Monitoring Earthquakes

1
Monitoring Earthquakes

• Chapter 6 Section 3

2
Seismograph

• An instrument that measures the vibrations from
  an earthquake
• A seismogram is the recording of the vibrations

3
Instruments that monitor faults

• Tiltmeter two bulbs that are filled with a
  liquid and are connected by a hollow stem

4
Instruments that monitor faults

• Creep Meter A wire stretched across a fault and
  attached to a post on one side and a weight and
  pulley on the other.

5
Instruments that monitor faults

• Laser Ranging Device times how long a laser
  beam travels to and back from a reflector. A
  change in time indicates a change in distance.

6
Instruments that monitor faults

• GPS Satellites satellites are used to measure
  the movements
• of markers on opposite
• sides of a fault

7
Predicting Earthquakes

• When friction between the opposite sides of a
  fault is high, the fault locks and stress builds
  up until an earthquake occurs
• Geologists know that wherever plate movement
  stores energy in the rock along faults,
  earthquakes are likely.

8
Predicting Earthquakes

• We cannot yet predict earthquakes because we
  cant be sure when and where stress will be
  released along a fault
• Video