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North wasn't always North. It was South once.
Thread about Earth's fickle magnetic poles, their constant shift & eventual reversal !! And how old terracotta pots hold magnetic secrets.
Earth's magnetic north pole pointed by compass is far from true North Pole.
1/n https://twitter.com/OnlyNakedTruth/status/1264040617828429825
North wasn't always North. It was South once.
Thread about Earth's fickle magnetic poles, their constant shift & eventual reversal !! And how old terracotta pots hold magnetic secrets.
Earth's magnetic north pole pointed by compass is far from true North Pole.
1/n https://twitter.com/OnlyNakedTruth/status/1264040617828429825
If that isn't bizzare enough, the magnetic North pole KEEPS ON MOVING!!!
From Canada to mid Arctic Sea, it has moved by as much as 60 km a year.
2/n
From Canada to mid Arctic Sea, it has moved by as much as 60 km a year.
2/n
It is now expected to move further towards Russia in near future.... No , not all things can be blamed on Putin. And worse, it has accelerated significantly in last 10 years. 3/n
The strange thing is that while the south magnetic pole is also moving, it isn't moving as fast as North Pole. 4/n
To keep track, US and UK govt release a "World Magnetic Model" every five years as pole movement significantly impacts navigation, satellites etc
They HAD to release an out of cycle model because the movement of poles had accelerated!!! 5/n http://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release
They HAD to release an out of cycle model because the movement of poles had accelerated!!! 5/n http://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release
And now tighten your seat belts folks, because I am about to tell you about FLIPPING of magnetic poles.... Yes , where North becomes South and South becomes North.... 6/n
It DOES keeps on happening ! https://www.nationalgeographic.com/news/2018/02/earth-magnetic-field-flip-poles-spinning-magnet-alanna-mitchell/
It DOES keeps on happening ! https://www.nationalgeographic.com/news/2018/02/earth-magnetic-field-flip-poles-spinning-magnet-alanna-mitchell/
The last Pole reversal happened 780,000 years ago...
It is believed to be preceeded by a significant weakening of magnetic field in southern hemisphere - South Atlantic Anomaly. 7/n
It is believed to be preceeded by a significant weakening of magnetic field in southern hemisphere - South Atlantic Anomaly. 7/n
Between South America and Africa, Earth's magnetic field is weak. And this "anomaly" is weakening faster than previously thought. It is often the first precursor to a magnetic pole flip.
It exposes us to higher radiation from space which is shielded off by magnetic field. 8/n
It exposes us to higher radiation from space which is shielded off by magnetic field. 8/n
This image shows how Earth looks like during a pole reversal.
It is chaos of course!! But hold on, how do scientists know what happened to earth's magnetic field in the past. 9/n
It is chaos of course!! But hold on, how do scientists know what happened to earth's magnetic field in the past. 9/n
Ancient terracota wares found in Jerusalem contain particles of iron and other minerals that locked the info about intensity of magnetic fields at the time they were baked in kilns.
Thus providing historical info to scientists about earth's magnetism https://www.sciencealert.com/scientists-are-learning-more-about-earth-s-magnetic-field-from-ancient-stone-jars
Thus providing historical info to scientists about earth's magnetism https://www.sciencealert.com/scientists-are-learning-more-about-earth-s-magnetic-field-from-ancient-stone-jars
Similar data was collected by scientists from African villages that were burnt ritualistically hundreds of years ago.
Their clay pots recorded the earth's magnetic info at the time of burning. 11/n https://www.nationalgeographic.com/news/2018/03/earth-magnetic-field-south-atlantic-anomaly-africa-science/
Their clay pots recorded the earth's magnetic info at the time of burning. 11/n https://www.nationalgeographic.com/news/2018/03/earth-magnetic-field-south-atlantic-anomaly-africa-science/
Nobody knows when the next Pole reversal will happen. But we do know that intense changes in earth's magnetic field can expose us to harmful radiations, knock off global navigation tools and disrupt migratory routes of birds and animals.
Nature does remains mysterious.
Nature does remains mysterious.
