A seismic station records an earthquake that has a maximum surface wave amplitude of 50 mm and the S-wave arrives 2 seconds after the P-wave. The Richter magnitude of this earthquake is
A) 3.
B) 4.
C) 5.
D) 6.

Question

Quizplus · Accepted Answer

The Richter magnitude is calculated using the formula: M = log10(A/A0) + log10(Δt/Δt0) + C, where A is the maximum surface wave amplitude, A0 is the reference amplitude (1 μm), Δt is the time interval between the P-wave and S-wave arrivals, Δt0 is the reference time interval (1 second), and C is a constant (0.02). Plugging in the given values, we get: M = log10(50/1) + log10(2/1) + 0.02 = 3.

A Seismic Station Records an Earthquake That Has a Maximum