Question

an older type of seismometer in which a suspended, weighted pen wrote on a drum that moved with the ground is known as:
a seismographs
b sonargraphs
c richter scales
d none of the above

Explanation:

• Seismographs are older seismometers that use a suspended weighted pen to record ground movement on a moving drum.
• Sonargraphs are used for sound/sonar data, not seismic activity.
• Richter scales measure earthquake magnitude, they are not recording seismometers.

Answer:

a. Seismographs