFACTION

LANDSLIDES

FIRES

TSUNAMIS - PACIFIC REGION WARNING SYSTEM

"ONLY FOOLS, CHARLATANS, AND LIARS PREDICT EARTHQUAKES"

-CHARLES RICHTER

NEW MADRID, MISSOURI1811, 1812

PALEOSEISMOLOGY

SEISMIC GAPS