Science Forums 2

[FrankM]

When Hertz did his experiments many years ago, he demonstrated that a pulse of electricity through a wire could be detected at a distance. The "charge sheet" and associated current created during a seismic event is somewhat like a current pulse in a wire, as it generates an electric field that can be detected at a distance. The earth-ionosphere connection creates an interesting condition that complicates matters significantly. When the area of the seismic event goes "positive" the ionosphere above it goes "negative", which indicates a field reversal. This field reversal is not a nice sine wave pulse, but is dictated by the seismic event period with all its intensity variations.

The DEMETER sateillite is sensing electromagnetic pulses, but is this from the in-earth currents or from the earth-ionosphere field reversal?

Various types of ground instruments are picking up ultra-low frequency pulses also, some using traditional sensing coils and others "earth antennas". Unlike the DEMETER satellite, that uses 3-axis sensing coils, the vast majority of the ground sensors are single axis (this includes the majority of ULF/ELF afficionados) and those using "earth antennas" (they take a lot of real estate).

Many of the traditional seismologists are still using sensors that detect only "mechanical" seismic changes and are slow to recognize (many ignore) the electrically dynamic characteristics of seismic events.

We have a lot to learn.