I was thinking the same thing.  Not sure what type of tech would/could do such a thing though. But what little I've looked into the mystery wave, it doesn't seem that it could be a natural phenomenon. In my past life, I was a trained audio engineer, and audio obviously deals with the science of sound waves...which is a different thing because it's sound waves as opposed to seismic waves..but it's also the same thing because the behavior of waves doesn't really change at the fundamental level (I'm excluding shit like wave/particle duality and the double slit experiment).  Sure, the medium through which waves travel (i.e. air VS water) does affect certain things, but stay with me here..different mediums don't suddenly make it possible for naturally occurring clone waves, or identical copies of one another, to be possible, in other words.  That is an entirely separate issue, and it's what makes that mystery wave so well...mysterious. If I record sounds of any event in the real world, no wave ever looks or sounds exactly like another - even if the source of the sounds is the same.  And even if you record something that sounds like it's the same to you as another take from the same sound source (like the same guitar note played on the same guitar or the same vocal melody sang by the same vocalist), when you actually compare any number of them on a computer screen, there will always be differences between them - always. The only way to get truly identical waves is to either clone (copy and paste) or to create them synthetically (for example a sine wave which is perfectly symmetrical every time, or the sounds from a drum machine, etc).  In other words, it takes some sort of man made/tech intervention to make perfectly matched/cloned waves. I'm no geologist, but I have to assume that the same principles apply to seismic waves - or any other waves - for the same reasons. Just like there's only one "you" with your fingerprints (unless you are cloned 100% perfectly) each sound ever produced in the natural world is unique.    And based on what I read, those seismic waves (or whatever type of waves they are) were identical...which pretty much negates the possibility that they were naturally occurring.