Earthquake Magnitude and Logarithms

The video tutorial explains how to calculate the magnitude of earthquakes using the common logarithm of their intensity. It provides examples for three earthquakes with given intensities and demonstrates how to use a calculator to find the logarithms. The results are rounded to one decimal place, and the final magnitudes are presented.

What is the formula used to calculate the magnitude R of an earthquake?

• R equals I squared

• R equals the square root of I

• R equals I divided by 10

• R equals the common log of I

Which tool is recommended for calculating the common logarithm of the intensity values?

• A mobile phone calculator

• A standard calculator

• A graphing calculator

• The Desmos scientific calculator

What is the common logarithm of the intensity value 10,809 rounded to one decimal place?

• 3.5

• 4.5

• 5.0

• 4.0

What is the rounded magnitude for an earthquake with an intensity of 75,021?

• 5.1

• 4.9

• 4.7

• 4.5

For an intensity of 420,273, what is the magnitude R rounded to one decimal place?

• 6.0

• 5.8

• 5.6

• 5.4