Hydroseismicity - a viable trigger mechanism in the New Madrid seismic zone?

A pressure wave, initiated by water loading and propagating downward through subsurface water contained in fractures, has been hypothesized as a mechanism for triggering earthquakes along pre-existing faults at depths up to 15-20 km. Such a triggering wave might evidence itself by a coincident wave of descending seismicity. In the New Madrid region, seismicity has been reported to correlate with river stage, but usually with a lag of one to several months. River stage data from New Madrid and earthquake data from the St Louis University's microseismic network were examined for evidence of a time-lag in seismic activity with depth during the interval from Jan. 1, 1978, to May 31, 1987. No evidence for a seismicity wave was found. -from Authors