When I was working with the Nebraska Conservation and Survey in 1985, we noticed
an odd, but related phenomena. About two days before the Mexico City earthquake
which was Mw 8+ about 2500 km south of Nebraska, the oil and water wells in the
southern part of the state suddenly dried up and began producing at about one-quarter
their normal output. This continued until the Mexico City earthquake. After the quake,
the well began producing at twice the rate they had before the quake.
We looked at the water well levels from about 100 wells with digital and analog
recorders which were in operation at the time of the earthquake. Some showed
a very strong sinusoidal variation in the water level beginning before or at the
time of the earthquake.
At the time our theory was that the huge Ogallala aquifer which underlies much
of the state of Nebraska got pushed. This produced something like a very slow tidal wave
in the underground water and oil which produced the observed effect. The effect
before the earthquake, however has yet to be explained. The Ogallala aquifer
contains as much water as Lake Superior, so a very large effect was occurring.
You might want to think of how this relates to the Geyser problem.