correlation between seismic activity & VLF propagation

There is an article in the current EOS* on "Preseismic
Lithosphere-Atmosphere-Ionosphere Coupling" describing the
relationship between large earthquakes and ionospheric anomalies.
Author is M. Kamogawa. Kamogawa cites several studies that show
significant electron density depression, anomalies in the intensity
and phase of transmitted LVF waves, and variations in the terminator,
sunrise & sunset, times from VLF transmissions up to 11 days before an
M > 6 earthquake He claims these earthquakes were "highly correlated
with VLF anomalies occurring a few days prior". He/She then goes on
to postulate a selection of proposed mechanisms for causal phenomena.
The author concludes that "... atmospheric-ionospheric anomalies before
the earthquakes do exist and their further investigation...remains an
important research endeavor. Determining these connections possibly
will aid with understanding and predicting seismic activity.

At least the changes in sunrise/sunset times and possibly the anomalies in
signal strength should be within capability of the SID monitors to detect.

Debbie

* M. Kamogawa, "Preseismic Lithosphere-Atmosphere-Ionosphere Coupling";
EOS, Transactions of the American Geophysical Union, volume 87 #40,
3 Oct 06
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