Seismographs: Recording Vibrations

The image to the right is a seismograph. Based on the image how do you think a seismograph machine works to detect earthquakes?

An instrument used to measure ground movement, used mainly to monitor volcanoes and record seismic waves from earthquakes.

• The recorded measurements of vibrations.  Used in determining difference in arrival time of P and S waves of an earthquake.

EQ's come from all different directions. Can a seismograph detect what direction an EQ is coming from?

• A seismologist collected this seismogram data from an EQ.

• Looking at this data try and determine what direction the EQ came from. (North, South, East West)

• A seismograph and seismogram will not record the direction of an EQ

• The data only collects the vibrations

• Can a seismograph tell how far an EQ may be from the station?

  
  

• A seismologist collected these three seismograms from an EQ. Each station was located at a different position from the EQ.

• Looking at the data can you tell which seismograph station the EQ was closest to?

• The closer to the seismograph the higher the siesmic waves

• The farther the seismograph the shorter the siesmic waves

• Seismographs can help to determine the distance of an EQ.

Can a seismograph help show the magnitude of the EQ?

• A seismologist collected information from two different size earthquakes

• Looking at the two seismograms can you tell which EQ was more powerful?

• The stronger the force of an EQ the higher the seismic waves

• The weaker the force of an EQ the lower the seismic waves