Dear Bufo Bufo and group,
There are indeed some strange scientific papers
about.
It seems to me that it would be best to study
links between VLF propagation and earthquakes, and between VLF propagation and
toad breeding patterns seperately. But the author is clearly interested in any
ability to predict earthquakes found in animals.
I had not heard of any effect
of earthquakes on VLF before, although it is true that there are many
factors which affect the ionosphere.
The suggestion is not that the earthquake emits a
VLF signal, rather that it disturbs the ionosphere, so that VLF signals are no
longer reflected across the "sky". The main things which affect the ionosphere
are solar radiation, the solar wind and the earth's magnetic
field.