Question

The magnitude, M, of an earthquake is defined to be M=log I/S, where I 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. What is the magnitude of an earthquake that is 1000 times more intense than a standard earthquake? Use a calculator. Round your answer to the nearest tenth.

A) 2
B)3
C)4.5
D)6.9

Answer 1

b

Explanation:

Answer 2

The answer is option B

Explanation:

We need to find the magnitude of an earthquake a 1000 times more intense than a standard earthquake

Be

S, the intensity of a “standard” earthquake,

I intensity of new earthquake

I = 1000*S

Then,

M=log (I/S)

M=log (1000*S/S)

M = log (1000) = 3