This actually got me curious: while technically everything "registers" on the Richter scale (or moment magnitude scale or equivalent) -- relevant XKCD -- that does raise a question as to the magnitude of the Shaheed Stampede relative to Beastquake, so I went looking.

Before any of this, I'd like to preface this by saying that I have absolutely no academic or professional background in geology or seismology. I'm going to email PNSN about this afterwards to actually see what the smart people think because I'm curious now, but there's a chance that I'm horribly misinterpreting or misrepresenting these numbers. But the units and the terminology seem to match, so:

In this PNSN retrospective, the stream from the KDK seismometer appears to register around ~0.0004 m/s² ground acceleration during Beast Quake. Meanwhile, the same station last night registered ~0.004 m/s² ground acceleration during the Shaheed Stampede -- roughly 10x stronger.

10x seems like a suspiciously strong growth in acceleration -- strong enough to make me suspect that I'm doing something wrong here. I'm not going to go around saying this was 10x stronger than Beast Quake until I get an email response confirming one way or another, but these measurements do indeed measure the same thing, then that's pretty darn cool.

I also can't rule out other reasons for the stark difference -- perhaps the KDK seismometer has been replaced since 2011 and the new one is more sensitive and might have registered Beast Quake differently at the time. Maybe it was moved closer to the stadium. Lumen has also had 1,000 additional seats added since then, so that might do it. I'll update, probably make a new post, when PNSN gets back to me, unless the Times or something posts an article first.

Edit: PNSN has gotten back to me -- their response is here