Chapter 4.5, Problem 1E

Reminder Round all answers to two decimal places unless otherwise indicated.

Earthquakes in Alaska and Chile In 1964, an earthquake measuring $9.2$ on the Richter scale occurred in Alaska.

a. How did the power of the New Madrid earthquake described in Example 4.12 compare with that of the 1964 Alaska earthquake?

b. In 1960 an earthquake occurred in Chile that was $2$ times as powerful as the Alaska quake. What was the Richter scale reading for the Chilean earthquake?

EXAMPLE 4.12 COMPARING SOME FAMOUS EARTHQUAKES

On December 16, 1811, an earthquake occurred near New Madrid, Missouri, that temporarily reversed the course of the Mississippi River. This was actually one of a series of earthquakes in the area, one of which is estimated to have had a Richter magnitude of $8.8$.The area was sparsely populated at the time, and there were thought to be few fatalities. On October 17, 1989, a calamitous earthquake measuring $7.1$ on the Richter scale occurred in the San Francisco Bay area. The earthquake killed $67$ and injured more than $3000$.

Part 1 How much more powerful was the New Madrid quake than the 1989 San Francisco quake?

Part 2 If an earthquake $1000$ times as powerful as the 1989 San Francisco earthquake occurred, what would its Richter scale measurement be?

Part 3 On December 26, 2004, an earthquake $2$ times as powerful as the New Madrid quake struck the Indian Ocean near Indonesia. It caused a tsunami that resulted in the deaths of hundreds of thousands. What was the Richter scale reading for this quake?