NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: On the navigation of whales
From: Robert Eno
Date: 2008 Apr 02, 10:44 -0400
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 FoggDate: 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. > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---