Posted on 03/16/2021 8:56:34 AM PDT by SunkenCiv
By studying what was once an iron smelting site in Cambodia, archaeologists and earth scientists unveiled a sharp change in Earth’s geomagnetic field direction and strength that occurred about 10 centuries ago. The new data, published this week in the journal Proceedings of the National Academy of Sciences, marks the first archaeomagnetism records from southeastern Asia. The researchers believe it will fill gaps in scientists’ understanding of Earth’s past magnetism, illuminating how the planet’s protective sheath may change in the future...
Tauxe worked with Mitch Hendrickson, an archaeologist at the University of Illinois at Chicago, who was excavating an iron-smelting site built by the Khmer Empire, which ruled Cambodia from the 9th century through the 14th centuries before collapsing. His team uncovered three iron furnaces at Tonle Bak, located in south-central Cambodia, which provided weapons and building material to fuel the Khmer Empire’s expansion beyond its capital of Angkor. Hendrickson’s team studied furnace fragments, slag waste left over from iron smelting, and tuyères, or air-delivery pipes.
When Tauxe and her team examined the iron waste, they found the Earth’s magnetic field moved suddenly westward and then eastward between 1200 and 1300. They also noticed a sharp decline in the field’s strength between 1100 and 1300.
(Excerpt) Read more at insidescience.org ...
Rebecca Boyle is an award-winning freelance journalist covering astronomy, zoonoses and everything in between. She is a contributing writer for The Atlantic and her work regularly appears in Popular Science, New Scientist, Aeon, Wired, and other publications for adults and kids. Follow her on twitter: @rboyle31.
No! It is fossil fuel burning causing shift in magnetic fields. Global warming has the same cause. Coming ice age will also be caused by too many cars & airplanes. /S
Has the “ climate change “ crowd come up with a way to control the magnetic field ?
Is young Greta Thunberg on the case ?
I almost lost an eye from flying pieces of toast! ;^)
Fred, they found your old ovens from a former life.
Do not give them your old recipes.
You mean the poles changed things out of Krakow?
You weren’t wearing dark sunglasses?..............
This technique is usually used on igneous rocks like basaltic lava flows that ‘lock in’ local magnetic fields when the magnetite goes through the curie temperature. An oriented core sample is taken with a diamond bit, then cut into pieces that are mounted in a special freely spinning gimbal mounted in three axis magnetometer. The sample is spun and an average magnetization vector is determined and worked back to the original sample orientation in space. Here they are doing it with furnace slag.
Hmmm ... 1100 to 1300 ... roughly coinciding with the latter half of Little Optimum (considered circa 950 to 1250).
So since the Glowball Warming that caused the warming preceded the drop in field strength while a gradual return to cooler weather was after or contemporary with it this is probably correlation and not causation (I’m assuming a weakening magnetic field would allow more energy to strike the whole earth, not less, whereas a strong field strength would shift some energy to the poles but block more of the solar wind otherwise).
If the field gets too weak we could always attach magnets to Founding Fathers spinning in their graves.
The second time I just sat in the back. I didn’t own a raincoat at that time. Or now.
Yes, the earth’s magnetic field changes with time. Anyone who has kept track of magnetic declination changes over the last few decades knows this. These data from about 1000 years ago are fascinating, though.
Yup. That’s the technique that provided the evidence for plate tectonics, still better known (and more accurately known) as continental drift. But it’s been used on pottery and such as well, the results providing consternation at times.
Yup, the compass adjustment for true north has changed just since I was a Boy Scout. The Scouts really tightened up membership after I was done with ‘em.
https://freerepublic.com/tag/poleshift/index
Magnetic shift? That gif sent my gyros tumbling.
OR, that lazy jerk Fred dumped a pile of hematite next to the furnace and never shoveled it in, which happened to be full of loadstone unbeknownst to anyone at the time.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
