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Fascinating stuff Peter,

This begs the question: what would happen to these creatures when the earth's 
magnetic field dissapears and/or becomes incoherent prior to it's regular 
polarity reversals?

I seem to recall an article in a 2007 issue of Scientific American that 
suggests that the earth's magnetic field is weakening and further, that 
several significant magnetic anomolies are developing in the southern 
hemisphere; which further suggests that a reversal is around the corner.

The implications for all life on earth does not seem promising.

Robert

----- Original Message -----
From: Peter Fogg 
Date: Wednesday, April 2, 2008 2:31 am
Subject: [NavList 4784] On the navigation of whales

>
> From: Bonner N, 1993, "Whales of the World", Blandford, pp115/6:
>
> Live strandings ... show a distribution that is related to an
> important, but little known, geophysical pattern - the total
> geomagnetic field of the Earth. Margaret Klinowska has shown that all
> the British live strandings occur where geomagnetic contours cross the
> coastline at right angles. She suggests that the whales use the total
> geomagnetic field as a map, using not the directional differences (as
> we do with a compass), but the small relative differences in total
> field.
>
> The total geomagnetic field fluctuates in a fairly regular manner each
> day, and it is possible that whales use these fluctuations as a timer
> to tell how long they have been travelling, coupled with a learnt or
> instinctive tendency to follow a field of constant strength, that is,
> to follow a geomagnetic contour. This ability might be the basis
> of a
> system of whale navigation.
>
> Klinowska noticed that live strandings tended to occur on days on
> which the daily fluctuation had been obscured by solar activity or
> other irregular changes. On the south coast of Britain, strandings
> occurred two days after a magnetically disturbed morning, while on the
> north coast it was about a day and a half later. Looking at the
> geomagnetic map, she discovered that there were two major geomagnetic
> crossroads near the United Kingdom, one about a day and a half's swim
> from the Scottish coast, the other about two days from the south
> coast. This suggested to Klinowska that the doomed whales made their
> mistake while still some distance from land, but then swam on
> regardless, following a contour till it lead them, not past the coast,
> but straight onshore. This theory could account for the often observed
> fact that beached whales, when towed back out to sea, swim to the
> shore once more. They are, it seems, convinced that is the right
> direction in which to travel.
>
> >
>


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