Earth's magnetic field -- How "suddenly" does it switch?

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Discussion Overview

The discussion revolves around the timing and nature of Earth's magnetic field reversals, specifically addressing how "suddenly" these switches occur in geological terms. Participants explore the duration of these reversals, ranging from days to centuries, and consider recent research on the topic.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant notes that "suddenly" is a relative term and questions the actual time frame for magnetic field reversals, suggesting it could range from days to centuries.
  • Another participant mentions that some research indicates magnetic reversals may take several centuries to thousands of years, and points out that the reversal process might already be underway, referencing the South Atlantic Anomaly.
  • A link is provided to support the claim about the South Atlantic Anomaly, which is presented as relevant evidence in the discussion.
  • A further contribution cites research suggesting that geomagnetic reversals could include brief episodes of rapid field change, with one study indicating changes of six degrees per day during certain episodes, although it emphasizes that this does not imply reversals occur significantly faster than previously thought.
  • Participants note the age of the research being discussed, indicating it is over two decades old.

Areas of Agreement / Disagreement

Participants express differing views on the duration and nature of magnetic field reversals, with no consensus reached on the specifics of how quickly these changes can occur.

Contextual Notes

Some claims depend on interpretations of geological data and definitions of "suddenly," and there are unresolved aspects regarding the implications of rapid changes during reversals.

zuz
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I know, geologicaly speaking, that "suddenly" is a relative term. So when they say that Earths magnetic field suddenly switches, how long are we talking about. Days, hours, centuries?
 
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Several centuries to thousands years actually. Some researches believe the magnetic reversal is already in progress now (see South Atlantic Anomaly)
 
https://www.researchgate.net/profile/Pierre_Camps/publication/236622936_New_evidence_for_extraordinary_rapid_change_of_the_geomagnetic_field_during_a_reversal/links/00b7d518788b1d7062000000/New-evidence-for-extraordinary-rapid-change-of-the-geomagnetic-field-during-a-reversal.pdf discusses the possibility of rapid changes.
From the abstract: "Palaeomagnetic results from lava flows recording a geomagnetic polarity reversal at Steens Mountain, Oregon suggest the occurrence of brief episodes of astonishingly rapid field change of six degrees per day." (Emphasis mine.)
From the conclusions: "This is not to suppose that geomagnetic reversals take place much more quickly than the several thousand years currently supposed, but rather to suggest that polarity transitions may be punctuated by episodes of extraordinarily rapid field change."

(Please note the research is over two decades old.)
 
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