An Earthquake Was Recorded with a Shock Wave Which Was

Multiple Choice

An earthquake was recorded with a shock wave which was 7,943,282 times more powerful than the smallest measurable shock wave recordable by a seismograph. What is the magnitude of this earthquake on the Richter scale (rounded to the nearest tenth) ? The magnitude on the Richter scale of an earthquake of intensity I is logI.

A) 6.9
B) 0.7
C) 15.9
D) 5.9