The Earth’s Wobbly Rotation – Some Modern Internet Contributions

When in the 1980’s I began to investigate the Earth’s rotation as a likely cause of catastrophism in prehistory the information available was scant and highly confusing. There was no internet. Books and papers had to be sought and photocopied in libraries and these allowed me to do my own calculations and graphs, using spreadsheets. Computers in the 1980’s were DOS-based with dual floppy-disks and not much memory! The spreadsheets and data would not convert to the newer ‘Windows’ computers and I was not prepared to repeat the work. The primitive sine-wave graphs that I made were intended to illustrate how a Chandler Wobble of greater amplitude could interfere with the annual seasons to cause seven-year rhythms in the climate. These were the basis of the theories in my Book: The Atlantis Researches – the Earth’s Rotation in Mythology and Prehistory. This was republished in 2002 as Atlantis of the West. However it remained at its heart a book about the ancient variations in the Earth’s Rotation – although that went over the heads of the publisher and of many readers who simply wanted a book about Atlantis!

The motions of the rotation axis today (the transient wobbles) are tiny – just a few metres on the ground – but if excited by an event to a greater amplitude than the crustal earthquakes of today, they could explain most of the catastrophic phenomena that we find in ancient myths and legends. Here, for example, is my original plot from The Atlantis Researches, illustrating how a transient wobble of a few degrees of latitude could explain the seven-year famine of the Biblical Joseph.

Seven-year rhythms(2).jpg
Seven-year spiral(2)_edited.jpg

Reproducing Joseph's Famine

The interference of a transient wobble of period 13 months with the annual seasons; amplitude exaggerated for illustration purposes only. The wobble would make approximately six circuits of the pole every seven years, causing alternating enhanced and suppressed seasons. Since the transient motion decays exponentially over 20 years the third circuit is negligible, thus potentially explaining the seven ‘good’ years followed by seven ‘bad years’. Of course it is not that simple! Geophysicists would have to explain the combination of wobbles and nutations that could cause such a climatic rhythm and what could trigger it.


These diagrams were originally figs 10.3 & 10.4 from Chapter 10 of Atlantis of the West.

In the 1980’s the terminology used by specialist geophysicists was still imprecise and the available research heavy with mathematics. There was no easy entry point for the general researcher. At that time the Chandler wobble was routinely monitored as was its small effect on the modern rotation and the geographical displacement of the poles. The other solution to the equations: the accompanying nearly-diurnal free wobble, was a curiosity too small to be observed. Only since it was realised that the NDFW must occur on top of a much larger nutation in space, the free core nutation (which had always been in the physics but largely overlooked) has there been progress in understanding the period and lifetime of these transient motions. It is apparent that the physicists understood their equations, but not necessarily how a real Earth would actually behave. That geophysicists could neglect a motion so large as the core nutation for over a century was somewhat of an embarrassment; it didn’t even have a recognised name! It rather reminded me of the forgotten ‘Mexican Klingons’ on Star Trek – they don’t like to talk about it! *

Today, one may find numerous excellent research graphics and animations on the internet to illustrate the Chandler Wobble and the other motions for the benefit of the baffled general reader, who just wants to know what all the complex maths and jargon actually means. Here are just a few links that illustrate the motions pictorially far better than I could ever describe them.


A simple illustrated intro to the wobble of the axis

Chandler Wobble: Why Earth Wobbles Like a Toy Top - Earth How


A more detailed and illustrated educational seminar explaining the Earth’s motions

Introduction to Earth Sciences I (


An animation of the wandering pole based on modern measurements as it hunts to find the stable pole of figure.

Polar Motion Animation 1973-2012 - YouTube


An analysis of the Chandler Wobble covering the period 2005-6 highlighting an anomaly

Chandler Wobble of Earth has Major Anomaly (


A plot of the spiralling of the poles since the earliest observations

The Wandering Path of Chandler's Wobble - Circular Plots from 1890--2001 by MWM which show that the average location of the pole is shifting at an accelerating rate (


Two published papers that establish the period of the Core Nutation at 430-432 days

Parameters of the Earth’s Free Core Nutation from Diurnal Strain Tides | Scientific Reports (


Detection of free core nutation resonance variation in Earth tide from global superconducting gravimeter observations | Earth, Planets and Space | Full Text (


Or you can do your own Google search and find new ones

chandler wobble animation - Google Search


Relevant Hyperlinks:


* See "Trials and Tribble-ations", Star Trek: Deep Space Nine: Season 5; Episode 6


This page is a work-in-progress and more links may be recommended as they are discovered.

Citation: Dunbavin, Paul (2022) The Earth’s Wobbly Rotation – Some Modern Internet Contributions ;


Tags: Chandler wobble, free core nutation, FCN, nearly diurnal wobble, NDFW, pole shift, Joseph’s famine

Copyright: Paul Dunbavin & Third Millennium Publishing, V 1.1 February 2022