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Magnetic field reversal

wildlife, gardening, environment, Rural living, Pets and Vets
88V8
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Magnetic field reversal

#390823

Postby 88V8 » February 28th, 2021, 10:05 am

Interesting article about the earth's magnetic field... how it periodically reverses .... and the effect on climate and life on earth

....current movements of the north magnetic pole across the Northern Hemisphere as a potential warning sign.
"This speed – alongside the weakening of Earth's magnetic field by around 9% in the past 170 years – could indicate an upcoming reversal. If a similar event happened today, the consequences would be huge for modern society. Incoming cosmic radiation would destroy our electric power grids and satellite networks."

https://newatlas.com/environment/ancien ... ent-chaos/

V8

bungeejumper
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Re: Magnetic field reversal

#390831

Postby bungeejumper » February 28th, 2021, 10:27 am

And that's not all. Watch out for the South Atlantic Anomaly, folks. Localised reverse polarity is with us today! :?
https://www.nasa.gov/feature/nasa-resea ... etic-field
“...a localized field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions.” The infallible Wikipedia says that the anomaly has already confused space shuttles, although its responsibility for plane crashes in the region is still unproven.

Still, it takes your mind off Covid, doesn't it?

BJ

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Re: Magnetic field reversal

#390943

Postby XFool » February 28th, 2021, 6:28 pm

88V8 wrote:Interesting article about the earth's magnetic field... how it periodically reverses .... and the effect on climate and life on earth

https://newatlas.com/environment/ancien ... ent-chaos/

Um... Some dodgy stuff written in that article, IMO!

"Fossilised tree"? So why does it appear to be made of wood? Carbon dating? So, made of carbon, i.e. wood! Was it the Neaderthals who cut it down with their chain saws then? :)

I see from the comments (ignoring the usual nuts) some readers picked up on this. Trouble is, what else was written here by somebody who didn't really understand what they were writing about? It would be interesting to know what the true facts are.


PS. Then again, perhaps not! Fossilised does not mean petrified, so I guess it could be described as a "fossil" tree. :oops:

XFool
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Re: Magnetic field reversal

#390960

Postby XFool » February 28th, 2021, 7:44 pm

XFool wrote:PS. Then again, perhaps not! Fossilised does not mean petrified, so I guess it could be described as a "fossil" tree. :oops:


Then again: https://www.collinsdictionary.com/dictionary/english/fossil

COUNTABLE NOUN
A fossil is the hard remains of a prehistoric animal or plant that are found inside a rock.

So I think I'll give up...

Nimrod103
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Re: Magnetic field reversal

#390998

Postby Nimrod103 » February 28th, 2021, 10:46 pm

XFool wrote:
88V8 wrote:Interesting article about the earth's magnetic field... how it periodically reverses .... and the effect on climate and life on earth

https://newatlas.com/environment/ancien ... ent-chaos/

Um... Some dodgy stuff written in that article, IMO!

"Fossilised tree"? So why does it appear to be made of wood? Carbon dating? So, made of carbon, i.e. wood! Was it the Neaderthals who cut it down with their chain saws then? :)

I see from the comments (ignoring the usual nuts) some readers picked up on this. Trouble is, what else was written here by somebody who didn't really understand what they were writing about? It would be interesting to know what the true facts are.


PS. Then again, perhaps not! Fossilised does not mean petrified, so I guess it could be described as a "fossil" tree. :oops:


I prefer the Google definition of Fossil - the remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form., so it can include the impressions of dinosaur footprints, or the feeding burrows of worms (termed trace fossils). In this case I would assume the tree was toppled and entombed in some volcanic lava or ash deposit, which appears to have just scorched the outside. It still counts as a fossil even though it is not turned to rock. The use of the word petrified in that definition is used to make clear that soft animal and plant parts usually rot away. But they can be preserved such as where insects are trapped in amber (as in Jurassic Park).

AIUI carbon dating has been extended with reasonable reliability back to 55.000 years BP, so at 42,000 I assume the tree has a carbon date. There may also be a radiometric date using something like U-Th from the surrounding volcanics as well.

ursaminortaur
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Re: Magnetic field reversal

#391014

Postby ursaminortaur » March 1st, 2021, 1:29 am

Nimrod103 wrote:
XFool wrote:
88V8 wrote:Interesting article about the earth's magnetic field... how it periodically reverses .... and the effect on climate and life on earth

https://newatlas.com/environment/ancien ... ent-chaos/

Um... Some dodgy stuff written in that article, IMO!

"Fossilised tree"? So why does it appear to be made of wood? Carbon dating? So, made of carbon, i.e. wood! Was it the Neaderthals who cut it down with their chain saws then? :)

I see from the comments (ignoring the usual nuts) some readers picked up on this. Trouble is, what else was written here by somebody who didn't really understand what they were writing about? It would be interesting to know what the true facts are.


PS. Then again, perhaps not! Fossilised does not mean petrified, so I guess it could be described as a "fossil" tree. :oops:


I prefer the Google definition of Fossil - the remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form., so it can include the impressions of dinosaur footprints, or the feeding burrows of worms (termed trace fossils). In this case I would assume the tree was toppled and entombed in some volcanic lava or ash deposit, which appears to have just scorched the outside. It still counts as a fossil even though it is not turned to rock. The use of the word petrified in that definition is used to make clear that soft animal and plant parts usually rot away. But they can be preserved such as where insects are trapped in amber (as in Jurassic Park).

AIUI carbon dating has been extended with reasonable reliability back to 55.000 years BP, so at 42,000 I assume the tree has a carbon date. There may also be a radiometric date using something like U-Th from the surrounding volcanics as well.


Fully petrifying a tree trunk can take millions of years. Hence it shouldn't be surprising that in this case there is probably ample organic material left to allow carbon dating.

https://study.com/academy/answer/how-long-does-it-take-for-petrified-wood-to-form.html

It takes millions of years for petrified wood to form. The process begins when wood is buried quickly and deeply by water and mineral-rich sediment, removing it from a high-oxygen environment. This slows the process of decomposition nearly to a halt, letting the minerals in the water and sediment seep into the wood. Over time, the organic material gradually decays and the minerals are precipitated from the water, turning the wood to stone.

A limiting factor to the time it takes for this to occur is the time it takes for water infiltration into the fibrous structures of the buried wood as well as the particular minerals dissolved in the water. With this in mind, the most we can say is that the mineralization process can take millions of years.


https://www.bbc.com/future/article/20180215-how-does-fossilisation-happen

Now we come to the thorny technicality of what a fossil actually is – and what kind of fossil you want your body to be.

Very generally, anything up to around 50,000 years old is what’s known as a ‘subfossil’. These are largely still made up of the original tissues of the organism. Extinct Pleistocene megafauna found in caves – such as giant ground sloths in South America, cave bears in Europe, and marsupial lions in Australia – are good examples.

However, if you want your remains to become a fossil that lasts for millions of years, then you really want minerals to seep through your bones and replace them with harder substances. This process, known as ‘permineralisation’, is what typically creates a fully-fledged fossil. It can take millions of years.


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