Question

The Los Angeles area experiences many earthquakes. In 1994, the Northridge earthquake measured 6.7 on the Richter scale. In 2014, Los Angeles experienced an earthquake that measured 5.1 on the Richter scale. Compare the intensities of the two earthquakes. Use a logarithmic model to solve. Round to the nearest whole number.

Answer 1

The intensity of the 1994 earthquake was about 40 times the intensity of the 2014 earthquake.

Explanation:

1994 earthquake:

6.7I=logI=106.7

2014 earthquake:

5.1I=logI=105.1

Form a ratio of the intensities.

intensity for 1994intensity for 2014

Substitute in the values and divide by subtracting the exponents to find

106.7105.1101.6≈40.

The intensity of the 1994 Northridge earthquake in the Los Angeles area was about 40 times the intensity of the 2014 earthquake.