John wrote, “Only one case, Loma Prieta by Tony Frasier-Smith, gave an interesting result, and since not even the smallest detectable earthquake accompanied his observation, there certainly was not much cracking rock or fluid percolation involved.”

That case was not the first by a long way; it is just that it brought more attention to the matter, especially in the USA. I have no idea what you mean stating that no earthquake accompanied the observation, since the point was that a large earthquake shortly followed the observation, which observation was made by accident, since ULF signals were being monitored for a different purpose. Such signals are presumed to result from rock that has reached a point of nearly cracking, or from faults on the verge of breaking.

The VAN method, developed by three physicists at the University of Athens (in the Physics Dept, not the Seismology Dept) made use of ULF signals, and there was a big controversy, partly involving demands put on “prediction” to prove “correlation.” I do not know the details of that debate, but concerning a similar situation in Japan, I do know what physicists say here.

They say their funding has been completely cut as a result of vested interests, even though they were getting very good results, and that’s that. On October 18, I observed extreme levels after a very long lull, and from the 20th, worried, I contacted some people, thinking that there were stations around Niigata, but I was told that they had all been shut down. So it is no surprise you will not see any results connected to that quake, which occurred in Niigata on October 23. Observations like mine are crude and amateurish; a system of professional stations is necessary.

Similarly, there used to be a bunch of stations in Sumatra run by the Japanese. They had already been shut down too, so there was no way of obtaining data prior to that 9M quake.

So the claim that there is not enough evidence for ULF precursors rings pretty hollow in Japan, since the stations that could have provided evidence have all been shut down, after being in operation for a fairly short period of time.

Prior to the 1995 Kobe quake (today is the 10th anniversary day) huge ULF signals were observed by various people, including myself (also accidentally, in my case). This is fairly well-known and was even used as an element of conspiratorial theory – evidence that the quake was man-made. Other pre-quake observations included huge increases of ions in the atmosphere (from radon) that was not disclosed until afterwards, and animal behavior anomalies, particularly odd behavior of wild boar which I too observed several times. (Many people, including myself, consider that such behavior anomalies are associated with high ULF signals).

One Japanese physicist took the trouble to run experiments showing that intense ULF signals cause worms to come to the surface en masse, which is another thing observed before the quake.

Your statement “It is not clear there is any EM signal present to interpret” may be true for you, but for many it is very clear that there are signals to interpret, and the problem is how to interpret them. That is, how to establish or define the “precursor” nature of a signal.

So one thing I was getting at is that this same difficulty of interpretation, in addition to others, will be present in interpreting the precursor nature of sounds, if these sounds are resulting from precursor ULF signals. It may be that interpretive shortcuts may be found, such as “left ear=north” , “length of time gives distance”, etc. which does pique my interest a little.

Finally, as regards the article which Petra cited, I was merely pointing out the fact that no testing was done for EM signals under 20Hz and so this kind of signal could not be ruled out as a cause of the Taos Hum phenomenon.

Ara