“Solid as a rock” is an expression which none of us
would argue with. We may think that the metaphor shouldn’t be applied to our
favorite bank noire as we know that
it isn’t really solid let alone “as a rock”. Seemingly, even living in a
geologically challenged region like the ring of fire doesn’t lessen our belief
in the solidarity of rock. However, beneath our feet things are moving, and once
in a while (thankfully a long while) there’ll be an earthquake or a volcanic
eruption.
Earthquakes in particular catch us by surprise, but
often the animal world pick up much earlier than we do that something is afoot.
It can be days or even months ahead of the actual event. The BBC reviewed a
recent paper by Grant et al that is
published in the International Journal of Environmental Research and Public
Health with both a possible reason why our animal friends head for the hills
and a suggestion that we could plug into their behavior as an indicator of
something of earthshaking importance to come (1,2).
Grant was studying Italian toads at mating time in
a pond near L’Aquila in 2009. These were just the usual run of the mill Italian
toads called Bufo bufo, and were
getting on with their business of chasing as many females as possible. There
had been plenty of rain and the girls were cooperating until a few days before
the earthquake occurred. They abandoned their activity and headed out of the
pond. The epicenter of the quake was about 50 miles away.
Prior
to an earthquake, huge pressures have built up, putting rock under great stress. Scientists at NASA have also been putting rocks under a
lot of stress in recent times and shown how imperfections in the silicate
crystal structure can cause peroxy bonds to break so the rocks act like a
battery with charge migration occurring through the rock. The charge can
migrate at very high speeds through the silicate structure to large distances.
Where there is a groundwater/rock interface,
hydrogen peroxide can be produced which is strong oxidizing agent. Getting your
eggs oxidized would seem to make the whole mating activity pointless.
If the rock
runs out and there is just air, positive ions are produced. We, and other
animals, don’t like positive ions very much. They raise our serotonin levels
and that can give us migraines. Remember that negative ions lower our serotonin
levels and that relaxes us and reduces our anxiety.
Maybe it was the change in serotonin levels that
caused the hibernating snakes in Haicheng to wake up and head out into the
freezing countryside to their demise several months prior to the 1975
earthquake. A migraine might have been preferable to getting your tail frozen
off, though.
