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What happens to Google Maps when tectonic plates move? (2020)

nautil.us

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Re: What happens to Google Maps when tectonic plates move? (2020)

#31

Post by topherclay »

brendanashworth wrote: post #21
fy20 wrote: post #18

The article doesn't mention it, but how are the coordinates of property boundaries recorded in South California to take into account the drift? In my relatively tectonically stable country there is a single coordinate system for the whole country. I'd imagine you need to record distance to a local landmark or similar? And what happens when there are shifts that end up in roads split in two like in Turkey last year? h…

Property boundaries aren't delimited by GPS coordinates, but rather a surveyor's instructions on how to locate the boundary from a set of known landmarks. In most US states, the Public Land Survey System [1] gives "meridians" and "baselines" for each region serving as the regional center. Radiating out, every 6 miles, is a new "township," with its corners serving as the local landmark for property boundaries. [1] htt…

But so that means that you could lose land or gain land if enough earth moves and the relative change to the land marks is in your favor or not. But it's just not a big enough of a deal to do it a different way. I do wonder what the most significant occurrence of that is though.

Re: What happens to Google Maps when tectonic plates move? (2020)

#32

Post by smolder »

saalweachter wrote: post #19
tkcranny wrote: post #16

Earlier quoted context omitted.

From the article: > WGS 84 is a global standard tied to no one plate. In essence, it is fixed to Earth’s deep interior. Those drift vectors are based on GPS, which the article also says relies on WGS 84z

And on fixed surveying markers around the globe. You'll see them hither and yon, but my favorite is the miniature Washington Monument buried next to the real one.

For anyone curious about the buried mini-monument: https://www.atlasobscura.com/places/washington-mini-monument

Re: What happens to Google Maps when tectonic plates move? (2020)

#34

Post by teruakohatu »

perotid wrote: post #9

FWIW, global drift vectors by NASA: https://sideshow.jpl.nasa.gov/post/series.html

If you want to see an interesting one in my country:

https://sideshow.jpl.nasa.gov/post/links/KAIK.html

2016 Kaikōura earthquake: https://en.wikipedia.org/wiki/2016_Kaik%C5%8Dura_earthquake

Re: What happens to Google Maps when tectonic plates move? (2020)

#36

Post by dns_snek »

jerzmacow wrote: post #14
dhosek wrote: post #13

I remember having a hand-held Garmin GPS unit back in the '00s that I used on a trip to Berkeley from Los Angeles (one bonus was that the speedometer in my car didn’t work¹ so I was able to use it as a speedometer for the trip). The location that it showed on the map was consistently off by about 50 feet. I wonder now if this was a tectonic drift or just an inherent inaccuracy of the unit. ⸻ 1. When I think back to t…

Back in the day GPS was intentionally offset so countries couldn't use it for weapons.. well except it's owner of course!

It seems like the intentional degradation didn't work as intended in the first place and the inaccuracy could be corrected with little effort - at least for someone who had the resources to use it for weapons systems, so it only affected civilian use cases.

> Because SA affects every GPS receiver in a given area almost equally, a fixed station with an accurately known position can measure the SA error values and transmit them to the local GPS receivers so they may correct their position fixes. This is called Differential GPS or DGPS.

https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...

Re: What happens to Google Maps when tectonic plates move? (2020)

#37

Post by epivosism »

jerzmacow wrote: post #14
dhosek wrote: post #13

I remember having a hand-held Garmin GPS unit back in the '00s that I used on a trip to Berkeley from Los Angeles (one bonus was that the speedometer in my car didn’t work¹ so I was able to use it as a speedometer for the trip). The location that it showed on the map was consistently off by about 50 feet. I wonder now if this was a tectonic drift or just an inherent inaccuracy of the unit. ⸻ 1. When I think back to t…

Back in the day GPS was intentionally offset so countries couldn't use it for weapons.. well except it's owner of course!

related: a market summarizing what I know about China's intentional map offset laws, specifically on whether Google will continue following this (only 4 bettors, not very meaningful yet) https://manifold.markets/Ernie/will-google-maps-stop-followi...

Re: What happens to Google Maps when tectonic plates move? (2020)

#38

Post by epivosism »

I often think about a scifi story where after X million years, somehow familiar humanity survives, and two plates containing land with VERY different natural flora and fauna approach each other - for example, california, home of many native plant defenders, and australia. As they get closer than 50 miles, news would start to mention making sure not to cross-transplant animals and plants. Under 20 miles, the wind and storms would do some work already, but people on both sides may still be resisting. But the moment they actually touch for the first time, some great treaty may shimmer into enforceable existence, changing the future of that whole world.

Or else, they'd just build fences, forbid anyone from living on the coast, and maintain this artificial continental boundary forever...?

Re: What happens to Google Maps when tectonic plates move? (2020)

#39

Post by londons_explore »

wombatpm wrote: post #27
dhosek wrote: post #13

I remember having a hand-held Garmin GPS unit back in the '00s that I used on a trip to Berkeley from Los Angeles (one bonus was that the speedometer in my car didn’t work¹ so I was able to use it as a speedometer for the trip). The location that it showed on the map was consistently off by about 50 feet. I wonder now if this was a tectonic drift or just an inherent inaccuracy of the unit. ⸻ 1. When I think back to t…

Owning a junk car is a rite of passage to adulthood hood. You learn what to do when a car overheats, how to change a tire, replace a fuse, recognize the difference between burning oil and radiator fluid, how to jump start a car, and how to call a tow truck. Important life skills

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Re: What happens to Google Maps when tectonic plates move? (2020)

#40

Post by ffsm8 »

epivosism wrote: post #38

I often think about a scifi story where after X million years, somehow familiar humanity survives, and two plates containing land with VERY different natural flora and fauna approach each other - for example, california, home of many native plant defenders, and australia. As they get closer than 50 miles, news would start to mention making sure not to cross-transplant animals and plants. Under 20 miles, the wind and…

Humanity won't be alive by that time.

It's a interesting setting to explore in fiction, but has no chance of becoming reality.

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