Geomagnetic jerks seem to produce changes to physical properties of planet Earth. Changing geomagnetic properties and other measured things such as the rotational spin rate of our planet.
A large geomagnetic jerk not only changes Earth's magnetic field it also changes the length of the Earth's day.
Periodic wobbles in Earth's core change the length of a day every 5.9 years, according to a study published in the journal Nature.
Teasing out this subtle cycle, which subtracts and adds mere milliseconds to each day, also revealed a match between abrupt changes in the length of day and Earth's magnetic field. During these short-lived lurches in the magnetic field intensity, events called geomagnetic jerks, Earth's day also shifts by 0.1 millisecond, the researchers report. Since 1969, scientists have detected 10 geomagnetic jerks lasting less than a year.
... "I have no clue," said Holme, lead study author and a geophysicist at the University of Liverpool in the U.K. "Something is happening at the core-mantle boundary, because you're seeing the geomagnetic and the rotational effect at the same time, but we don't know what's going on,"
Earth's 6-Year Twitch Changes Day Length | Live Science
Would massive electromagnetic geomagnetic jerks help explain temporary changes in the Earths days and rotations as suggested by Immanuel Velikovsky, Peter Warlow in his The Reversing Earth book and many other authors and investigators of plasma mythology, Saturn Model and the Electric Universe theory? Or are they just strange multiple local phenomena?
What is a geomagnetic jerk?
The term "geomagnetic jerk” commonly denotes an abrupt change in the slope of secular variation of any of the elements of the geomagnetic field. Geomagnetic jerks occur on a time scale of the order of 1 year and it is observable in the secular variations of many worldwide observatories. In the last century many events have occurred, some involving observatories on global scale others on regional scale.
Geomagnetic jerks | Istituto Nazionale di Geofisica e Vulcanologia
In geophysics, a geomagnetic jerk or secular geomagnetic variation impulse is a relatively sudden change in the second derivative of the Earth's magnetic field with respect to time.
... The name "jerk" was borrowed from dynamics, where it means the rate of change of the acceleration of a body, that is, the third derivative of its position with respect to time (the acceleration being the second derivative); or, more specifically, a sudden and momentary spike (or dip) in that rate.
Jerks seem to occur in irregular intervals, in the average about once every 10 years. In the period between jerks, each component of the field at a specific location changes with time t approximately as a fixed polynomial of the second degree, A t2 + B t + C. Each jerk is a relatively sudden change (spread over a period of a few months to a couple of years) in the A coefficient of this formula, which determines the second derivative; and usually in B and C coefficients as well.
Geomagnetic jerk | Wikipedia
Geomagnetic jerks (Change to Magnetic Dipole) : Electromagnetism is the interaction responsible for practically all the phenomena encountered in our daily life. Electromagnetism manifests as both electrical fields and magnetic fields. Both fields are simply different aspects of electromagnetism, and hence are fundamentally related. Thus, a changing electrical field generates a magnetic field and conversely, a changing magnetic field generates an electric field.The earth's core, through which its direct rotating current generates the magnetic field that we detect at the surface, does not keep pace with the outer “surface” crust. Geo-physicists acknowledge that the magnetic field has a mainly dipole structure that changes over time and moves in a significant westward drift of about one meter per hour.
Geomagnetic Jerk | Ascension Glossary
Why are geomagnetic jerks different in different locations?
The first jerk was identified at the end of the 70’s. Since then, using different techniques, 8 more have been identified respectively in the years: 1901, 1913, 1925, 1932, 1949, 1969, 1978 and 1991. The secular variation (SV) of the Y component of the geomagnetic field as a function of time, from two different observatories, is shown in the figure. The SV trend clearly shows the presence of rapid inclination changes, thus of jerks, during the last century. Two more events are shown in the figure, (1938 and 1958) but not everyone identifies them as jerks.
Definition - Geomagnetic Jerks | Istituto Nazionale di Geofisica e Vulcanologia
The strength of each jerk varies from location to location, and some jerks are observed only in some regions. For example, the 1949 jerk was clearly observed at Tucson (North America, long. 249.17°), but not at Chambon la Forêt (Europe, long. 2.27°). Moreover, the global jerks seem to occur at slightly different times in different regions; often earlier in the Northern hemisphere than in the Southern hemisphere.
Geomagnetic jerk | Wikipedia
What processes create geomagnetic jerks?
Currently we think that the jerk origin is to be researched in the inside of the Earth, although somebody argue of this hypothesis claiming jerks have an external origin probably linked to the effects that are induced by the solar cycle. The verification of the possibility of the internal origin of the jerk, is surely an important starting point for the study of the dynamic of the Earth interior and in particular for the study of the conductivity properties of the mantle. In fact, if such a signal would really be of internal origin, this would set some very precise limits on the mantle conductivity (through which this phenomenon propagates). On the basis of the jerk impulsive characteristics, a conductivity value for all the mantle of about 300 (Wm)-1 was set. Such value is extremely lower with respect to the one that was estimated before the discovery of the jerk but it would find a confirm in the electric potential measures made on transatlantic cables.
Why do we study the geomagnetic Jerks? - Geomagnetic Jerks | INGV
Geomagnetic jerks, which in the second half of the twentieth century occurred in 1969, 1978, 1991 and 1999, are abrupt changes in the second time-derivative (secular acceleration) of the Earth's magnetic field. Jerks separate periods of almost steady secular acceleration, so that the first time-derivative (secular variation) appears as a series of straight-line segments separated by geomagnetic jerks. The fact that they represent a reorganization of the secular variation implies that they are of internal origin (as has been established through spherical harmonic analysis), and their short timescale implies that they are due to a change in the fluid flow at the surface of the Earth's core (as has also been established through mapping the time-varying flow at the core surface). However, little is understood of their physical origin. Here we show that geomagnetic jerks can be explained by the combination of a steady flow and a simple time-varying, axisymmetric, equatorially symmetric, toroidal zonal flow. Such a flow is consistent with torsional oscillations in the Earth's core, which are simple oscillatory flows in the core that are expected on theoretical grounds9, and observed in both core flow models10 and numerical dynamo models.
The origin of geomagnetic jerks | Nature