Naked Science Forum

Life Sciences => The Environment => Topic started by: trigger on 24/11/2008 11:59:16

Title: How much more powerful is an earthquake of magnitude 7 than a Richter scale 5?
Post by: trigger on 24/11/2008 11:59:16

Hi all, can anyone please tell me:  How many times greater is the maximum ground motion of a magnitude 7 earthquake compared with that of a magnitude 5 earthquake?

Many thanks trigger.

Title: Re: How much more powerful is an earthquake of magnitude 7 than a Richter scale 5?
Post by: dentstudent on 24/11/2008 12:02:10

I think I'm right in saying that it's a log scale, and so a 6 is 10 times stronger than a 5, and a 7 is 10 times stronger than a 6; therefore a 7 is 100 times stronger than a 5.

As ever, Wiki has some good stuff....

http://en.wikipedia.org/wiki/Richter_magnitude_scale

Title: Re: How much more powerful is an earthquake of magnitude 7 than a Richter scale 5?
Post by: RD on 24/11/2008 12:05:57

The Richter scale is a logarithmic scale (base 10),
 so the amplitude of the motion of a 7 is 100 times the amplitude of a 5   (7-5=2, 10²= 100).

Title: Re: How much more powerful is an earthquake of magnitude 7 than a Richter scale 5?
Post by: trigger on 24/11/2008 12:07:31

Thank you so much for your help. I hope i can pick your brains again in the future