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Earthquakes & Faults
IV. How do seismographswork
•I. What is an earthquake•II. Types of faulting•II. Stick slip behavior•III. Types of seismic waves
10_01.jpgEarthquakes - literally - shaking ground
Cause - bending and then breaking rock
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Orientating yourself
90° (East)
180° (South)
270° (West)
0° (North)360° (North)
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This animation shows the differences between the three types of faults and illustrates how they are formed. View 1 shows a normal fault, View 2 shows a reverse fault, and View 3 shows a strike-slip fault.
PC version Mac version
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Seismologists use two basic configurations of seismographs, one for measuring horizontal ground motion, like the one shown in this animation, and the other for measuring vertical ground motion. Both work on the principle of inertia as described by Newton's law, which states that an object at rest tends to remain at rest unless acted on by an outside force. Thus, during an earthquake, vibrations cause the frame of the seismograph to move. The pendulum apparatus remains fixed as the paper cylinder moves back and forth beneath it.
PC version Mac version
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