The Earth's magnetic field, which protects the planet and guides many creatures living on it, apparently began to collapse 150 years ago. The strength of the field has so far weakened by 10 to 15 percent, and recently the rate of its decay has even increased, which has sparked discussion of a change heralded by a reversal in the lines of magnetic force that surrounds the Earth
Where will the compasses point?
16/07/04
The Earth's magnetic field, which protects the planet and guides many creatures living on it, apparently began to collapse 150 years ago. The strength of the field has so far weakened by 10 to 15 percent, and recently the rate of its decay has even increased, which has sparked discussion of a change heralded by a reversal in the lines of magnetic force that surrounds the Earth.
In the process of reversing a magnetic field, the field weakens until it almost disappears, then returns in reverse polarity. At the end of the process, compasses that now point north will point south. And in the millennia of transition when the field fades, many things on Earth will deviate from their natural course.
A reversal of the magnetic field lines could cause power lines to be disabled, harm astronauts and satellites, increase holes in the ozone layer, and confuse birds, fish and other animals that are guided by the Earth's magnetic field. Experts claim that the consequences of the phenomenon will not be catastrophic, despite some doomsday prophecies and dubious evidence linking the reversal of the field and the extinction of species.
Although a complete reversal of the field may take hundreds or thousands of years, the rapid weakening of the magnetic field is already harmful to satellites. Last month, the European Space Agency launched the largest project to detect changes in the magnetic field. A new trio of satellites, called "Swarm", will measure the collapse of the field more precisely than before, and will help scientists predict its consequences.
"We want to understand how it will develop in the future, just as people try to predict the weather," said Dr. Gauthier Hulot, a French geophysicist who works on the satellite program. "I am convinced that at the end of the mission we will be able to produce a first forecast."
New York Times
Pole reversal: the reversal between the north and the south of the Earth's magnetic field will last 7,000 years
The reversal of the Earth's magnetic field, a rare but difficult process from the perspective of life on Earth and especially human life, will be completed within 7,000 years, according to a new study.
The "reversal" between the north and south poles occurs at irregular intervals. The last reversal occurred 780 thousand years ago.
The 180-degree rotation occurs whenever there is a change in the lap patterns in the layer of molten iron floating around the outer edge of the Earth's core, and like a dynamo, the process creates the magnetic field. The strength of the magnetic field decreases slightly before the circulation rate returns and a new polarity appears.
But how long does this transition process take before the new poles are formed? Until now, scientists have only guessed. Estimates ranged from two thousand years to 28 thousand years.
American researcher Bradford Clement sheds light on this area of uncertainty by analyzing records taken from samples of geological strata excavated from a variety of sites on Earth.
These samples, classified into four separate eras in the Earth's history, contain the magnetic resonance of the magnetic field that prevailed at that time. These records reveal an average time of 7,000 years for the Earth to reverse the poles. Clement of Florida International University wrote in the journal Nature.
According to him this transition does not happen all at once. It happens faster at the equator and takes longer at high latitudes.
The reason for this, according to Clement, is that in the absence of the main magnetic field - in the north-south direction, the earth develops a secondary magnetic field in which many mini-poles exist. Finally the two main poles are formed again, but in the opposite directions of the planet, restoring their supremacy.
No one knows exactly what will happen to life on Earth during the reversal we are in the midst of, but some borderline estimates even speak of doomsday.
Many aspects of our daily lives will literally be turned upside down, both for humans - given our dependence on magnets for navigation as well as on migrating animals that use internal compasses. We will also be exposed to lethal doses of solar radiation, which we are normally protected from by the magnetic field. Loss of this shield could cause particles from the sun to collide with the upper atmosphere, heating it up and causing severe climate changes.
The concern began in 2002 after a French geophysicist named Gauthier Hulot discovered a weakness in the magnetic field near the poles, which may be interpreted as an early sign that a "reversal" is approaching.
The reversal appears to occur randomly over time, said Ronald Merrill, a scientist at the University of Washington. The short intervals were 20 thousand and 30 thousand years and the longest - 50 million years.
For information on the Spice.com website
8 תגובות
How about tens of thousands of years, if in 150 years we have already weakened between 10-15%???
Life, including birds and mammals in the sea and on land, survived the
the reverse more than once. So maybe you shouldn't exaggerate
in the expected difficulties due to the reversal.
Haim F / ASCII
Already 35 years ago, a spacecraft was placed at the point of equilibrium between us and the sun - the distance is "only" about one and a half million kilometers from us. But - this is not a point where a body can stand still and not move - this is not a point of dynamic equilibrium.
But - in order to affect the radiation from the sun, the ring would have to be enormous in size, thousands of kilometers in radius.
... not to mention at all the effect that will have on the earth as a result of the particles from the solar wind not reaching the earth.
(No, Haim P, the result will not be as you wish for it).
Chaim P
What size should the "ring" be?
And how do you transport it such a long distance?
(Of course, provided that the idea, so delusional, can even exist in the way you describe).
Suppose we place a ring (made of conductive material) between the sun and the earth at the equilibrium point of the gravitational forces of the sun and the sun. The ring is charged with an electric charge, accelerating it into a rotary motion. A magnetic field will be created which is a function of the charge multiplied by the rotation speed. We received a magnetic field that is indeed weaker than the Earth's, but placed at such a great distance that its effect (even a tiny one) on the solar radiation - will divert the particles from the Earth and beyond.
It may not be necessary to charge the ring because the solar radiation will already do this work.
All that remains is to take care of continuous rotation, and it doesn't seem too difficult to me even for today's technologies. (It seems to me that the ring has no energy consumption because it does not affect the energy of the particles passing through it)
I would be happy if they found proofreaders for the idea.
I agree with Yaron's question.
Admittedly, I have already asked this question several times, here on the site, a year or two ago, and I have not received an answer. Hopefully now there is a little more information on the subject.
Is there a connection between the weakening of the magnetic field and global warming?
Quote from the article: "Loss of this shield may result in particles from the sun colliding with the upper atmosphere, heating it and causing severe climate changes."
If the fields have indeed weakened by 10-15 percent in the last 150 years, can this even partially explain global warming?