Question

How is the magnitude of an earthquake determined by a seismograph?

Answer 1

The magnitude of an earthquake is detemined by a seismogrpah because this instument records the force, duration, and amplitude of waves in an earthquake.

Answer 2

The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs.

Step-by-step explanation:

The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are included in the magnitude formula to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquakes.