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    Re: On the navigation of whales
    From: Robert Eno
    Date: 2008 Apr 02, 10:44 -0400

    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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