Anyone interested in metrology/ geology who can explain.....

[Aneka]

Who could explain the magnetic north pole to me? Where is it located? Why does it travel with accelerating speed since the 90s? Most articles I found are from 2019.

 

[Judge]

Published March 7, 2022:

https://www.popularmechanics.com/science/environment/a32496561/why-magnetic-north-pole-moving/
Magnetic North has always interested me given the cartographic implications. That for any number of much older American cities, you may discover how the streets all run in accordance with magnetic north up to a certain point in time. Amusing to see how the map changed then, and how streets began to be developed based on true north.

Sacramento California being a classic example. Google the street map, and notice how the center of the city (oldest part of town) adheres to magnetic north and the outlying areas correspond to true north.

 

[Aneka]

Published March 7, 2022:

https://www.popularmechanics.com/science/environment/a32496561/why-magnetic-north-pole-moving/

Thank you!

 

[Outdated]

Not something I understand very well myself and I would like to hear a more concise explanation too.

I know that the field shifts around a fair bit, so sometimes the magnetic poles drift closer to the actual poles and sometimes they drift further away. I'm not sure what causes it but I think it likely to do with shifting currents in the earth's molten core.

Last time I took any notice of it the magnetic north pole was in Canada and the magnetic south pole was near the Great Australian Bight.

The magnetic poles are where you see the auroras, Borealis in the north and Australis in the south. Ealier this year people were able to take photos of the aurora in Tasmania.

There are fossil records showing that sometimes the poles will even do a complete flip, magnetic north goes to the south pole and vice versa. This doesn't seem to have any great impact on life except for which direction water swirls in when it goes down a drain and which direction some plants spiral in as they grow.

 

[Lysholm]

the streets all run in accordance with magnetic north up to a certain point in time. Amusing to see how the map changed then, and how streets began to be developed based on true north.

I watched a documentary last night where the host said the streets of this five-thousand year old city were several degrees off of North-South and they didn't understand the significance of it. I'm like: North moved.

 

[Jeff T]

Published March 7, 2022:


Sacramento California being a classic example. Google the street map, and notice how the center of the city (oldest part of town) adheres to magnetic north and the outlying areas correspond to true north.

Fascinating! Just saw this post. I'd always assumed that the original plat was derived from the river waterfront angle.
I looked up other gold-rush cities: Marysville, Stockton, San Francisco. They all have unknown varying inclinations. The Central Valley cities that came later when the 1870 Central Pacific was laid down, all were aligned with the railroad frontage except Visalia, which predated the railroad.
Los Angeles is all over the place, the Spanish settlers adopted an "old world" rambling street system it seems?

I hope that when the poles flip again (I recall it seems we're overdue?) that the airliners and sea ships don't get messed up with chaotic change.
I wonder how the mantle currents/magnetic effect derived from? Is it the rotation of the Earth? The effect of the Moon, which apparently was MUCH closer to the Earth way back? Or just an effect of the superhot core of the planet?

 

[Outdated]

I wonder how the mantle currents/magnetic effect derived from? Is it the rotation of the Earth? The effect of the Moon, which apparently was MUCH closer to the Earth way back? Or just an effect of the superhot core of the planet?

I only know what I was taught as a child, my grandfather explained it by telling me to watch a pot of boiling soup and see the way all the carrots and bits of meat shift around.

We do have quite a few creatures that rely on the magnetic field for direction finding, from whales to birds right down to termites. Here's a picture of some magnetic termite mounds in the north of Australia. They build their mounds this way to manage temperature but they're guided by the earth's magnetic field, so some mounds face a slightly different direction to others and some even have a bit of a twist in them.

 

[Aneka]

I only know what I was taught as a child, my grandfather explained it by telling me to watch a pot of boiling soup and see the way all the carrots and bits of meat shift around.

We do have quite a few creatures that rely on the magnetic field for direction finding, from whales to birds right down to termites. Here's a picture of some magnetic termite mounds in the north of Australia. They build their mounds this way to manage temperature but they're guided by the earth's magnetic field, so some mounds face a slightly different direction to others and some even have a bit of a twist in them.

View attachment 92463

View attachment 92465

Wow, I didn't know these structures were so tall. Amazing. Looks a bit like gravemarkers though.

 

[Yeshuasdaughter]

Well, you see, this is what I taught my daughter, when she was very young:

The North Pole is situated on a gigantic glacier. The magic of Santa's Village is what makes it seem so magnetic. And as the iceberg floats around the Arctic Sea, So does the magnetic pole change position. If you calibrate your compass just right, you may be able to find Santa's Village for yourself, and get a ride home tonight at midnight, in his sleigh.

 

[Shevek]

Not something I understand very well myself and I would like to hear a more concise explanation too.

I know that the field shifts around a fair bit, so sometimes the magnetic poles drift closer to the actual poles and sometimes they drift further away. I'm not sure what causes it but I think it likely to do with shifting currents in the earth's molten core.

Last time I took any notice of it the magnetic north pole was in Canada and the magnetic south pole was near the Great Australian Bight.

The magnetic poles are where you see the auroras, Borealis in the north and Australis in the south. Ealier this year people were able to take photos of the aurora in Tasmania.

There are fossil records showing that sometimes the poles will even do a complete flip, magnetic north goes to the south pole and vice versa. This doesn't seem to have any great impact on life except for which direction water swirls in when it goes down a drain and which direction some plants spiral in as they grow.

Water swirling around a drain, and the direction of cyclones are both caused by the Coriolis effect, not magnetism. The water north and south of a drain plug only has a small differential speed due to the Earth's rotation, because the tub is small, so it is easily defeated by just swirling the water the way you wish.
There is a hypothesis that the Earth's magnetic field flips when the Sun's magnetic field goes first.