While researching the Amundsen 1911 expedition to the S Pole, I came across the NOAA Magnetic Field Calculators and Historical Magnetic Declination View web sites.
I noticed that the Historical 3d Viewer blanks out results within a few degrees of the geographic poles, but the calculator returns results that don't make sense to me. For example, if you enter 90S lat values and and various lon values for 1911 it gives the following magnetic declinations:
Lat 90s, Lon of 150w gives 127.7
Lat 90s, Lon of 160w gives 137.7
Lat 90s, Lon of 170w gives 147.7
Obviously lon at 90S is undefined so why would it return these results? Using lat of 89.9 to avoid potential math problem gives similar results. I sent the admin a note about this but haven't received a reply. If it was to match the 3d Viewer it would return null within a degree of so of the pole.
Thanks, Tom Kreyche
At 22.29 degrees west, 90.0 degrees south, magnetic declination is 0.0 degrees E and at 157.71 degrees east, 90.0 degrees south, declination is 180 degrees E. Strange, huh?
Research Isogonic Lines and then ask any AI whether magnetic declination varies with longitude at or near the south pole.
That's a great question! Thanks for asking it!
The magnetic poles are not 90n or 90s, plus they wonder like a drunken sailor. Lets just hope we don't live through a flip or a plasma event while our magnetic field is weakened as it seems to be now.
Lets just hope we don't live through a flip or a plasma event while our magnetic field is weakened as it seems to be now.
Lifted directly from ChatGPT (so consider the source):
A magnetic polarity reversal would:
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Likely unfold over thousands of years.
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Cause temporary weakening of Earth’s magnetic field.
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Lead to increased radiation exposure, technology disruptions, and navigation challenges.
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Not pose a threat to human survival or cause mass extinction.
It’s a geophysical process, not an apocalyptic one — though it would require significant adaptation by modern technology.
I think that I prefer the ChatGPT answer to this one: https://www.igpppublic.ucsd.edu/~cathy/Publications/Constable_frontiers.pdf
I was curious about the birds.
If the magnetic poles reversed, most birds would still fly south during migration, as they primarily use the angle of inclination (the "dip" of the magnetic field lines) rather than the polarity (north or south) to navigate. While some birds might experience initial confusion, the overall impact on migration patterns is expected to be minimal.
Put another way, it takes a rare bird to confuse angle of inclination with polarity.
Plus or Minus 🙃