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Interesting fact: the magnetic variation in Canada changes at a more frequent rate, and some northern airports got tired of updating their runway numbers every
by mfkp 4y ago
Interesting fact: the magnetic variation in Canada changes at a more frequent rate, and some northern airports got tired of updating their runway numbers every year or two so they now use true instead of magnetic headings (I believe indicated on the runway numbers like 17T to indicate true instead of 17 which would indicate magnetic).
- bpye 4y agoNOAA has a neat tool to determine the difference (declination) [0]. Looks like it's about 16° for me in Vancouver, BC. [0] - https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#declination https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#d...
- colechristensen 4y agoAdditionally, the magnetic pole is actually in northern Canada
- bruce511 4y agoTechnically there's a place (well, line) where North is one way, but the compass points south. Flying a great-circle route that intersects the North Pole, and magnetic North Pole, would mean travelling both north and south at the same time for a period. It's perhaps unfortunate that we live in an era where they are "close enough" that we have one word (North) for two different directions.
- josephcsible 4y ago> we live in an era where they are "close enough" that we have one word (North) for two different directions. Is it possible for the magnetic poles to ever exist far from the geographic poles? (I know the magnetic field could have been the opposite polarity, or not existed at all, but in either of those cases, we still wouldn't have gotten another word.)
- wolrah 4y ago> Is it possible for the magnetic poles to ever exist far from the geographic poles? The north magnetic pole has been south of 70 degrees as recently as the mid-1800s and the south magnetic pole is currently north of 65 degrees. Every half million years or so the whole thing goes nuts for a while and reverses.
- colechristensen 4y agoDuring polarity flips it can be anywhere but you have to really well define your terms as to what you count as a pole. I don’t think the exact mechanics of the magnetic field are super certain, but the general idea is that the rotation sort of pins the poles nearish to the axis but there’s been some significant variation historically.
- roter 4y agoWhere I sail in eastern Lake Ontario, there are some wild magnetic anomalies [0,1]. [0] https://en.wikipedia.org/wiki/Charity_Shoal_crater https://en.wikipedia.org/wiki/Charity_Shoal_crater [1] https://craterexplorer.ca/charity-shoal/ https://craterexplorer.ca/charity-shoal/
- jacquesm 4y agoAsteroid impact site? There might be a very large metal deposit close to the surface (like in Sudbury) that upsets the local magnetic domain.