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 can’t be sure when and where stress will be released along a fault
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