I suggest you study strategerist's posts. He, and later djf, shine as two who really know what they're talking about. I suspect both are affiliated with either the volcanology or geology communities (possibly NPS employees).
Heh, I took Geology 101 and that was about it. I just try to read as many scientific papers on line as I can (people should take the time they waste listening to Art Bell and do that instead, while SOME papers will be dense with incomprehensible equations, many papers are readable once you learn some of the basic vocabulary), and I attempt to research something through Google as best I can before I start commenting on it (which doesn't take that long, and fortunately I can read fast.) Key to that is avoiding kook science sites in favor of government and university sites.
Unlike weather, I don't have any geologist friends; I do know some real meteorologists I plug for information at times.
I'm still a bit at sea relatively in geology. I'm not really confident of being able to tell a harmonic tremor trace from a regular trace, or whether there actually have been any harmonic tremor traces (I keep hearing of interviews where a geologist mentions it but the official CVO updates never mention any.
djf responds (blushing):
Thanks. Actually, I'm a bit twiddler, math and comp-sci major, but I have been studying the hard sciences for most of my life.