Story about Nobel laureate Georges Charpak's work here. Being from Pennsylvania, I thought only certain parts of the world with lots of uranium-containing pitchblende in the bedrock (like Pennsylvania) were uniquely afflicted with radon emissions. (Hat tip Boing Boing).
To join the earthquake sensor network (geology's answer to SETI) go here.
To read about other as-yet unexplained phenomena associated with earthquakes, go here.