An Earthquake in the Japan in 2011 Was About 10 $R = \log \frac { I } { I _ { 0 } }$

Multiple Choice

An earthquake in the Japan in 2011 was about 10 9 times as intense as the reference intensity. Find the Richter number for that earthquake. NOTE: Seismologists use the Richter scale to measure and report the magnitude of earthquakes. The equation $R = \log \frac { I } { I _ { 0 } }$ compares the intensity I of an earthquake to a minimum or reference intensity I 0.

A) 10⁹
B) 10
C) 9
D) none of these