Earth’s magnetic field plays a major role in protecting people from harmful radiation and geomagnetic activity that can affect satellite communications and power grid operations. And it moves.
Scientists have studied and tracked the movement of magnetic poles. for centuries. The historical movements of these poles are Global geometry changes The earth’s magnetic field. It could even mark the beginning of a reversal of the magnetic field, or a “reversal” between the north and south magnetic poles.
i am a physicist A person who studies the interactions between planets and space. A small shift in the North Magnetic Pole is no big deal, but a reversal could have a big impact on Earth’s climate and modern technology. But this reversal will not happen immediately.Instead, they occur for thousands of years.
Generation of magnetic field
So how is a magnetic field like the one around the Earth created?
Magnetic fields are generated by: moving charge.Substances that allow charge to move easily are called a conductor. Metal is an example of a conductor. People use metals to transfer electrical current from one place to another. The electric current itself is nothing more than negative charges called electrons moving through the metal.this current generates a magnetic field.
The layer of conductive material is Earth’s liquid iron core. A flow of charge moves throughout the core, and liquid iron also moves and circulates within the core. These movements create a magnetic field.
Earth isn’t the only planet with a magnetic field – gas giants like Jupiter have magnetic fields. conductive metal hydrogen layer That generates a magnetic field.
of Movement of these conductive layers Two types of fields occur within the planet. Larger motions, such as a large-scale rotation of a planet, cause a symmetrical magnetic field with a north and south pole, similar to a toy magnet.
These conductive layers may have local irregular movements due to the following reasons: local confusion or small-scale flows that do not follow large-scale patterns. These irregularities appear as small anomalies in the planet’s magnetic field or where the field deviates from a perfect dipole field.
These small-scale deviations in the magnetic field are actually bring about change Over time, large-scale magnetic fields can even reverse the polarity of the dipole completely, with north becoming south and vice versa. The “north” and “south” designations on a magnetic field refer to their opposite polarities. They have nothing to do with geographical north and south.
Earth’s magnetosphere, protective bubble
The Earth’s magnetic field creates magnetic “bubbles” called magnetic bubbles. magnetosphere Above the top layer of the atmosphere, ionospheric layer.
The magnetosphere plays a major role in protecting people. Protects and reflects harmful high energy. cosmic ray radiationThey are created by exploding stars and constantly move through space.The magnetosphere also interacts Solar winda stream of magnetized gas sent out by the Sun.
The interaction of the magnetosphere and ionosphere with the magnetized solar wind creates what scientists call. space weather. Solar winds are usually calm and space weather is rare.
However, sometimes the Sun releases large clouds of magnetic gas. coronal mass ejection To space. When these coronal mass ejections reach Earth, their interaction with the magnetosphere causes them to magnetic storm.magnetic storm can produce an aurorawhich occurs when a stream of energized particles hits the atmosphere and emits light.
During the space weather event, more dangerous radiation near the earth. This radiation is May cause damage to satellites And the astronauts. Space weather can also damage large-scale conducting systems, such as major pipelines and power grids, by overloading them. Current in these systems.
Space weather phenomena can also disrupt satellite communications. GPS operationmany people rely on.
field flip
Scientists map and track the entire shape and orientation Measuring the Earth’s magnetic field using local measurements of the field’s orientation and magnitude, and Recently, the model.
North magnetic pole position moved It has grown about 600 miles (965 kilometers) since it was first measured in 1831. Travel speeds have increased in recent years from 10 miles per year to 34 miles per year (16 kilometers to 54 kilometers). This acceleration could mark the beginning of a reversal in the magnetic field, but scientists can’t really tell with his less than 200 years of data.
Earth’s magnetic field reverses on the following time scales: 100,000 to 1 million years. Scientists can find out how often a magnetic field reverses by: looking at volcanic rocks In the sea.
these rocks Understand direction and strength Therefore, by measuring the age of these rocks, we can better understand how the Earth’s magnetic field has changed. evolved over time.
Magnetic field reversals may be slow from a human perspective, but rapid from a geological perspective. The reversal usually takes several thousand years, but during this time the orientation of the magnetosphere changes, expose more of the earth To cosmic radiation. These events are change ozone concentration In the atmosphere.
Scientists cannot say with confidence when the next magnetic field reversal will occur, but we can continue to map and track the movement of Earth’s magnetic north.
This article is republished from conversationis a nonprofit, independent news organization providing facts and analysis that help you understand our complex world.
It was written by: Ofer Cohen, Lowell University.
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Ofer Cohen is based at the University of Massachusetts Lowell. Universities benefit in terms of exposure and visibility from published articles written by their faculty. Ofer Cohen received her NASA funding related in some way to the article.