Question

(a) Find the magnitude of an earthquake that has an intensity that is 35.25 (that is, the amplitude of the seismograph reading is 35.25 cm). (Round your answer to one decimal place.)

(b) An earthquake was measured to have a magnitude of 4.9 on the Richter scale. Find the intensity of the earthquake. (Round your answer to one decimal place.)

Don't bother answering if you won't give an explanation :)

Answer 1

#1

So

Formula is

• M= log(A/0.001)

A is amplitude and M is magnitude

• M=log(35.25/0.001)
• M=log(0.03525)
• M=log3.5-log10^{-4}
• M=log3.5+4
• M=4.54

#b

So

• 4.9=log(x×10³)
• 4.9=logx+3log10
• logx=4.9-3
• logx=1.9
• x=antilog(1.9)
• x=79.4