In this activity, you will investigate earthquake data and explore the Richter scale as a measure of the intensity of an earthquake. You will consider how numbers on this scale compare with one another and study logarithms in the process.

USE GRAPH BELOW AND SHOW ALL WORK:

1.  How much stronger is an earthquake that measures 6.5 on the Richter scale than one that measures 6.0? How much farther away from your home is a restaurant that is 6.5 blocks away, as compared to one that is 6.0 blocks away? How are these measures similar and how are they different?

2.  Retrieve the file “EA7.1.1 Deadly Earthquakes.xls” from the CD or website. (These data were obtained from the website http://earthquake.usgs.gov/.) This file contains the date, location, and magnitude on the Richter scale of earthquakes that occurred from 1975–2003 and involved the loss of 1,000 or more lives.

3.  Sort the data in ascending order by magnitude and give the date and location of the strongest and weakest of the earthquakes on the list. (See Activity 1.2 if you do not remember how to sort data.)

Strongest:

Weakest:

4. How many times stronger was the strongest earthquake than the weakest?

5.  For each of the earthquakes listed, compute the relative energy it released using the following instructions. Recall that the relative energy E released by an earthquake of magnitude m on the Richter scale is E = 10m.

Instructions to Use Excel to Calculate Energy Released

a. In cell D2, enter =10^C2 (the ^ symbol indicates raised to a power) to calculate the relative energy of the first earthquake. Enter an appropriate title in cell D1.

b.  To calculate the relative energy as a function of Richter scale magnitude for all earthquakes, use the “drag” feature of Excel to fill the column.

6.  Here are instructions to use Excel to write in scientific notation the relative energy released by the first earthquake on the list.

Instructions to Use Excel to Write Scientific Notation. In cell F2, enter =D2 to copy the number in cell D2 (which represents the relative energy released by the earthquake) into cell F2.

Click on cell F2, go to the Format menu and select Cells.

In the Format cells window, click the Number tab and choose Scientific from the Category list. For Decimal places, enter 2.

7.  Write the number as it appears in cell F2 and also write it in standard scientific notation (using a power of 10).

8.  What is the difference between the number in cell D2 and the number in cell F2?

EA7.1.1 DEADLY EARTHQUAKE