Hi David:

Sure, catalog selection would be somewhat subjective as you say, but that would be about the extent of the subjectivity, and the possibilities are very limited, so I think it can be dealt with. Granted, the US has better catalogs than pretty much anywhere else. The idea would be to use the most complete catalog available for the predicted location. This would generally require us to 1. find a catalog that goes down to the low end of the prediction with regards to predicted magnitude, and 2. go back to the first occurance in that catalog of that magnitude. Once that was known, we would have a catalog that that is sensitive down to the predicted low end magnitude for the maximum period of time.

Most likely, non-US catalogs are going to be limited with regards to sensitivity, and we may likely find that we can only go down to say a 5.0.

With regards to aftershocks, I'm aware that Alan Jones does something to deal with them, but I have not idea what that process is. I would be concerned with the subjectivity with that sort of analysis, but would be interested in looking into it.

So, in the end, there may be some slight subjectivity with regards to calculating odds, but I think the value of using this as an analysis tool far outweighs that slight subjectivity. It may not be perfect, but it gives us a tool to find valuable predictions/hits. Besides, I can't think of any other way to attempt to put value on predictions. If you have any ideas, let us know!

Michael