That is apparently the basis for his procedure. But the actual earthquake location determinations require some calculations which I myself have not seen. I believe that Shan is a physicist. And his procedure is based on some research by another physicist or perhaps a geologist. So I would expect that between the two of them they have the technical qualifications needed to develop such a procedure.

In theory, if a fault zone directly beneath you and close to the surface is getting ready to fracture then the ground in the vicinity might be expected to make a measurable shift in one direction or the other just before the earthquake. The problem here is that someone has to do an evaluation of the procedure and then generate some publications etc. And I don’t think that Shan has the time available needed to do that.