"By analyzing seismograms from the earthquake, Seth Stein and Emile Okal, both professors of geological sciences in Northwestern's Weinberg College of Arts and Sciences, calculated that the earthquake's magnitude measured 9.3, not 9.0, and thus was three times larger. These results have implications for why Sri Lanka suffered such a great impact and also indicate that the chances of similar large tsumanis occurring in the same area are reduced."
The author of the news article doesn't understand the Richter Scale. A 10.0 earthquake is 10 times as large as 9.0 quake. The Richter Scale is logarithmic. A 9.3 quake is about 2 times as large as a 9.0 quake.
Technically, the Richter scale is not currently used for anything.
It's the Moment Magnitude scale I'm sure they're referring to in the press release.
http://wwwneic.cr.usgs.gov/neis/eqlists/eqstats.html
And the article isn't incorrect, just unclear. a 9.3 has twice the ground motion of a 9.0, but does in fact release THREE times the energy of a 9.0, as you can see from the link above.
I don't believe that the author of the article is correct, but I also don't think you are correct.
Since I am no expert, I would have to defer to someone that is.
You are correct that it is logarithmic, but the magnitude factor you state I am not sure of.
I will find out.
That's because it's a really stupid scale. Nobody understands it except the scientists who study earthquakes. It should be dumped for a simple graph from one to one hundred. It would be good for the public to understand magnitudes and they NEVER will given the perversity of the Richter obfuscation.