Answer:
[tex]I_1=40I_2[/tex]
Step-by-step explanation:
[tex]M_1[/tex] = Magnitude of 1994 earthquake = 6.7
[tex]M_2[/tex] = Magnitude of 2014 earthquake = 5.1
[tex]I_1[/tex] = Intensity of 1994 earthquake
[tex]I_2[/tex] = Intensity of 2014 earthquake
[tex]I_0[/tex] = Zero-level earthquake the same distance from the epicenter = 0.001 mm
Magnitude is given by
[tex]M_1=\log(\dfrac{I_1}{I_0})\\\Rightarrow I_010^{M_1}=I_1\\\Rightarrow I_1=I_010^{6.7}[/tex]
[tex]M_2=\log(\dfrac{I_2}{I_0})\\\Rightarrow I_010^{M_2}=I_2\\\Rightarrow I_2=I_010^{5.1}[/tex]
Dividing the above intensities with each other we get
[tex]\dfrac{I_1}{I_2}=\dfrac{I_010^{6.7}}{I_010^{5.1}}\\\Rightarrow \dfrac{I_1}{I_2}=39.81\approx 40\\\Rightarrow I_1=40I_2[/tex]
The intensity of the earthquake in 1994 was 40 times stronger than the earthquake in 2014.