An earthquake near the Philippines measured 51.1

on the Richter scale. Use the formula R=log(A/A0)
to determine approximately how many times stronger the wave amplitude A of the earthquake was than A0
.

1 answer

The Richter scale formula is expressed as:

\[ R = \log\left(\frac{A}{A_0}\right) \]

where:

  • \( R \) is the magnitude of the earthquake on the Richter scale,
  • \( A \) is the amplitude of the earthquake wave,
  • \( A_0 \) is a reference amplitude.

Given that the earthquake measured \( R = 51.1 \), we can rearrange the formula to solve for the ratio \(\frac{A}{A_0}\):

\[ R = \log\left(\frac{A}{A_0}\right) \implies \frac{A}{A_0} = 10^R \]

Now, substituting \( R = 51.1 \):

\[ \frac{A}{A_0} = 10^{51.1} \]

Now we calculate \( 10^{51.1} \):

\[ 10^{51.1} \approx 1.2589 \times 10^{51} \]

This means the amplitude \( A \) of the earthquake wave was approximately \( 1.2589 \times 10^{51} \) times stronger than the reference amplitude \( A_0 \).

So, the wave amplitude of the earthquake was approximately \( 1.26 \times 10^{51} \) times stronger than the reference amplitude.