Inside Earth Chapter 2.4Pages 78-81

FaultsMonitoring

• Instruments used to observe changes and measure stress and deformation of the crust.1. Creep Meters2. Laser-Ranging Devices3. Tiltmeters4. Satellites

Devices that Monitor Faults

Creep Meters• A meter with a wire stretched across a fault to

measure horizontal movement– Wire is anchored to a post– The wire on the other side of the fault has a

weight attached to it– Movement can be determined by measuring how

much the weight has moved.

Laser-Ranging Devices• Detects tiny fault movements with a laser

– The device measures the time it takes for the beam to travel to a reflector and back

– Can detect any change in distance.

Tiltmeters• Containers of water measure the tilting of the

ground– Acts like a carpenters level.

• Geologists read the scales to see how much tilting is happening along a fault.

Satellites• Satellites bounce radio waves off

the ground and the satellite records them

• Can detect small changes in elevation, may result when stress deforms the ground.

• Geologists cannot predict earthquakes.– Exactly what will happen remains uncertain.

• Stress may build up and not release an earthquake.• Or stress may be released in another part of the

fault.

• Geologists know that earthquakes are likely wherever plate movements store energy in the rock along faults.– Geologists can determine the risk by where faults

are active and other earthquakes have occurred.

Monitoring Risk in the US

Monitoring Risk in the US

Page 81 in textbook.

What to Work On• Chapter Review on pages 83-85• Define the Key Terms• Answer as many questions as you can

– Include the page you found the answer on• You may work in groups of 2

– Whispering only!– If you or your group member is not on task, BOTH

of you will be written up

• Kristen, Nick, Nic, Alyssa, Sal, Rocco, Gianna, Sam, Mikaela, Kelsie, LaMarre, Christine, Ethan, Jakiah, Cheyenne, Sierra, Mike

• Chapter Review on pages 83-85• Define the Key Terms• Answer as many questions as you can

– Include the page you found the answer on

What to Work On