[World Magnetic Model maps notating the magnetic field's intensity (top) and inclination lines, or angle of the earth's magnetic field above or below horizontal (bottom)]
[Film of a suspension of dissociated cells from trout "olfactory epithelium" (cells extracted from some unfortunate trout's nose) placed under the laboratory influence of a magnetic field rotating at a frequency of 0.33 Hz. We can see the iron-laden epithelium cell (near the center), rotating in tandem with the magnetic field. Through this procedure, scientists postulate that they have isolated magnetoreceptor cells that respond to the Earth’s magnetic field. Equipped with this sensorial compass, migratory fish may be able to feel which way is north, as well as detect small differences in magnetic field strength to navigate along global lines of inclination.]
Typically when we speak of migration, we think of monarch butterflies, people, snow geese or Chinook salmon; organisms that move from one landscape on the quest for food, procreation, bodily protection, or something else. The emphasis falls on the movement through time from one physical place to another for what is sought somewhere else. We rarely, if ever, talk about the migration of landscapes themselves, meaning the manner in which landscapes are also bodies shifting through time, in turn influencing the migration of those smaller things.
The trout compass (assuming the above study’s general validity) caught my attention as a potential illustration (perhaps an esoteric one) of those relationships. Trout have these peculiar concentrations of iron in their noses that allow them to sense a global material phenomena. The differentiated cells aberrantly push at the rest of its body to tell it which direction to go across vast expanses of aqueous geography. Like switching on a GPS receiver for the first time, the fish doesn’t ‘know’ or register that it has this technology within it – its highly attuned and place-specific historical artifacts of being. It’s cells auto-form seemingly involuntary scale-jumping relationships to an assemblage of forces much larger than itself that it comes to fully depend on. With that hardware organically calibrated near conception, it doesn’t seem to require re-tuning or adjustment.
The same isn’t true for the world magnetic model maps pictured above. Used nearly universally by both military and private institutions, the models must be redrawn every five years (the current model was completed in 2010 and will be revised in 2014) to keep up with how the earth’s magnetic field migrates:
["The famous English astronomer Edmund Halley (after whom Halley’s Comet is named) was the first person to map how compass direction varied over the globe (declination). He published the first chart of compass variations in 1701 (above), after two expeditions around the Atlantic making accurate measurements of the magnetic field." *]
Three centuries after Halley few of us (humans) still navigate with a magnetic compass, as we’ve more or less abandoned the earth’s magnetism as base material for way-finding systems. Rather its been supplanted by a far more extensively designed infrastructure embedded on the earth’s surface and outer atmosphere. As seen in the rapid evolution in how iPhones know where one is (the link is already out of date), the extent of the locational field first grew ever larger, then the grain of the weave grows tighter and tighter – from trilateration of constellations of satellites orbiting at altitudes of 12,000 miles to trilateration of wifi-bubbles. And rather than tracking that which is wholly non-anthropogenic – forces emanating from the earth’s outer core – our external-to-body compass tracks feedback from all the extensive appendages and alterations we’ve made to given surfaces. The compass reads as artifact of landscape change.