What is the ML calculated for a local earthquake with an S-P arrival difference of 2.0 sec and maximum S-wave amplitude of 1 mm?

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Quizplus · Accepted Answer

The Richter magnitude scale, or local magnitude (ML), is calculated using the formula ML = log10(A) - log10(A0(Δ)), where A is the maximum amplitude of the S-waves recorded by a seismograph (in mm), and A0 is a function of the distance to the epicenter (Δ). For an S-P arrival difference of 2.0 seconds, which typically corresponds to a relatively short distance from the epicenter, and a maximum S-wave amplitude of 1 mm, the calculated magnitude would be approximately 1.5, based on standard empirical relationships used in seismology.

What Is the ML Calculated for a Local Earthquake with an S-P