The force generating the magnetic field shielding us from deadly solar winds has a fascinating life of its own, and one definitely worth exploring more closely if humanity is to get a fundamental understanding of the planet we call home, according to veteran Russian geophysicist, geoinformatics expert and Schmidt Institute of Physics of the Earth head researcher Anatoly Solovyov.
“The task of geoinformatics is to develop mathematical tools capable of handling the immense quantities of information that we began receiving recently thanks to modern networks digitally recording various natural process,” Dr. Solovyov explained.
“The ability to obtain new knowledge by processing large, often heterogeneous data from different disciplines in the field of Earth sciences, be it geomagnetism, gravity field anomalies, seismological observations, tsunamis,” and other phenomena, including the study of rapid fluctuations in Earth’s magnetic field has become possible only with modern technology and computing power, the academic said.
“Until recently, the characteristic temporal variations in the magnetic field were subject to study measured in centuries, with magnetic field reversals measured in the hundreds of thousands of years. With the advent of modern magnetic field recording systems, rapid variations in the magnetic field have been detected on characteristic time scales of one to ten years,” Solovyev noted. “We’ve learned to record such changes in the magnetic field – caused mainly by processes occurring at the boundary of the Earth’s liquid core, the mantle. We can observer them on the surface of Earth and from near-Earth space using high-precision geomagnetic observatories and low-orbit satellite systems.”
Dr. Anatoly Alexandrovich Solovyev, geophysicist, specialist in geoinformatics, doctor of physical and mathematical sciences, corresponding member and professor with the Russian Academy of Sciences.
© Sputnik / Olga Merzlyakova
Earth Geomagnetic Poles’ Past…and Future
Solovyev, coauthor of the Atlas of the Earth’s Magnetic Field, a comprehensive 2012 study of the evolution of Earth’s magnetic field from the years 1500 to 2010, and a top scholar involved in the creation of geomagnetic monitoring centers, says these observatories provide scientists the ability to study the temporal variability of Earths’ magnetic field over long periods of time.
“Modern models allow us to reconstruct the magnetic field not only of the past 500 years, but over tens of thousands of years, based on paleomagnetic and archeomagnetic data. We can say that, for example, that the movement of the North Magnetic Pole has significantly accelerated recently, and there is speculation that an inversion can be expected in the near future,” the academic explained.
Of course, there are counterarguments to the pole flip thesis, Solovyev noted.
“For example, 40,000 years ago, the Laschamp event geomagnetic excursion occurred when the dipole axis deviated significantly from the rotation axis. Thus, the North Magnetic Pole can shift to angles of 30-40 degrees, with this process accompanied by a major weakening of the magnetic field. 40,000 years ago, it weakened several times over compared to its present intensity. Nevertheless, everything later returned to its normal place.”
“On the scale we’re talking about, this is related to processes occurring in the liquid core. These have not been fully studied yet, because we only have indirect data. There’s actually very little data. Modern field observation systems were introduced only in the late 1980s, when digital data recordings became possible. Vector-based measurements using low-earth orbit satellites began to be conducted systematically only in the late 1990s, so a thorough reconstruction of the processes occurring in the liquid core, especially over such large intervals, is only possible using theoretical approximations,” Dr. Solovyev explained.
On top of that, it’s an issue of computing power, according to the academic. “For example, one of the latest achievements in the field of numerical modeling of such processes was the possibility to recreate variations associated with rapid changes to the magnetic field – so-called geomagnetic jerks, something achieved only in the last 50 years.”
Scientists have some idea about how the redistribution of magnetic flux occurs at the boundary of the liquid core and mantle, and theoretical concepts explaining the recent acceleration of the movement of the North Magnetic Pole in Russia’s direction, Solovyev said.
Life-Giving Force Shielding the Earth
As for the creation of Earth’s magnetic field itself, scientists postulate that the heterogeneity of states in the Earth’s mantle led to the non-stationary processes that generate the magnetic field.
“They are affected, in particular, by the Coriolis force, thermal convection, compositional convection. Such heterogeneities in Earth’s depths have apparently given rise to process of the creation of the geodynamo and its consequent maintenance,” Solovyev noted, referring to the theory about the mechanisms through which celestial bodies, including Earth, generate their magnetic fields.
“Geophysics is largely a science dedicated to heterogeneities and anomalies, starting with the fact that our planet consists of core-shells that are heterogeneous both in their composition and state of aggregation…In order to start up the dynamo in the form we see today, there must be a solid and a liquid core. The dynamo’s operating modes change depending on the radio of radii of the inner and outer cores. As the inner core grows, the dynamo’s operating modes (inversion frequency and intensity) also change,” the academic said.
In turn, the magnetic sphere contributed to the formation of life on Earth, given its role shielding us from the deadly effects of solar radiation.
At the same time, powerful magnetic storms can have an indirect impact on human health, with the dense flow of high-speed solar winds affecting the magnetosphere, in turn affecting atmospheric pressure, blood pressure, hormonal background, and various environmental factors.
Then, there is solar radiation. “At high altitudes, where high-energy particles penetrate close to the Earth’s surface and can reach the altitude of commercial aviation, the influence of precisely this radiation plan can be felt. Therefore, the [Russian] Space Weather Prediction Center provides a forecast for the level of geomagnetic activity on the Earth’s surface, including for the benefit of aviation. The trajectory of transpolar flights is adjusted accordingly depending on space weather. After all, in a powerful magnetic storm, a human being at such an altitude could receive a dose of radiation in one hour comparable to the average annual dose of radiation,” Solovyev noted.
Humans Adopt to Survive
Humanity has evolved by adapting to the natural changes in our geomagnetic environment over past millennia, and Dr. Solovyev is confident the species can adapt to abrupt changes in the magnetic field, should they take place once again.
“[Such changes] will not happen instantly. On a geological scale, it’s an instant, but on the scale we’re accustomed to, it’s quite a significant period of time, amounting to thousands of years, with the duration of the inversion itself lasting several thousand years…The magnetic field will gradually weaken. We have no documentary evidence about what will accompany this. Perhaps our species will be preserved, because the ionosphere and atmosphere will remain. Currents will be generated in the ionosphere, acting as a kind of shield in relation to those harmful particles flying toward us from the Sun, and may well protect us from solar radiation.”
Flips in the geomagnetic poles occur an average of 500,000 years or so, with the last one taking place about 750,000 years ago.
“No one knows when to expect the next one. It does not happen regularly. Moreover, periods know as superchrons were discovered when no inversion would occur for millions of years, with the field maintaining some fixed polarity. We know of three such superchrons,” Solovyev pointed out.
With homo erectus dating back about two million years, and the last inversion taking place three quarters of a million years ago, that means that the last time a pole flip occurred, it didn’t wipe out our ancestors.
More Data Can Lead to Fundamental Discoveries
Solovyev and his colleagues worked to build the Rotkovets Geobiosphere station in Popovka, Arkhangelsk region in 2012, providing researchers with pristine data free of electromagnetic interference and allowing for a range of geophysical observations.
“Since I have a background in engineering education, although it is a mathematical one, I would like to significantly expand the network of magnetic field observations using observatories of the highest class. This would make it possible to study the subtle effects in the change of the Earth’s magnetic field over a long-term basis,” Solovyev stressed.
With this knowledge, humanity would gain “information about the structure and arrangement of our planet. This is undoubtedly of fundamental importance,” he added.
“We will be able, for example, to study in greater detail the movement of the Magnetic North Pole, around which all the most intense changes in the magnetic field occur and, as a result, the most negative effects of space weather are observed. We’ll be able to adjust the trajectories of aircraft, be prepared for the impact of solar radiation on satellite systems. It’s a wide range of problems, from purely theoretical to important applied aspects,” Dr. Solovyev summed up.