I've been checking this map regularly for years: [link to www.sws.bom.gov.au]

Problem is, I don't really know what I'm looking for. I've done some reading about the relationship between EQs and the ionosphere, but basically found what you noted above- that both positive and negative anomalies can appear before a quake. I've tried to notice if the readings are really high or really low when bigger activity occurs, and I have felt there was a correlation, but other times nothing happened when those same readings were present.