Geomagnetic Field Reversal

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Discussion Overview

The discussion centers around geomagnetic field reversals (GFR), specifically the implications of these events on Earth's history and life forms, as well as the timing and frequency of such reversals. Participants explore historical data, current beliefs in the scientific community, and the relationship between magnetic reversals and significant biological or geological events.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the current scientific consensus regarding the impact of geomagnetic field reversals on significant events in world history, such as the emergence of humans and the extinction of certain species.
  • One participant asserts that humanoid life has not been influenced by the last magnetic reversal, though they do not provide a source for this claim.
  • Another participant mentions that statistically, we may be overdue for another reversal, referencing a geology lecture but not providing specific sources.
  • Discussion includes the last known reversal occurring approximately 780,000 years ago, with references to the Brunhes Normal Chron and the preceding Matuyama Reverse Chron.
  • There is mention of at least 12 magnetic reversals in the last 4 million years, with some participants noting the existence of super-chrons lasting tens of millions of years, suggesting that statistical predictions may be unreliable.
  • One participant raises a mild dispute regarding the relationship between geomagnetic excursions and climate changes or cosmogenic radioactivity, citing conflicting sources.

Areas of Agreement / Disagreement

Participants express differing views on the implications of geomagnetic reversals for life on Earth and the reliability of statistical predictions regarding future reversals. The discussion remains unresolved regarding the impact of these events on historical biological changes.

Contextual Notes

Participants reference various geological timeframes and chronologies, but there are limitations in the clarity of definitions and the sources cited. Some claims are made without supporting evidence, and the discussion includes unresolved questions about the relationship between geomagnetic events and climate or biological changes.

Lacy33
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Without pulling out the paper I wrote 10 some years ago discussing the geomagnetic field reversal, I would like to know what current data analysis agrees on about the following:
From journals, Nature and Science back as many years ago, I found the science community speculating that at the time of a reversal, GFR, things on the planet changed, such as the emergence of man, the disappearance of certain creatures.
In other words significant events in world history.
Is this still a belief of leading researchers?

Thank you,
Suzanne Elizabeth Seitz

Also posted in Astronomy & Cosmology section.
 
Last edited:
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Ive looked this up and no link seems to exist.

Humanoid life has not been influenced by the last mafnetic reversal for as far as is presently known.
 
Nerro said:
Ive looked this up and no link seems to exist.

Humanoid life has not been influenced by the last mafnetic reversal for as far as is presently known.


Thank you.

Since you looked it up, when was the last GFR?
And did it say when we are due for another?
Please.

S
 
I think statistically we are overdue for another reversal, but I'm not sure about this. I don't have a link though, I remember my geology lecturer presenting some data when I was studying this 6 months ago.

The last field reversal was 780,000 years ago, beginning the Brunhes Normal Chron. That was preceeded by the Matuyama Reverse Chron which began 2.5million years ago. There have been at least 12 magnetic reversals in the last 4 million years, as each chron (a period where the magnetic field is predominantely in one direction) is interspersed with short periods of the opposite field direction. From memory the Matuyama Chron had 3 or 4 of these, but we haven't had one during the Brunhes.
 
Considering that there have been super-chrons of tens of millions years, statistics have no meaning I'd say. To be more precieze the last chrons are: Brunhes -0.789 Mya- Matuyama - 2.581 Mya - Gauss - 3.58 Mya - Gilbert

Although Brunhes has no subchrons, there have been many more geomagnetic excursions, a collapse of the magnetic field, hardly known of the orther chrons, There is mild dispute whether those excursions are related to ice age climate and or cosmogenic radioactivity.

http://gsa.confex.com/gsa/inqu/finalprogram/abstract_54960.htm says yes,
but this one says no.
 
Thank you to all.

This has been very valuble to me and am already making my way back into this area if investigation.

S
 

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