The magnitude, M, of an earthquake is defined to be M=log l/s, where l is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and S is the intensity of a "standard" earthquake, which is barely detectable. Which equation represents the magnitude of an earthquake that is 10 times more intense than a standard earthquake?

M = Log (10S/S)

Step-by-step explanation:

We are told that the magnitude, M, of an earthquake is defined to be;

M = Log l/S

Where I is intensity and S is standard earthquake.

Now, we want to find the magnitude of an earthquake that is 10 times more intense than a standard earthquake

Since 10 times more intense than standard earthquake, it means that;

I = 10S

So plugging in 10S for I in the original equation for magnitude gives;

M = Log (10S/S)