I followed the link as well as others. Interesting, however I did not find their analysis of the 2 spikes convincing, particularly after I found the original article they reference. I also went back and checked out who the American Free Press is. Found this in part of who they were:
In the United States today, it is a select handful of super-rich families and tightly-knit financial interests—a plutocratic elite—who own the Big Media and who control the government through their ownership of that media. . . . Every single one of the major media outlets is controlled by this powerful interlocking combine.
These folks seem a little on the conspiracy theory side of the house. This concerns me as far as any bias they may bring to the data. So I looked at the available seismic data, absent the whole data set. The published seismograph does kinda shows two peaks (from our buddy station PAL). The British article referenced interviews with seismologists and their comments did not indicate that the pattern supported the basement bomb theory as in that there was anything unusual. I don't think that the first peak represents an explosion as they infer. Remembering the detailed studies done, the mechanism for the building collapse did not require assistance in that manner. My take is that the first peak represents the initial failure, then it is attenuated as the rest of the structure falls culminating in the second peak.
Thanks. It seemed that a small double spike could be a natural signature to the event.
If you need a good double spike for reference, I'll dig one up for you. The Galapagos seismograph history is full of them.
I'll trust your judgement as to the geological issues.
Thanks again!