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Re: Order of magnitude

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>* The biggest earthquakes are (8. x) Righter magnitude and
>10000x20x1000=2x10^8.  You owe me a beer Chris.
I think I owe you a recommendation for a beer. You got fairly close 
because you got fairly lucky. ;-> So try Summit Extra Pale Ale--lip 
smackin' wonderful.

At your recommendation I ran through the calculations using your 
correlation and the heat of combustion of TNT (=820.7 Kcal/mol @ 227.12 
g/mol = 1.37 joules/Ton. 4186 J/Kcal and 10^7 ergs/joule gives a heat of 
combustion for TNT of 1.37E10 joules/ton) and came up with the following 
table (Check it out with a monospaced font like Courier):

Magnitude	  Energy     	  Equivalent
           (joules)	     Tons of TNT	  Log(Ton)
4         	6.31E+10	            5	       0.66
4.5	       3.55E+11	           26	       1.41
5	         2.00E+12	          145	       2.16
5.5	       1.12E+13	          818	       2.91
6	         6.31E+13	         4598	       3.66
6.5	       3.55E+14	        25858	       4.41
7	         2.00E+15	       145410	       5.16
7.5	       1.12E+16	       817702	       5.91
8	         6.31E+16	      4598276	       6.66
8.5	       3.55E+17	     25858009	       7.41


You get fairly close for the strong earthquakes but the agreement gets 
worse for weaker ones. The hooker is the 11.8 term in the magnitude 
correlation which affects the proportionality. Enjoy that Summit, but 
don't forget that the Richter scale isn't defined by an energy release 
rate but by a standardized seismograph reading.




Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw(--nospam--at)skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/~chrisw