The Hum, a consequence of human influence on space weather deduced from personal experience, the link with geomagnetic pulsation parameters.
Dr Barnes Homepage http://www.drchrisbarnes.co.uk
It has recently been shown that the Hum may be due to interaction between world power systems of different frequency standards. Power systems influence space weather so the question is posed can space weather predict the Hum? Subjective Hum levels on specific dates are compared with space weather reports from a reliable source and with spectra from the Kiruna induction magnetometer. Positive conclusions are drawn and the future use of such data for Hum prediction ought to be possible. Links with earthquake prediction are also highlighted.
The Hum is an electro-acoustic phenomenon known about since the 1970's and recently receiving much more press publicity and scientific credence. Those afflicted either physically hear or otherwise somehow perceive a characteristic sound. This was tone matched by some Hum hearers
Some cases of the Hum have been
shown to be due to simple low frequency noise pollution but others, indeed by
far the greater majority, have proved far more elusive. Any proper explanation
relevant to this majority of Hum cases must be able to account for the start up
of the phenomenon in the
In a geomagnetic storm, ground
induced currents can cause problems for power systems. These are usually longer
time period disturbances but can have time periods as low as 2 seconds6. Such
short periods are comparable with geomagnetic PC1 pulsations. So could PC1 pulsations have a direct effect
on power systems themselves? The
converse is almost certainly true. Human activity has been influencing PC1
pulsations for some time7 and8 where Fraser-Smith 1981
states the following; 'measurements have indicated that changes can also be
produced by moderately-powered pulsed HF radio (1–20 MHz), transmissions into
the ionosphere, high-powered pulsed VLF radio transmissions (3–15 kHz) into the
magnetosphere, and by the ULF magnetic noise (frequencies < 5 Hz) from
modern dc electric powered mass transit systems. Further, experiments reported
The present author's hypothesis is thus then that the human activity which gives rise to the Hum ought to be detectable as something unusual in the frequency spectra of PC1 pulsations. Secondly, conditions for PC1 pulsations are set by the solar wind speed and reflective in various geomagnetic parameters. Thus the next question to be posed is can the Hum or at least its increased likelihood be predicted from foregoing geomagnetic parameters?
Experiment and data sources
The experimental data has been available for several years and consists of private records of the author in which his personal experience of the Hum was logged, dates, times and relative amplitude or relative distress level. This data can be compared with data from induction magnetometers around the world and with geomagnetic data available at the spaceweather website9.
There are induction magnetometers in a number of locations round the world including HAARP at Gakona, Alaska10 and at Kiruna in Sweden11 to name but two. Unfortunately archive data seem to be no longer accessible at HAARP but Kiruna continues to prove very useful. The methodology used was simply to scrutinise the Kiruna spectrography at several times and dates when the Hum was experienced very badly at the author's residence and compare them with times when there was no Hum. With regards to geomagnetic parameters the average geomagnetic field (nT) and Kp values on these same 'Hum' and 'no Hum’ days was taken from http://www.spaceweather.com/.
Results and Discussion
With several years worth of available data there is the potential for a far more in depth, but horrendously time consuming, study here but in order to get these very important general trends released into the public domain as soon as possible the data sets were limited to a dozen strong Hum days taken at random from the years 2007, 2009 and 2011 and similarly for no Hum days.
The results of the geomagnetic parameters study are shown below:
With Hum- Average Solar Wind Speed 352 Km/sec
Without Hum – Average Solar Wind Speed 473 Km/sec
With Hum – Average field strength 4.3nT
Without Hum 3.09nT
The geomagnetic index Kp had an average value of 1.0 in each case.
The author is not a space physicist by training but an intuitive explanation of the result is offered.
Presumably slower moving protons and electrons are easier for power line harmonic radiation to interact with. Presumably as the Hum is manifest as a perturbation on a magnetic field the stronger the DC component the stronger the induced ground current.
The results of the induction magnetometer study are next shown by way of a few examples.
Figure 1 Kiruna induction magnetometer result for
In figure 1 the pulsations are in the form of random noise in two distinct broad bands. The lower band is centred on a bout .3Hz the upper on about 4 Hz. There is what looks like an anthropogenic signal or an earthquake shock precursor signal at about 1930 hours. There are less of these shock signals in figure 1 than in the other figures below and it is worth noting it was almost a month after this record that any significant world earthquakes took place. This record was however preceded by five significant world earthquakes earlier in April. The author has commented in the past about the Hum intensifying before earthquakes and diminishing soon afterwards. There is clearly an incredibly complex link here summed up by the work of Zotov and Gugliemi12. Others have commented too on changes in PC1 pulsations prior to earthquakes13.
Figure 2 Kiruna spectrum
In essence the background random
pulsations in figure 2 look very similar to those in figure 1 but in the Z -component there is lots more
evidence of anthropogenic signals at discrete
frequencies of 1.7,2,5 and 4 Hz . Other narrow time slot or short shock
wideband signal are also seen cutting across all three orthogonal filed
directions. The large
Figure 3 Kiruna 30th May 2007 Daytime Hum
Here the frequency of 1.7 Hz is
still present. There is a frequency of 2 Hz present in the X and Y directions
together with bursts of simultaneous comb spectra. There are a few earthquake shock precursors.
A magnitude 6.4 earthquake took place in
Figure 4 Kiruna
Here there are weak at 3-4 Hz in
all three directions and an almost continuous signal at about 17Hz in the X and
Y component. There are also earthquake shock pre-cursors. The
Figure 5 Kiruna 8th January 2011 Intense Hum
Here there is an almost continuous dash like signal at about .6 Hz in the Z component and weak bursts of signal at about 2 Hz in the X and Y components. There are also short shock earthquake pre-cursors. In that respect three significant earthquakes occurred around the world between January 9th and 19th 2011.
Figure 6 Intense Hum
Here the z direction has a
quasi-continuous signal at 1.7 Hz and weaker bursts at 3, 4 and 5 Hz. There are also a large amount of narrow time
broad frequency bursts and comb spectra bursts and earthquake shock pre-cursors
common to all three directions. In this respect a significant earthquake
In essence a significant range of features has been seen in figures 2-6 all of which would seem to be associated in some way with the Hum. The frequencies manifests in the PC1 pulsation band certainty seem to fit with anecdotally described modulation frequencies for the Hum. It is possible that the short bursts of frequencies as indicated by the dots and dash patterns in the spectra actually occur more often than recorded, the limitation being the response time of the equipment or that for part of the time they are lost in background noise. In this respect the HAARP magnetometer appears slightly more sensitive than the one at Kiruna. This can be seen by making a direct comparison as follows;
Figure 7 Kiruna magnetometer Man made influence seen as dashes approximately 0.6 Hz in Z -component
Figure 8 HAARP magnetometer
The same feature at 0.6 Hz can be seen but features at 1, 1.1, 2.2 and 3 Hz can also bee seen.
Due to the nature of ULF pulsation it will of course not be constant across all corners of the globe14.
From the author's personal experience the more complex the frequency pattern or the more pronounced the feature, the more intense the Hum as seemed. Generally speaking most of the times these type of features mainly appear in the Z- components but when they also appear in X or Y or both the Hum is even more intense.
Another question is how such a
richness of frequency component arises.
Due to the high non- linearity of the geomagnetic interaction itself
much sub-harmonic generation is possible so these frequencies could,
potentially all be higher order sub harmonics of 50 and 60 Hz or of the 10
Hz difference between them. It is not unreasonable to suggest this as a
possibility although no one else has commented directly upon it. For instance
the PC1 production process itself is known to be non-linear15 and
artificial PC1 pulsations have been produced at HAARP by employing ULF
modulation frequencies16, 17. Such ideas could also account for the
one time observation of the signal at 17 Hz, figure 4, which could conceivably
be the third sub-harmonic of the European power grid frequency or alternatively
be associated with railways18.
PC1 pulsation frequencies are not just influenced electromagnetically,
there has been shown to be an influence of acoustic signals as well19. Possibly thus earthbound infra sound
sources like wind turbines could influence the Hum. This would be another route
for them to perturb power systems via ground induced currents from space! Since when PLHR produces
As stated above, artificial PC1 signals in the 1-3 Hz range can be made be ionospheric heaters like HAARP16,17 and EISCAT21 but cannot usually be sustained for long periods. Since the Hum can last for extended periods of twelve hours or so and pre-dates ionopsheric heating the power grid hypothesis is more attractive.
Completing the story is how
humans perceive these modified PC1 pulsations. The author's view is they are
received as ground currents, which subsequently can re-interact and modulate existing power
system ground currents and frequencies (usually present due to phase imbalance)
and from there produce noise and vibration by electro-seismic coupling. Pc1
interactions are also proposed to directly affect the propagation and re-radiation
of PLHR to ground as
The observations made here won’t stop the Hum but at least they can help those afflicted predict to some extent periods of quiet or periods of quiet or periods of disturbance. The human entity is intimately attuned to mother earth whether we like it or not. Geomagnetic activity has shaped our past, even our politics and revolutions22 now modulated by mankind produces the Hum, who knows what is next?