Talk:2098: Magnetic Pole

GPS relies on satellites not the magnetic pole, so it wouldn't be affected.

I originally mentioned that modern GPS receivers like in smartphones may integrate the compass, gyro, and GPS to provide higher-quality location data using heuristics, which may get fouled-up if the pole moves too far, but I wrote it in too playful a manner and it has been deleted since. There was no citation anyway; it was just a vague memory. 162.158.79.245 06:08, 15 January 2019 (UTC)

So, GPS receivers don't need magnetic poles... but what about the GPS satellites? GPS works being them transmitting their exact location, so they need so way of knowing what that is. JamesCurran (talk) 22:58, 14 January 2019 (UTC)

I was wondering about that. Just added ^{[citation needed]} to that and a couple of other alleged facts that should really be cited if true, and removed if not. 108.162.216.208 20:35, 14 January 2019 (UTC)

It was speculated that reversals were linked to mass extinctions. This would make the alt-text appear to be a bit blase - but " Statistical analysis shows no evidence for a correlation between reversals and extinctions." so it seems we will probably be OK. It does seem odd that GPS wouldn't be calibrated against fixed ground positions. Baldrickk (talk) 22:06, 14 January 2019 (UTC)

I expect we'll be fine, but don't a lot of migratory critters use the Earth's magnetic field for navigation over very long distances? I mean, it's not as though they check a calendar and say, "Oh, hey, winter's coming, I guess I'd better head North." They just go in the direction they are 'programmed' to go when they start to feel the urge to do so. So... If the poles reverse (or whatever else) aren't they going to go the wrong direction? There are lots of other species that rely on those migratory species for their lunch. Yeah, I can imagine that there could be a lot of problems. Assuming, of course, that what I read about migratory species using the magnetic field of the Earth for navigation is true.162.158.79.143 02:39, 15 January 2019 (UTC)

I don't believe any "location systems" depend on magnetic field for their accuracy, other than a magnetic compass. As noted above, GPS is calculated numerically from signals received from satellites, so the only effect the magnetic field could have on that is if it somehow disrupts the broadcast of the satellite radio signals. Similarly, LORAN calculates location based on radio signal, from towers on land. There are others as well, and I'm pretty sure none that depend on the location of the magnetic pole. GPS in general is not calibrated to fixed ground positions, but there are enhancements to GPS that do. But those still use radio broadcasts from towers whose locations are known, and don't need to take into account the location of magnetic north. Lnthomp (talk) 22:28, 14 January 2019 (UTC)

I agree that the way it is currently phrased is misleading (to the point of being wrong), but some "location systems" use multiple factors to increase their accuracy. A good smartphone will use GPS together with signal strengths to wifi routers with known locations together with its compass to increase accuracy above that which it could obtain from GPS alone. I've only taken little glimpses into the issue professionally but if I were making an algorithm for such a thing I'd also use input from the accelerometers. In any event, I'd most certainly use the built-in compass. Cheap estimation of direction of travel. Of course I'm just being pedantic with all of that. The difference in accuracy for such a scenario would most likely be minor to the point that nobody would notice. I just kind of think the algorithms that try to combine all that sensor data are cool. --162.158.62.51 01:24, 15 January 2019 (UTC)

It's navigation systems rather than location/positioning systems that rely on magnetic field (although both are often combined). You need a compass to know which direction your are facing and how to go to your destination.141.101.104.11 11:32, 15 January 2019 (UTC)

Granted no one has ever experienced and documented a magnetic reversal event, however, would it be possible for the magnetic flux to cause errors on magnetic media? (eg HDD, credit cards, floppies, cassette, VHS, etc) If it were a cause for alarm, would a faraday cage be useful in protecting against the effects? 172.68.34.34 23:05, 14 January 2019 (UTC)

Faraday cages attenuate electric, not magnetic, fields. I think magnetic shielding involves thick, rounded material with high permeability such as iron, steel, mu-metal, often placed inside a faraday cage to prevent RF signals from saturating the permeability; never done it myself though. 162.158.79.245 06:13, 15 January 2019 (UTC)

No. Magnetic media would not be affected. Geomagnetic field strengths are orders of magnitude weaker than those used to write to magnetic media. --162.158.62.51 01:27, 15 January 2019 (UTC)

The biggest issue during a magnetic pole reversal will be the loss of the Van Allen belt, frying all of us. RandalSchwartz (talk) 02:39, 15 January 2019 (UTC)

Unlikely to literally fry us, but there could definitely be damages on the electrical grids around the world as the magnetic field is weakened during the transition. Probably also a rise in radiation-induced cancers.141.101.104.11 11:32, 15 January 2019 (UTC).

GPS and Solar weather citation - worth a read. Basically, the ionosphere disturbance from a changing Earth field (analogous to a changing solar wind) leads to notable inaccuracy and service disruption. 108.162.221.167 23:12, 14 January 2019 (UTC)

We'll have to renumber all our runways, which will be annoying. 162.158.58.111 04:27, 15 January 2019 (UTC)

actually, several runways have already had to have been renumbered because of change in the magnetic poles.162.158.79.143 05:19, 15 January 2019 (UTC)

Wait, "geomagnetic reversal in the next few decades"? Last I checked, it was scheduled to happen in the next few millennia. Have there been new data? 141.101.104.131 09:00, 15 January 2019 (UTC)

Reversals appear to happen randomly, so there's no way to know when the next one will happen. Even if the last one happened about 800 000 years ago, there have been periods of tens of millions of years without reversal.141.101.104.11 11:32, 15 January 2019 (UTC)

800 000 = 0. Lysdexia (talk) 16:08, 15 January 2019 (UTC)

Not when the fields can reverse as often as 5 times in a million years.141.101.77.128 16:37, 15 January 2019 (UTC)

https://www.sciencedaily.com/releases/2012/10/121016084936.htm might shed some light on things. In any case, “scheduled” is definitely the wrong word. 172.68.142.77 13:49, 15 January 2019 (UTC)

What about the SOUTH magnetic pole? 162.158.186.54 15:29, 15 January 2019 (UTC)

We should mention the other comic with similar reaction: https://xkcd.com/2029/ 141.101.77.56 11:45, 16 January 2019 (UTC)

I'm glad we decided to work on that. Now a lot of geography-students will be a lot less confused when the magnetic field comes up.

I think a mid-latitude aurora would be related to https://xkcd.com/2233/ 172.68.132.195 15:09, 19 April 2021 (UTC) 76.102.149.55