Earthquake Magnitude how to

[colorado]

explain?

Students think a 5 is 5x bigger than a 1.

I explain that a 2 is 10x bigger than a 1 and a 3 is 10 x 10 (100x)
bigger and so forth so a 5 is 10x10x10x10 or 10,000x bigger than
a 1 (Richter scale - movement?)

Now there is he momentum scale which measures the energy. Where did the number (32) come from and is it also a multiple among itself as in comparing a mag. 3 to a mag. 1
that would be 32 x 32 (1024x more energy)?

and what is the unit for this energy? Is it a joule? megajoule?

This is my question? ;D
Colorado

[chromite]

It's [The Richter Scale]not a true measure of energy yet a scale measuring amplitude of displacement measured by a particular type of seismograph. Probably related to the spring constant of that particular seismograph. Show them a logarithmic graph and have them plot some points vs a regular Cartesian graph. I'm sure you can do that on an overhead.

The Moment Magnitude Scale is measured in dynes. A dyne is "the force required to accelerate a mass of one gram at a rate of one centimetre per second squared," and is equivalent to 10^-6 Newtons.

[chromite]

Great web resource right here:

earthquake.usgs.gov/

[rocksmarsandstars]

Sorry about the late notice-I just received this 10 min. ago:

www.jpl.nasa.gov/education/index.cfm?page=262

Is a link that will explain when and where, and how to submit questions that your students have about earthquakes/tsunamis.
This is an opportunity for student-scientist interaction that sounds like a whole lotta learnin' goin' on!
Ken

[downeast]

Another activity you might try is the virtual earthquake. Here the students take the role of seismologists and compute the magnitude of your choice of earthquakes. Then also compute the location (epicenter) via triangulation.

Go to www.scienmcecourseware.com/virtualearthquake

It's free and guides the student through the process. In the end, if they get it correct, the get a Virtual Seismologist certificate that they can print out. I use this in my Physical geology course at the local community college. It will take approximately 20-30 minutes to complete.

Downeast