Posted on 04/06/2015 5:26:46 AM PDT by ckilmer
October 17, 2012 in Geology & Climate
During the last ice age, around 41,000 years ago, there was a very rapid and complete reversal of the Earth’s geomagnetic field, according to new research. There was already localized evidence of polarity reversals during this time, but with the new research, the theory that it was a global event is now strongly supported. And very interestingly, it is one that nearly coincided with the very fast, short-term climate variability of the last ice age and the largest volcanic eruption in the northern hemisphere during the last 100,000 years.
Magnetic studies using sediment cores taken from the Black Sea, done by the GFZ German Research Centre for Geosciences, have clearly shown that if you had a compass at the Black Sea during that time, it would have pointed towards the south, not the north.
But more importantly, new data gathered by the researchers when it’s combined with additional data from previous studies in the North Atlantic, the South Pacific, and Hawaii, strongly supports the theory that this polarity reversal was truly global.
What’s considered so remarkable about this reversal is the speed that it’s now thought to have occurred: “The field geometry of reversed polarity, with field lines pointing into the opposite direction when compared to today’s configuration, lasted for only about 440 years, and it was associated with a field strength that was only one quarter of today’s field,” explains Norbert Nowaczyk. “The actual polarity changes lasted only 250 years. In terms of geological time scales, that is very fast.”
The magnetic field at the time would have only had about 5% of the strength of the field today. This would have resulted in the Earth almost completely losing its protective shield, allowing hard cosmic rays to hit the surface, and greatly increasing radiation exposure.
“This is documented by peaks of radioactive beryllium (10Be) in ice cores from this time, recovered from the Greenland ice sheet. 10Be as well as radioactive carbon (14C) is caused by the collision of high-energy protons from space with atoms of the atmosphere.”
The polarity reversal observed in the magnetisation of Black Sea sediments isn’t new knowledge, though — it’s been known of for at least 45 years. First discovered in “the analysis of the magnetisation of several lava flows near the village Laschamp near Clermont-Ferrand in the Massif Central, which differed significantly from today’s direction of the geomagnetic field.” This geomagnetic feature has since then been called the Laschamp event.
That’s limited data though, representing only some specific point readings of the geomagnetic field during that time, so there had been debate about how to interpret it. When combined with all of the new data though, it creates a convincing image of “geomagnetic field variability at a high temporal resolution.”
The cores analyzed also provided insight into “numerous abrupt climate changes during the last ice age” that occurred at the same time — these climate changes had already been observed in ice cores taken from Greenland. “This ultimately allowed a high precision synchronisation of the two data records from the Black Sea and Greenland.”
“The largest volcanic eruption on the Northern hemisphere in the past 100,000 years, namely the eruption of the super volcano 39,400 years ago in the area of today’s Phlegraean Fields near Naples, Italy, is also documented within the studied sediments from the Black Sea.”
This volcanic eruption released about 350 cubic kilometers of ash, rock, and lava over all of the eastern Mediterranean, and parts of Russia and Asia.
All three of these global disasters; a rapid and complete reversal of the Earth’s magnetic field, the drastic short-term climate variability of the last ice age, and one of the largest volcanic eruptions in the last million years; have now been tied together and placed into a precise and connected chronological order.
The new research was just published in the journal Earth and Planetary Science Letters.
Source: Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences
ping
In other words, they were Italian.
> The magnetic field at the time would have only had about 5% of the strength of the field today. This would have resulted in the Earth almost completely losing its protective shield, allowing hard cosmic rays to hit the surface, and greatly increasing radiation exposure.
That sentence has so much hypothetical guesstimation how could anyone take the rest of what they’re saying with any credibility? It reeks of Gorian liberalism for profit.
The article does not mention how CO2 is to blame.......
Or Bush
If we couldn't, there wouldn't be any such thing as x-ray pictures for doctors.
It's amazing the gifts that God gave us, and the suffering those tools have gotten rid of.
/johnny
from the article: "This is documented by peaks of radioactive beryllium (10Be) in ice cores from this time, recovered from the Greenland ice sheet.
10Be as well as radioactive carbon (14C) is caused by the collision of high-energy protons from space with atoms of the atmosphere."
Science = evidence + logic
ping
Have they decided how many times it’s been reversed. Last theory I’d heard indicated twice. One reversal and one reverting back.
R2z
Cosmic rays, in turn, cause water molecules to clump-together, forming water droplets/clouds, reflecting more of the sun's energy away from the earth, causing it to cool.
This phenomenon can actually be reproduced in a laboratory with appropriate apparatus; it does not rely on unvalidated computer models.
How could that not be global?
You think so?
Too bad you missed out on the Grunt family reunions of a few years back!
Sadly the old ones are gone now.
All sons of Scotland. They could walk erect to get by, but among the clan, not so much.
Proud to say that I have a very nice ape index!
Or evil republicans who only want dirty air, dirty water and to kill our children...
I had heard that all gingers had Neanderthal blood. That would include myself and all my children. My great-grandfather was a true left handed red headed cowboy. It trickled down until all his great great grandchildren were red headed including my adopted daughter. The red headedness faded until now there is really only one who is clearly red headed at the age of 29.
> Science = evidence + logic
I’m not discounting or disputing the scientiic method. I was commenting on the essence of that one sentence which qppears to be constructed to further the liberal agenda...
It was necessary.
God saw that the birds would fly north for the summer, but it was covered in ice, so that hey would die.
So he said, “Let the pole of the magnets become as the opposite end.” and it was so.
Then the birds flew south for the summer and they were saved from a freezing death................
“eruption of the super volcano 39,400 years ago in the area of today’s Phlegraean Fields near Naples, Italy”
I thought Toba’ was the largest eruption?
Uhhh, I thought the last time the poles reversed was something like 780,000 years ago, not 40,000. Did I misread something somewhere?
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