posted on Feb, 6 2012 @ 03:59 PM
Another reason for these sounds that wasn't included, is the reversal of the magnetic field, (magnetic flip)
I remember watching a documentary on this several years ago, (have tried to find it but no luck yet). The professor, had made a computer simulation
screensaver of the earth & its magnetic field.
He then had to go away for a period, but upon his return ,found the poles had flipped in the computer simulation.
Our magnetic field has been decreasing , suggesting that it may be in the early stages of a flip (this can take a couple of thousand years).
At present, the overall geomagnetic field is becoming weaker; the present strong deterioration corresponds to a 10–15% decline over the last 150
years and has accelerated in the past several years; geomagnetic intensity has declined almost continuously from a maximum 35% above the modern value
achieved approximately 2,000 years ago. The rate of decrease and the current strength are within the normal range of variation, as shown by the record
of past magnetic fields recorded in rocks (figure on right). The nature of Earth's magnetic field is one of heteroscedastic fluctuation. An
instantaneous measurement of it, or several measurements of it across the span of decades or centuries, are not sufficient to extrapolate an overall
trend in the field strength. It has gone up and down in the past for no apparent reason. Also, noting the local intensity of the dipole field (or its
fluctuation) is insufficient to characterize Earth's magnetic field as a whole, as it is not strictly a dipole field. The dipole component of
Earth's field can diminish even while the total magnetic field remains the same or increases. The Earth's magnetic north pole is drifting from
northern Canada towards Siberia with a presently accelerating rate—10 km per year at the beginning of the 20th century, up to 40 km per year in
2003, and since then has only accelerated. In the last decade magnetic north was shifting roughly one degree every five years.
I think that the sounds may have something to do with the changes taking place ,not only at the earths core but also in the crust. The sounds of this
,I think, would reverberate into the ionosphere producing the familiar, "Where is it coming from??" question by hearers.