What is a magnetic field?A magnetic field is a vector field. It is located near a magnet, electric current, or a changing electric field where magnetic forces can be observed.The magnetic field of the Earth makes the magnetic compass needles and other permanent magnets like a bar magnet line up in the direction of the magnetic field. The magnetic field force can move an electrically charged particle in a spiral or circular path. This magnetic field force exerted on electric currents moving through wires in a magnetic field is the basis of the operation of electric motors. A magnetized ring magnet rolls itself up to align with the local magnetic field. The north pole of this magnet points down, making a sharp angle. Palaeomagnetism or paleomagnetism studies the record of the Earth’s magnetic field in sediment, rocks, and other archaeological materials. Rocks contain magnetic minerals that can lock in a history of the intensity and the direction of the magnetic field belonging to the time in which they are formed. This information is crucial and helps understand how the Earth’s magnetic field behaved previously. This also helps to identify the previous location of the tectonic plates.Like reading this article? Want to know more? Let’s move on. If you like reading this article, you may also enjoy reading about the drinking straw ban and the Deimos.Earth’s Magnetic Field: Definition With ExampleWhat is the reason behind Earth’s magnetic field? How do these magnetic properties originate? The fact that a compass needle used on the surface of the Earth always points towards North shows that there exists a powerful magnetic field surrounding the Earth.The Earth’s interior core acts as an electromagnet. The Earth’s crust is solid; however, the Earth’s core is surrounded by a mixture of metals. This mixture contains metals like nickel and molten iron, and Earth’s magnetic field results from the electrical currents that flow through this molten core. It is very interesting to note that these electric currents flow at speeds of thousands of mi (km) in an hour, and they are hundreds of mi (km) in width. These currents flow like this as the Earth continues to rotate. This magnetic field is very powerful and passes through the core of the Earth, into its crust, and then it enters space. A mathematical model designed in a computer created a picture of this magnetic field. The picture depicted the inner-circle or the solid inner core surrounded by the area between adjoining circles or the outer core containing molten metals. The Earth’s outer core has currents flowing through it while the lines of force travel outward through the leftover area of the interior of the Earth. A stronger magnetic field would have been the result had the Earth rotated faster on its rotation axis. A stronger magnetic field would have resulted if the Earth had a liquid core larger than the present one.Different Layers Of Earth With Different PropertiesWhat are the different layers of the Earth? The division of the Earth can be explained in two ways. One is the mechanical way, and the other is the chemical way. Rheologically (the study of the liquid states) or mechanically, the Earth can be divided into various levels like the asthenosphere, lithosphere, mesospheric mantle, the inner core, and the outer core. The chemical division, which is the more popular of the two, divides the Earth into the crust, the mantle, and the core.The mantle is further subdivided into the lower mantle and the upper mantle. The core is further subdivided into the outer and inner core. The outer one lies in a liquid state, and the inner core has a solid state while the mantle is solid. This is the difference in relative melting points of the different layers. The increase in both temperature and pressure with an increase in depth also contributes to these particular states’ formation. At the Earth’s surface, nickel and iron alloys are solid because of a low temperature. In the upper portion of the mantle, the silicates that are present are usually solid. However, there are local regions of molten materials that lead to limitations in viscosity. The lower portion of the mantle is under a lot of pressure. It has a lower viscosity than the upper portion of the mantle. The outer part of the core with metals like nickel and iron is liquid because the temperature is high. However, the high pressure that continues to rise towards the inner portion of the core contributes significantly to the changes in the melting point of iron and nickel, thus changing its nature into a solid.Significance Of South And North Pole Of EarthWhat is the significance of the South and the North Pole of the Earth?The Earth has three Poles in the Northern Hemisphere; the magnetic North Pole, a geographic North Pole, and the geomagnetic North Pole. The geographic North Pole is located at a distance of 450 mi (725 km) towards the North of Greenland. It is termed the true North. It is located in the middle of the Arctic Ocean. The North Pole is covered in sea ice most of the time. It has six months of daylight and six months of darkness. The geomagnetic poles are challenging to understand scientifically. The magnetic fields generated deep in the Earth’s core change very slowly. Magnetic field reversals from South to North gradually take place over a long time. The Earth’s North magnetic pole is located about 99 mi (160 km) to the South of the geographic North. However, this changes every day. Navigators know the difference between the true North and the magnetic North Pole. The first people to reach the North was Matthew Henson and Robert Peary. Roald Amundsen was the first to visit both the North and South Poles.There are four Poles in the Southern hemisphere: a magnetic Pole, a geographic Pole, a geomagnetic Pole, and a ceremonial Pole. The geographic one is located at the lower part of the axis of the Earth. The longitudes radiate out from this point. This Pole is situated on a glacier that moves about 393 in (10 m) each year. The marker is moved each year, which is done using satellite positioning systems. The ceremonial South Pole is situated a few hundred meters away. A copper pole is planted here. It is surrounded by the flags of the twelve nations that had initially signed the Antarctic Treaty. These nations each have territory on the continent of Antarctica. This pole is usually photographed. The magnetic South is situated in the Antarctic Ocean. This southern pole of the Earth’s field is technically named the south magnetic dip pole. At this point, compass needles which can move both horizontally and vertically, point straight up. The south magnetic pole is rarely found at the exact point as the magnetic fields slowly change over a long period of time. In 1986, this pole was last located with precision at a latitude measuring 65.3º S and a longitude measuring 140 º E. The distance can vary up to several kilometers in a year.Is Earth losing its magnetic field?What is happening to the Earth’s magnetic field? Is the Earth losing its magnetic field?The Earth’s magnetic field is reducing in strength over time and is moving its magnetic North from Northern Canada towards Siberia. This has been happening over the last two hundred years. However, in the recent period, this speed has increased considerably, reaching up to the level of 30 mph (48 kph). Is the Earth on the verge of a geomagnetic reversal? Are the magnetic N & S going to reverse their positions? Pole reversals arise spontaneously. The Sun’s magnetic field reverses itself every eleven years. The last reversal of the Earth’s magnetic field took 780,000 years ago. How will such a reversal affect creatures? Juveniles of the loggerhead turtles traverse far into the Atlantic Ocean from their underground nests in the pristine beaches of Florida. They return to the same beaches from where they had started after many years. They can navigate such long distances by detecting the magnetic field’s direction and strength. Many other creatures like whales, salmon, birds use Earth’s magnetism to find their ways. A magnetic reversal would seriously affect these lives. The magnetic field also protects life on Earth from the stream of electrically charged particles from the Sun. They also protect lives from the cosmic rays (atomic nuclei and protons) coming from the deeper layers of space. A magnetic reversal weakens this protective shield considerably and may lead to massive effects.Did You Know?Magnetic declination or magnetic variation is the angle created because the magnetic N & S poles and the geographic N & S poles are not exactly the same.A bar magnet is made from a ferromagnetic substance.The solar wind is called a stream of electrically charged particles released from the upper layers of the atmosphere surrounding the Sun (termed the corona).Robert Norman and Georg Hartmann independently discovered the meaning of a magnetic inclination for the first time.Compasses used in the Southern Hemisphere are marked to point North.Neodymium(Nd) magnets are the strongest magnets found in the world. They are permanent in nature. They are made from an alloy of iron, neodymium, and boron. They have a Nd2Fe14B structure. These magnets are made from rare earth elements.When an efficient energy exchange takes place from the solar wind into the space region surrounding the Earth, a significant disturbance occurs in the Earth’s magnetosphere. This is termed a geomagnetic storm. Variations in the solar wind contribute to the formation of these storms. The solar wind produces significant changes in the plasmas, currents, and fields in the magnetosphere of the Earth. Geomagnetic storms are a product of several conditions like sustained periods of high-speed solar wind and a magnetic field of the solar wind directed southwards, opposite to the direction of the magnetic field of the Earth. Also, this should be situated on the dayside of the Earth’s magnetosphere. If this condition prevails, an energy exchange takes place between the solar wind and the magnetosphere of the Earth. Magnetic storms are also called solar storms.Geomagnetic observatories are used to forecast and measure magnetic conditions that can affect electric power, communications, and other anthropogenic activities.Here at Kidadl, we have carefully created many interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for fiction or truth: Earth is a magnet, amazing facts about Earth’s surface, then why not take a look at why do moths like light, amazing moth insects facts, or why do huskies talk? Can huskies really communicate?
What is a magnetic field?
