Hey Don-

Nice chart - I missed that one....

I've read where many folks including Chinese and Russians and others have really been putting ULF as a precursor to the test.

As your link indicates...it's a 'sometimes so' 'sometimes not so' proposition.

Maybe, as another quake related observation, it brings us back to the question of "what is an earthquake"? Of course the undeground rock fracture causing the'piezoelectric effect' is and will continue to be a "catch all" category to "explain this stuff away"....

Maybe a new paradigm/definition of earthquakes would change all that.