Earth's magnetic field

1836: 2768: 2316:. Using magnetic instruments adapted from airborne magnetic anomaly detectors developed during World War II to detect submarines, the magnetic variations across the ocean floor have been mapped. Basalt — the iron-rich, volcanic rock making up the ocean floor — contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. The distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these magnetic variations have provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials record the Earth's magnetic field. 2740: 1286: 1274: 2340: 1584: 1802:(seemingly random) fluctuation. An instantaneous measurement of it, or several measurements of it across the span of decades or centuries, are not sufficient to extrapolate an overall trend in the field strength. It has gone up and down in the past for unknown reasons. Also, noting the local intensity of the dipole field (or its fluctuation) is insufficient to characterize Earth's magnetic field as a whole, as it is not strictly a dipole field. The dipole component of Earth's field can diminish even while the total magnetic field remains the same or increases. 1650: 1142: 1335: 1592: 1262: 1741:, cools to form new basaltic crust on both sides of the ridge, and is carried away from it by seafloor spreading. As it cools, it records the direction of the Earth's field. When the Earth's field reverses, new basalt records the reversed direction. The result is a series of stripes that are symmetric about the ridge. A ship towing a magnetometer on the surface of the ocean can detect these stripes and infer the age of the ocean floor below. This provides information on the rate at which seafloor has spread in the past. 1787: 1302: 7474: 2754: 856: 47: 2579:, and higher order terms drop off increasingly rapidly with the radius. The radius of the outer core is about half of the radius of the Earth. If the field at the core-mantle boundary is fit to spherical harmonics, the dipole part is smaller by a factor of about 8 at the surface, the quadrupole part by a factor of 16, and so on. Thus, only the components with large wavelengths can be noticeable at the surface. From a variety of arguments, it is usually assumed that only terms up to degree 1504: 7222: 1382: 8551: 7486: 7234: 6755: 1320:, with its south pole pointing towards the geomagnetic North Pole. This may seem surprising, but the north pole of a magnet is so defined because, if allowed to rotate freely, it points roughly northward (in the geographic sense). Since the north pole of a magnet attracts the south poles of other magnets and repels the north poles, it must be attracted to the south pole of Earth's magnet. The dipolar field accounts for 80–90% of the field in most locations. 6854: 2294: 2376: 2174: 7246: 7498: 6767: 4999: 2113:. The temperature increases towards the center of the Earth, and the higher temperature of the fluid lower down makes it buoyant. This buoyancy is enhanced by chemical separation: As the core cools, some of the molten iron solidifies and is plated to the inner core. In the process, lighter elements are left behind in the fluid, making it lighter. This is called 1347:

and –90° (upwards) at the South Magnetic Pole. The two poles wander independently of each other and are not directly opposite each other on the globe. Movements of up to 40 kilometres (25 mi) per year have been observed for the North Magnetic Pole. Over the last 180 years, the North Magnetic Pole has been migrating northwestward, from Cape Adelaide in the

1637:, Oregon appeared to suggest the magnetic field once shifted at a rate of up to 6° per day at some time in Earth's history, a surprising result. However, in 2014 one of the original authors published a new study which found the results were actually due to the continuous thermal demagnitization of the lava, not to a shift in the magnetic field. 2387:. This was first done by Carl Friedrich Gauss. Spherical harmonics are functions that oscillate over the surface of a sphere. They are the product of two functions, one that depends on latitude and one on longitude. The function of longitude is zero along zero or more great circles passing through the North and South Poles; the number of such 2177: 2720:. Some researchers have found that cows and wild deer tend to align their bodies north–south while relaxing, but not when the animals are under high-voltage power lines, suggesting that magnetism is responsible. Other researchers reported in 2011 that they could not replicate those findings using different 2176: 1241:. Maps typically include information on the declination as an angle or a small diagram showing the relationship between magnetic north and true north. Information on declination for a region can be represented by a chart with isogonic lines (contour lines with each line representing a fixed declination). 2181: 2180: 2175: 2727:

Very weak electromagnetic fields disrupt the magnetic compass used by European robins and other songbirds, which use the Earth's magnetic field to navigate. Neither power lines nor cellphone signals are to blame for the electromagnetic field effect on the birds; instead, the culprits have frequencies

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The positions of the magnetic poles can be defined in at least two ways: locally or globally. The local definition is the point where the magnetic field is vertical. This can be determined by measuring the inclination. The inclination of the Earth's field is 90° (downwards) at the North Magnetic Pole

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Historically, the north and south poles of a magnet were first defined by the Earth's magnetic field, not vice versa, since one of the first uses for a magnet was as a compass needle. A magnet's North pole is defined as the pole that is attracted by the Earth's North Magnetic Pole when the magnet is

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contributed to a growing body of evidence that the Earth's magnetic field cycles with intensity every 200 million years. The lead author stated that "Our findings, when considered alongside the existing datasets, support the existence of an approximately 200-million-year-long cycle in the strength of

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Earth's magnetic field deflects most of the solar wind, whose charged particles would otherwise strip away the ozone layer that protects the Earth from harmful ultraviolet radiation. One stripping mechanism is for gas to be caught in bubbles of the magnetic field, which are ripped off by solar winds.

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dynamo models, ones that determine both the fluid motions and the magnetic field, were developed by two groups in 1995, one in Japan and one in the United States. The latter received attention because it successfully reproduced some of the characteristics of the Earth's field, including geomagnetic

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Starting in the late 1800s and throughout the 1900s and later, the overall geomagnetic field has become weaker; the present strong deterioration corresponds to a 10–15% decline and has accelerated since 2000; geomagnetic intensity has declined almost continuously from a maximum 35% above the modern

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The global definition of the Earth's field is based on a mathematical model. If a line is drawn through the center of the Earth, parallel to the moment of the best-fitting magnetic dipole, the two positions where it intersects the Earth's surface are called the North and South geomagnetic poles. If

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Electric currents induced in the ionosphere generate magnetic fields (ionospheric dynamo region). Such a field is always generated near where the atmosphere is closest to the Sun, causing daily alterations that can deflect surface magnetic fields by as much as 1°. Typical daily variations of field

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The oceans contribute to Earth's magnetic field. Seawater is an electrical conductor, and therefore interacts with the magnetic field. As the tides cycle around the ocean basins, the ocean water essentially tries to pull the geomagnetic field lines along. Because the salty water is only slightly

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in which the solar wind would have had a magnetic field orders of magnitude larger than the present solar wind. However, much of the field may have been screened out by the Earth's mantle. An alternative source is currents in the core-mantle boundary driven by chemical reactions or variations in

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The direction and intensity of the dipole change over time. Over the last two centuries the dipole strength has been decreasing at a rate of about 6.3% per century. At this rate of decrease, the field would be negligible in about 1600 years. However, this strength is about average for the last 7

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Finlay, C. C.; Maus, S.; Beggan, C. D.; Bondar, T. N.; Chambodut, A.; Chernova, T. A.; Chulliat, A.; Golovkov, V. P.; Hamilton, B.; Hamoudi, M.; Holme, R.; Hulot, G.; Kuang, W.; Langlais, B.; Lesur, V.; Lowes, F. J.; Lühr, H.; Macmillan, S.; Mandea, M.; McLean, S.; Manoj, C.; Menvielle, M.;

2447:. Analyses of the Earth's magnetic field use a modified version of the usual spherical harmonics that differ by a multiplicative factor. A least-squares fit to the magnetic field measurements gives the Earth's field as the sum of spherical harmonics, each multiplied by the best-fitting 1315:

Near the surface of the Earth, its magnetic field can be closely approximated by the field of a magnetic dipole positioned at the center of the Earth and tilted at an angle of about 11° with respect to the rotational axis of the Earth. The dipole is roughly equivalent to a powerful bar

2102:. Even in a fluid with a finite conductivity, new field is generated by stretching field lines as the fluid moves in ways that deform it. This process could go on generating new field indefinitely, were it not that as the magnetic field increases in strength, it resists fluid motion. 1640:

In July 2020 scientists report that analysis of simulations and a recent observational field model show that maximum rates of directional change of Earth's magnetic field reached ~10° per year – almost 100 times faster than current changes and 10 times faster than previously thought.

1990: 2179: 863:'s field in a period of normal polarity between reversals. The lines represent magnetic field lines, blue when the field points towards the center and yellow when away. The rotation axis of Earth is centered and vertical. The dense clusters of lines are within Earth's core. 2144:(MHD) of the Earth's interior. Simulation of the MHD equations is performed on a 3D grid of points and the fineness of the grid, which in part determines the realism of the solutions, is limited mainly by computer power. For decades, theorists were confined to creating 1454:

Some of the charged particles do get into the magnetosphere. These spiral around field lines, bouncing back and forth between the poles several times per second. In addition, positive ions slowly drift westward and negative ions drift eastward, giving rise to a

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computer models in which the fluid motion is chosen in advance and the effect on the magnetic field calculated. Kinematic dynamo theory was mainly a matter of trying different flow geometries and testing whether such geometries could sustain a dynamo.

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At any location, the Earth's magnetic field can be represented by a three-dimensional vector. A typical procedure for measuring its direction is to use a compass to determine the direction of magnetic North. Its angle relative to true North is the

2098:, any change in the magnetic field would be immediately opposed by currents, so the flux through a given volume of fluid could not change. As the fluid moved, the magnetic field would go with it. The theorem describing this effect is called the 2324:

Each measurement of the magnetic field is at a particular place and time. If an accurate estimate of the field at some other place and time is needed, the measurements must be converted to a model and the model used to make predictions.

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Tarduno, J. A.; Cottrell, R. D.; Watkeys, M. K.; Hofmann, A.; Doubrovine, P. V.; Mamajek, E. E.; Liu, D.; Sibeck, D. G.; Neukirch, L. P.; Usui, Y. (4 March 2010). "Geodynamo, Solar Wind, and Magnetopause 3.4 to 3.45 Billion Years Ago".

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show that the magnetic field, which interacts with the solar wind, is reduced when the magnetic orientation is aligned between Sun and Earth – opposite to the previous hypothesis. During forthcoming solar storms, this could result in

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Spherical harmonic analysis can be used to distinguish internal from external sources if measurements are available at more than one height (for example, ground observatories and satellites). In that case, each term with coefficient

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down to a wavelength of 56 kilometers. It was compiled from satellite, marine, aeromagnetic and ground magnetic surveys. As of 2018, the latest version, EMM2017, includes data from The European Space Agency's Swarm satellite

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and SAC-C) and a world network of geomagnetic observatories. The spherical harmonic expansion was truncated at degree 10, with 120 coefficients, until 2000. Subsequent models are truncated at degree 13 (195 coefficients).

1474:, are largely driven by solar activity. If the solar wind is weak, the magnetosphere expands; while if it is strong, it compresses the magnetosphere and more of it gets in. Periods of particularly intense activity, called 2670:. CM attempts to reconcile data with greatly varying temporal and spatial resolution from ground and satellite sources. The latest version as of 2022 is CM5 of 2016. It provides separate components for main field plus 1436:). The inner belt is 1–2 Earth radii out while the outer belt is at 4–7 Earth radii. The plasmasphere and Van Allen belts have partial overlap, with the extent of overlap varying greatly with solar activity. 1207:

and rotates upwards as the latitude decreases until it is horizontal (0°) at the magnetic equator. It continues to rotate upwards until it is straight up at the South Magnetic Pole. Inclination can be measured with a

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at a rate of about 0.2° per year. This drift is not the same everywhere and has varied over time. The globally averaged drift has been westward since about 1400 AD but eastward between about 1000 AD and 1400 AD.

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suspended so it can turn freely. Since opposite poles attract, the North Magnetic Pole of the Earth is really the south pole of its magnetic field (the place where the field is directed downward into the Earth).

1428:. This region begins at a height of 60 km, extends up to 3 or 4 Earth radii, and includes the ionosphere. This region rotates with the Earth. There are also two concentric tire-shaped regions, called the 1904: 2063:

term. In a stationary fluid, the magnetic field declines and any concentrations of field spread out. If the Earth's dynamo shut off, the dipole part would disappear in a few tens of thousands of years.

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An artist's rendering of the structure of a magnetosphere. 1) Bow shock. 2) Magnetosheath. 3) Magnetopause. 4) Magnetosphere. 5) Northern tail lobe. 6) Southern tail lobe.

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Nichols, Claire I. O.; Weiss, Benjamin P.; Eyster, Athena; Martin, Craig R.; Maloof, Adam C.; Kelly, Nigel M.; Zawaski, Mike J.; Mojzsis, Stephen J.; Watson, E. Bruce; Cherniak, Daniele J. (2024).

2178: 1451:. By contrast, astronauts on the Moon risk exposure to radiation. Anyone who had been on the Moon's surface during a particularly violent solar eruption in 2005 would have received a lethal dose. 1363:

the Earth's magnetic field were perfectly dipolar, the geomagnetic poles and magnetic dip poles would coincide and compasses would point towards them. However, the Earth's field has a significant

1162:(μT), with 1 G = 100 μT. A nanotesla is also referred to as a gamma (γ). The Earth's field ranges between approximately 22 and 67 μT (0.22 and 0.67 G). By comparison, a strong 937:

corresponds to the north pole of Earth's magnetic field (because opposite magnetic poles attract and the north end of a magnet, like a compass needle, points toward Earth's South magnetic field,

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A dynamo can amplify a magnetic field, but it needs a "seed" field to get it started. For the Earth, this could have been an external magnetic field. Early in its history the Sun went through a

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Coe, R. S.; Jarboe, N. A.; Le Goff, M.; Petersen, N. (15 August 2014). "Demise of the rapid-field-change hypothesis at Steens Mountain: The crucial role of continuous thermal demagnetization".

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with a presently accelerating rate—10 kilometres (6.2 mi) per year at the beginning of the 1900s, up to 40 kilometres (25 mi) per year in 2003, and since then has only accelerated.

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Michaelis, I.; Olsen, N.; Rauberg, J.; Rother, M.; Sabaka, T. J.; Tangborn, A.; Tøffner-Clausen, L.; Thébault, E.; Thomson, A. W. P.; Wardinski, I.; Wei, Z.; Zvereva, T. I. (December 2010).

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Declination is positive for an eastward deviation of the field relative to true north. It can be estimated by comparing the magnetic north–south heading on a compass with the direction of a

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The strength of the interaction depends also on the temperature of the ocean water. The entire heat stored in the ocean can now be inferred from observations of the Earth's magnetic field.

2507:– determine the direction and magnitude of the dipole contribution. The best fitting dipole is tilted at an angle of about 10° with respect to the rotational axis, as described earlier. 1832:

The Earth's magnetic field is believed to be generated by electric currents in the conductive iron alloys of its core, created by convection currents due to heat escaping from the core.

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fluids. The Earth's field originates in its core. This is a region of iron alloys extending to about 3400 km (the radius of the Earth is 6370 km). It is divided into a solid

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value, from circa year 1 AD. The rate of decrease and the current strength are within the normal range of variation, as shown by the record of past magnetic fields recorded in rocks.

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The inclination is given by an angle that can assume values between −90° (up) to 90° (down). In the northern hemisphere, the field points downwards. It is straight down at the

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The above models only take into account the "main field" at the core-mantle boundary. Although generally good enough for navigation, higher-accuracy use cases require smaller-scale

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is spreading, while the stability of the geomagnetic poles between reversals has allowed paleomagnetism to track the past motion of continents. Reversals also provide the basis for

1534:) and magnetosphere, and some changes can be traced to geomagnetic storms or daily variations in currents. Changes over time scales of a year or more mostly reflect changes in the 2092: 4447: 2551:. The increasing terms fit the external sources (currents in the ionosphere and magnetosphere). However, averaged over a few years the external contributions average to zero. 1726:. In sediments, the orientation of magnetic particles acquires a slight bias towards the magnetic field as they are deposited on an ocean floor or lake bottom. This is called 1603:. Over hundreds of years, magnetic declination is observed to vary over tens of degrees. The animation shows how global declinations have changed over the last few centuries. 1482:

erupts above the Sun and sends a shock wave through the Solar System. Such a wave can take just two days to reach the Earth. Geomagnetic storms can cause a lot of disruption;

2239:. Such observatories can measure and forecast magnetic conditions such as magnetic storms that sometimes affect communications, electric power, and other human activities. 1405:, the area where the pressures balance, is the boundary of the magnetosphere. Despite its name, the magnetosphere is asymmetric, with the sunward side being about 10 1459:. This current reduces the magnetic field at the Earth's surface. Particles that penetrate the ionosphere and collide with the atoms there give rise to the lights of the 1401:

The solar wind exerts a pressure, and if it could reach Earth's atmosphere it would erode it. However, it is kept away by the pressure of the Earth's magnetic field. The

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Engels, Svenja; Schneider, Nils-Lasse; Lefeldt, Nele; Hein, Christine Maira; Zapka, Manuela; Michalik, Andreas; Elbers, Dana; Kittel, Achim; Hore, P. J. (2014-05-15).

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A schematic illustrating the relationship between motion of conducting fluid, organized into rolls by the Coriolis force, and the magnetic field the motion generates.

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or less have their origin in the core. These have wavelengths of about 2,000 km (1,200 mi) or less. Smaller features are attributed to crustal anomalies.

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Governments sometimes operate units that specialize in measurement of the Earth's magnetic field. These are geomagnetic observatories, typically part of a national

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in time, with intervals between reversals ranging from less than 0.1 million years to as much as 50 million years. The most recent geomagnetic reversal, called the

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The magnitude of Earth's magnetic field at its surface ranges from 25 to 65 μT (0.25 to 0.65 G). As an approximation, it is represented by a field of a

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Hulot, G.; Eymin, C.; Langlais, B.; Mandea, M.; Olsen, N. (April 2002). "Small-scale structure of the geodynamo inferred from Oersted and Magsat satellite data".

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allowed a comparison indicating a dynamic geodynamo in action that appears to be giving rise to an alternate pole under the Atlantic Ocean west of South Africa.

1859:, which is about 3,800 K (3,530 °C; 6,380 °F). The heat is generated by potential energy released by heavier materials sinking toward the core ( 2592: 604: 3255: 1305:

Relationship between Earth's poles. A1 and A2 are the geographic poles; B1 and B2 are the geomagnetic poles; C1 (south) and C2 (north) are the magnetic poles.

3919: 3562: 1855:. The motion of the liquid in the outer core is driven by heat flow from the inner core, which is about 6,000 K (5,730 °C; 10,340 °F), to the 4948:

Glatzmaier, Gary A.; Roberts, Paul H. (1995). "A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle".

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Earth's magnetic field, predominantly dipolar at its surface, is distorted further out by the solar wind. This is a stream of charged particles leaving the

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For historical data about the main field, the IGRF may be used back to year 1900. A specialized GUFM1 model estimates back to year 1590 using ship's logs.

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The Earth and most of the planets in the Solar System, as well as the Sun and other stars, all generate magnetic fields through the motion of electrically

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Although generally Earth's field is approximately dipolar, with an axis that is nearly aligned with the rotational axis, occasionally the North and South

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between 2 kHz and 5 MHz. These include AM radio signals and ordinary electronic equipment that might be found in businesses or private homes.

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The geomagnetic field changes on time scales from milliseconds to millions of years. Shorter time scales mostly arise from currents in the ionosphere (

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Luhmann, J. G.; Johnson, R. E.; Zhang, M. H. G. (3 November 1992). "Evolutionary impact of sputtering of the Martian atmosphere by O + pickup ions".

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Jackson, Andrew; Jonkers, Art R. T.; Walker, Matthew R. (15 March 2000). "Four centuries of geomagnetic secular variation from historical records".

3758: 2988: 2623:. This model truncates at degree 12 (168 coefficients) with an approximate spatial resolution of 3,000 kilometers. It is the model used by the 1755:, a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies. 952:

are usually located near the geographic poles, they slowly and continuously move over geological time scales, but sufficiently slowly for ordinary

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Towle, J. N. (1984). "The Anomalous Geomagnetic Variation Field and Geoelectric Structure Associated with the Mesa Butte Fault System, Arizona".

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Coe, R. S.; Prévot, M.; Camps, P. (20 April 1995). "New evidence for extraordinarily rapid change of the geomagnetic field during a reversal".

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in calculating geomagnetic fields in the past. Such information in turn is helpful in studying the motions of continents and ocean floors. The

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Kageyama, Akira; Sato, Tetsuya; the Complexity Simulation Group (1 January 1995). "Computer simulation of a magnetohydrodynamic dynamo. II".

1310: 1021:, resulting from scavenging of ions by the solar wind, indicate that the dissipation of the magnetic field of Mars caused a near total loss 7820: 3788:

Jackson, Andrew; Jonkers, Art R. T.; Walker, Matthew R. (2000). "Four centuries of Geomagnetic Secular Variation from Historical Records".

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thermal or electric conductivity. Such effects may still provide a small bias that are part of the boundary conditions for the geodynamo.

1071:, various other organisms, ranging from some types of bacteria to pigeons, use the Earth's magnetic field for orientation and navigation. 8521: 7284: 6452: 2843:

Glatzmaier, Gary A.; Roberts, Paul H. (1995). "A three-dimensional self-consistent computer simulation of a geomagnetic field reversal".

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satellite and later satellites have used 3-axis vector magnetometers to probe the 3-D structure of the Earth's magnetic field. The later

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strength are about 25 nT (one part in 2000), with variations over a few seconds of typically around 1 nT (one part in 50,000).

1985:{\displaystyle {\frac {\partial \mathbf {B} }{\partial t}}=\eta \nabla ^{2}\mathbf {B} +\nabla \times (\mathbf {u} \times \mathbf {B} ),} 6500: 1028:

The study of the past magnetic field of the Earth is known as paleomagnetism. The polarity of the Earth's magnetic field is recorded in

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The average magnetic field in the Earth's outer core was calculated to be 25 gauss, 50 times stronger than the field at the surface.

1778:. In 2024 researchers published evidence from Greenland for the existence of the magnetic field as early as 3,700 million years ago. 1618:

Changes that predate magnetic observatories are recorded in archaeological and geological materials. Such changes are referred to as

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Humans have used compasses for direction finding since the 11th century A.D. and for navigation since the 12th century. Although the

4451: 1657:. Dark areas denote periods where the polarity matches today's polarity, light areas denote periods where that polarity is reversed. 1490:, occurred in 1859. It induced currents strong enough to disrupt telegraph lines, and aurorae were reported as far south as Hawaii. 6771: 6414: 4219:"Ice Age Polarity Reversal Was Global Event: Extremely Brief Reversal of Geomagnetic Field, Climate Variability, and Super Volcano" 1871:

elements in the interior. The pattern of flow is organized by the rotation of the Earth and the presence of the solid inner core.

619: 5895: 3307: 2246:, with over 100 interlinked geomagnetic observatories around the world, has been recording the Earth's magnetic field since 1991. 4514: 2640: 1549:

causing geomagnetic storms, provoking displays of aurorae. The short-term instability of the magnetic field is measured with the

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in the natural background that might be caused by a significant metallic object such as a submerged submarine. Typically, these

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Chulliat, A.; Brown, W.; Alken, P.; Beggan, C.; Nair, M.; Cox, G.; Woods, A.; Macmillan, S.; Meyer, B.; Paniccia, M. (2020).

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The most common way of analyzing the global variations in the Earth's magnetic field is to fit the measurements to a set of

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Simulating the geodynamo by computer requires numerically solving a set of nonlinear partial differential equations for the

2121:, caused by the overall planetary rotation, tends to organize the flow into rolls aligned along the north–south polar axis. 1733:

Thermoremanent magnetization is the main source of the magnetic anomalies around mid-ocean ridges. As the seafloor spreads,

8585: 8526: 4306:"Evidence for a 3.45-billion-year-old magnetic remanence: Hints of an ancient geodynamo from conglomerates of South Africa" 2628: 469: 6024: 3355: 2624: 1181:

over South America while there are maxima over northern Canada, Siberia, and the coast of Antarctica south of Australia.

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in 1832 and has been repeatedly measured since then, showing a relative decay of about 10% over the last 150 years. The

3731: 2636: 4399:"Possible Eoarchean Records of the Geomagnetic Field Preserved in the Isua Supracrustal Belt, Southern West Greenland" 1835: 7837: 7766: 6805: 5642:

Deutschlander, M.; Phillips, J.; Borland, S. (1999). "The case for light-dependent magnetic orientation in animals".

2599:(IGRF). It is updated every five years. The 11th-generation model, IGRF11, was developed using data from satellites ( 71: 5583:

Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences

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Hert, J; Jelinek, L; Pekarek, L; Pavlicek, A (2011). "No alignment of cattle along geomagnetic field lines found".

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Animals, including birds and turtles, can detect the Earth's magnetic field, and use the field to navigate during

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and accelerating to a speed of 200 to 1000 kilometres per second. They carry with them a magnetic field, the

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does shift with time, this wandering is slow enough that a simple compass can remain useful for navigation. Using

8256: 7974: 7277: 6356: 5281: 2667: 2632: 2023: 254: 3332: 8085: 6735: 833: 599: 76: 6235: 3674: 7693: 7635: 7529: 6617: 2406:ℓ. Each harmonic is equivalent to a particular arrangement of magnetic charges at the center of the Earth. A 2170:

that happens about twice per day (M2). Other contributions come from ocean swell, eddies, and even tsunamis.

1891: 1883: 1684: 1578: 1395: 614: 319: 2402:. The function of latitude is zero along zero or more latitude circles; this plus the order is equal to the 1723: 1483: 956:

to remain useful for navigation. However, at irregular intervals averaging several hundred thousand years,

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The intensity of the magnetic field is subject to change over time. A 2021 paleomagnetic study from the

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shows, the intensity tends to decrease from the poles to the equator. A minimum intensity occurs in the

8354: 7858: 7698: 7348: 7270: 7060: 6367:. Information on monitoring and modeling the geomagnetic field. British Geological Survey, August 2005. 6310: 5928: 5151:; Le Mouel, Jean Louis (1988). "Time Variations of the Earth's Magnetic Field: From Daily to Secular". 4792:

Buffett, Bruce A. (2010). "Tidal dissipation and the strength of the Earth's internal magnetic field".

2070: 1886:); and the electric and magnetic fields exert a force on the charges that are flowing in currents (the 1120:) of the field is proportional to the force it exerts on a magnet. Another common representation is in 272: 6490: 2480:, gives the contribution of an isolated magnetic charge, so it is zero. The next three coefficients – 1679:, sediment cores taken from the ocean floors, and seafloor magnetic anomalies. Reversals occur nearly 1626:. The records typically include long periods of small change with occasional large changes reflecting 1285: 1273: 6843: 6403: 2620: 2443: 2313: 2254: 2232: 1860: 1583: 1531: 826: 787: 314: 304: 244: 239: 179: 5335: 4649:"Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows" 4021: 3810: 2675: 2297:

A model of short-wavelength features of Earth's magnetic field, attributed to lithospheric anomalies

8161: 8075: 7868: 7650: 7630: 7522: 7401: 5125: 1519:: map showing locations of observatories and contour lines giving horizontal magnetic intensity in 1429: 324: 3230: 910:: these convection currents are caused by heat escaping from the core, a natural process called a 757: 259: 27:

Magnetic field that extends from the Earth's outer and inner core to where it meets the solar wind

7878: 7751: 7746: 7559: 7358: 6540: 6154: 4648: 4218: 2962: 2686: 2236: 2016: 1185: 637: 164: 154: 149: 6459:

Sweeps are in 10° steps at 10 years intervals. Based on data from: The Institute of Geophysics,

5820: 762: 732: 7873: 7863: 7703: 6720: 6622: 5833:"Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird" 3805: 2821: 2796: 2424:

to two dipoles brought together. A quadrupole field is shown in the lower figure on the right.

2305: 2276: 2258: 1768: 1711: 1539: 1178: 934: 930: 584: 354: 129: 6449: 3435: 3408: 3381: 2371:

circles of equal latitude. The function changes sign each ℓtime it crosses one of these lines.

1878:. The magnetic field is generated by a feedback loop: current loops generate magnetic fields ( 1261: 8575: 8128: 7673: 7312: 7307: 7139: 6798: 6699: 6683: 6579: 6569: 4868: 2745: 1852: 1848: 1771:

in South Africa have concluded that the magnetic field has been present since at least about

1627: 1479: 1033: 907: 682: 369: 359: 309: 299: 5535: 5430: 4564: 4234: 4054: 3938: 2600: 2221: 2166:

conductive, the interaction is relatively weak: the strongest component is from the regular

8289: 8241: 8022: 7708: 6274: 6223: 6199: 6171: 6113: 6058: 5844: 5748: 5690: 5590: 5426: 5319: 5199: 5162: 5088: 5029: 4957: 4922: 4877: 4803: 4685: 4601: 4560: 4478: 4410: 4355: 4317: 4304:

Usui, Yoichi; Tarduno, John A.; Watkeys, Michael; Hofmann, Axel; Cottrell, Rory D. (2009).

4276: 4230: 4114: 4050: 3995: 3934: 3797: 3496: 3027: 2923: 2852: 2791: 2612: 2379:

Example of a quadrupole field. This can also be constructed by moving two dipoles together.

2213: 2141: 2012: 1856: 1844: 1680: 1662: 1566: 1367:

contribution, so the poles do not coincide and compasses do not generally point at either.

1251: 1232: 1064: 957: 807: 707: 672: 424: 289: 189: 174: 109: 1722:, the direction of the field is "frozen" in small minerals as they cool, giving rise to a 46: 8: 8580: 8432: 8389: 8223: 8166: 8017: 8009: 7967: 7490: 7416: 7200: 7164: 7134: 6881: 6833: 6564: 6559: 3882: 3487:

Campbell, Wallace A. (1996). ""Magnetic" pole locations on global charts are incorrect".

3462: 2384: 2334: 1752: 1535: 1364: 1204: 1163: 1045: 1005: 965: 961: 922: 767: 747: 742: 549: 534: 419: 389: 284: 214: 6278: 6227: 6175: 6117: 6062: 5848: 5752: 5694: 5679:"Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants" 5594: 5413:

Finlay, CC; Maus, S; Beggan, CD; Hamoudi, M.; Lowes, FJ; Olsen, N; Thébault, E. (2010).

5323: 5203: 5174: 5166: 5092: 5033: 4961: 4926: 4881: 4807: 4689: 4605: 4482: 4414: 4359: 4321: 4280: 4118: 3999: 3920:"Eastward and westward drift of the Earth's magnetic field for the last three millennia" 3801: 3500: 3031: 2927: 2856: 2339: 8301: 7761: 7333: 7154: 7093: 7045: 6971: 6932: 6863: 6838: 6828: 6648: 6643: 6574: 6378: 6290: 5876: 5811: 5785: 5713: 5678: 5606: 5444: 5223: 5148: 5050: 5017: 4895: 4827: 4379: 4145: 4102: 4011: 3831: 3823: 3667:"Shields Up! A breeze of interstellar helium atoms is blowing through the solar system" 3512: 2868: 2690: 2650:

and other variations to be considered. Some examples are (see geomag.us ref for more):

2647: 2053: 1744: 1691:, takes the dipole axis across the equator and then back to the original polarity. The 1599:

Changes in Earth's magnetic field on a time scale of a year or more are referred to as

1460: 1053: 1041: 1022: 899: 879: 642: 382: 184: 144: 6245:

North Pole, South Pole: The epic quest to solve the great mystery of Earth's magnetism

5242: 4624: 4589: 4103:"Rapid geomagnetic changes inferred from Earth observations and numerical simulations" 3885:(2007). "Dipole Moment Variation". In Gubbins, David; Herrero-Bervera, Emilio (eds.). 3285: 464: 8531: 8513: 8417: 8384: 7793: 7776: 7737: 7683: 7600: 7478: 7426: 7250: 7144: 6607: 6336: 6314: 6248: 6141: 6136: 6099: 6086: 6081: 6044: 6001: 5978: 5955: 5932: 5868: 5860: 5803: 5718: 5659: 5374: 5364: 5215: 5106: 5055: 4969: 4819: 4727: 4701: 4629: 4573: 4548: 4496: 4428: 4371: 4173: 4150: 4132: 3898: 3623: 3516: 3441: 3414: 3387: 3159: 3134: 3109: 3084: 2936: 2911: 2759: 2604: 2408: 2271:

companies also use magnetic detectors to identify naturally occurring anomalies from

2228: 1695:

is an example of an excursion, occurring during the last ice age (41,000 years ago).

1668: 1649: 1475: 1348: 1334: 1141: 702: 6430: 6294: 6265:(1954). "On the relation between telluric currents and the earth's magnetic field". 5815: 5610: 5368: 4899: 4383: 4077:"Simulations show magnetic field can change 10 times faster than previously thought" 3835: 2249:

The military determines local geomagnetic field characteristics, in order to detect

1591: 8444: 8311: 8296: 8173: 8153: 8095: 7999: 7994: 7939: 7924: 7787: 7431: 7421: 7238: 7159: 7129: 7055: 7040: 6950: 6791: 6704: 6673: 6612: 6282: 6231: 6179: 6131: 6121: 6076: 6066: 5880: 5852: 5795: 5756: 5708: 5698: 5651: 5598: 5487: 5434: 5331: 5327: 5227: 5207: 5190: 5170: 5096: 5079: 5045: 5037: 4965: 4930: 4885: 4831: 4811: 4794: 4693: 4619: 4609: 4568: 4522: 4486: 4418: 4363: 4325: 4284: 4238: 4140: 4122: 4058: 4015: 4003: 3942: 3890: 3815: 3709: 3504: 3179: 3035: 2970: 2941: 2931: 2872: 2860: 2801: 2786: 2711: 2343:

Schematic representation of spherical harmonics on a sphere and their nodal lines.

2288: 2045: 1864: 1738: 1487: 1447:. Many cosmic rays are kept out of the Solar System by the Sun's magnetosphere, or 1425: 1329: 1068: 969: 938: 895: 887: 802: 717: 677: 667: 554: 509: 492: 409: 344: 114: 38: 5448: 4697: 3180:"Magnetoreception | The Lohmann Lab – University of North Carolina at Chapel Hill" 1786: 1595:

Strength of the axial dipole component of Earth's magnetic field from 1600 to 2020

1486:

damaged more than a third of NASA's satellites. The largest documented storm, the

1301: 8439: 8422: 8379: 8369: 8261: 7934: 7929: 7391: 7353: 7179: 6981: 6955: 6902: 6725: 6480: 6467: 6456: 6437: 6343: 5465: 5018:"Estimating global ocean heat content from tidal magnetic satellite observations" 4719: 4217:

Nowaczyk, N. R.; Arz, H. W.; Frank, U.; Kind, J.; Plessen, B. (16 October 2012).

4028: 3894: 3059: 2816: 2811: 2414: 2118: 1799: 1634: 1037: 933:

actually represents the South pole of Earth's magnetic field, and conversely the

918: 737: 662: 657: 524: 399: 364: 224: 124: 5896:"Electromagnetic Interference Disrupts Bird Navigation, Hints at Quantum Action" 3643:

Darrouzet, Fabien; De Keyser, Johan; Escoubet, C. Philippe (10 September 2013).

2431:(function of position) that satisfies certain properties. A magnetic field is a 777: 8554: 8472: 8462: 8326: 8321: 8080: 8070: 7960: 7888: 7668: 7396: 7373: 7363: 7343: 7226: 7174: 7108: 7070: 7065: 7017: 6897: 6653: 6444: 5974: 5041: 4491: 4466: 4242: 4127: 4062: 3946: 2773: 2717: 1692: 1511: 1238: 973: 875: 697: 692: 514: 404: 329: 279: 229: 202: 159: 134: 104: 97: 7473: 5971:

The magnetic field of the earth: paleomagnetism, the core, and the deep mantle

5799: 4265:"Paleomagnetic Evidence for the Existence of the Geomagnetic Field 3.5 Ga Ago" 2946: 2753: 1359:

is the line where the inclination is zero (the magnetic field is horizontal).

1094:. Facing magnetic North, the angle the field makes with the horizontal is the 855: 8569: 8482: 8412: 8364: 8331: 8203: 8193: 8183: 8143: 8138: 7883: 7718: 7713: 7625: 7620: 7545: 7411: 7205: 6986: 6922: 6871: 6504:. Vol. 17 (11th ed.). Cambridge University Press. pp. 353–385. 6495: 6489: 6262: 6162: 5864: 5624: 5126:"The Intensity of the Earth's Magnetic Force Reduced to Absolute Measurement" 5003: 4726:(New millennium ed.). New York: BasicBooks. pp. 13–3, 15–14, 17–2. 4432: 4136: 3052: 2699: 2095: 1887: 1822: 1587:

Estimated declination contours by year, 1590 to 1990 (click to see variation)

1471: 1413:

that extends beyond 200 Earth radii. Sunward of the magnetopause is the

1376: 1049: 977: 812: 797: 782: 722: 434: 349: 334: 249: 234: 139: 6422: 5703: 5439: 5414: 5272: 4367: 4289: 4264: 3735: 8536: 8487: 8477: 8467: 8407: 8188: 8042: 8032: 7914: 7645: 7640: 7615: 7436: 7088: 7012: 6945: 6940: 6907: 6730: 6145: 6126: 6090: 5872: 5807: 5722: 5663: 5602: 5219: 5110: 5059: 4912: 4823: 4705: 4633: 4614: 4500: 4375: 4154: 3819: 3410:

Planet Earth: Cosmology, Geology, and the Evolution of Life and Environment

2887: 2721: 2432: 2428: 2361: 2301: 2125: 1764: 1654: 1562: 1523: 1456: 1444: 1433: 1421: 1406: 1402: 1391: 1352: 1198: 1159: 1155: 1106: 1029: 792: 687: 652: 594: 529: 449: 414: 294: 169: 6509: 6474:

Patterns in Earth's magnetic field that evolve on the order of 1,000 years

6395: 6071: 5655: 2974: 2441:, each component is the derivative of the same scalar function called the 1874:

The mechanism by which the Earth generates a magnetic field is known as a

1610:

A prominent feature in the non-dipolar part of the secular variation is a

1503: 1439:

As well as deflecting the solar wind, the Earth's magnetic field deflects

1145:

Common coordinate systems used for representing the Earth's magnetic field

8284: 8090: 8027: 7919: 7825: 7688: 7678: 7328: 7169: 7035: 6991: 6976: 6302: 4890: 4863: 4423: 4398: 4330: 4305: 3534: 2671: 2268: 2265: 2261:

or towed as an instrument or an array of instruments from surface ships.

2243: 1868: 1703: 1546: 1448: 1410: 1001: 997: 989: 712: 564: 394: 56: 6100:"Deep-Earth reactor: Nuclear fission, helium, and the geomagnetic field" 6025:"Earth's core may have hardened just in time to save its magnetic field" 5969:

Merrill, Ronald T.; McElhinny, Michael W.; McFadden, Phillip L. (1996).

5856: 5556: 4864:"Recent geodynamo simulations and observations of the geomagnetic field" 4815: 2565:. The magnetic field, being a derivative of the potential, drops off as 1687:, occurred about 780,000 years ago. A related phenomenon, a geomagnetic 8374: 8341: 8316: 8198: 8118: 8037: 7660: 7610: 7584: 7579: 7368: 7293: 7149: 7124: 7103: 7080: 7007: 6912: 6554: 6426:, History of the discovery of Earth's magnetic field by David P. Stern. 4646: 3827: 2781: 2420: 2389: 2293: 2167: 2106: 1773: 1440: 1381: 1209: 993: 981: 926: 883: 429: 7221: 6853: 6286: 6183: 5509: 3508: 3279: 3277: 3039: 2304:

detect minute deviations in the Earth's magnetic field caused by iron

1338:

The movement of Earth's North Magnetic Pole across the Canadian arctic

1219:(map of inclination contours) for the Earth's magnetic field is shown 8306: 8251: 8236: 8208: 8178: 8105: 8047: 7909: 7904: 7605: 7574: 7195: 7050: 6917: 6678: 6347:. American Geophysical Union Geomagnetism and Paleomagnetism Section. 4934: 4007: 2864: 2806: 2060: 2059:

The first term on the right hand side of the induction equation is a

1875: 1719: 1707: 1414: 911: 752: 727: 539: 61: 5761: 5736: 5362: 5211: 5101: 5074: 2912:"International Geomagnetic Reference Field: the eleventh generation" 2375: 1424:, a donut-shaped region containing low-energy charged particles, or 1000:

that would otherwise strip away the upper atmosphere, including the

984:

that is defined by the extent of Earth's magnetic field in space or

5466:"The International Geomagnetic Reference Field: A "Health" Warning" 4467:"Earth's magnetic field is acting up and geologists don't know why" 3274: 2554:

The remaining terms predict that the potential of a dipole source (

2418:

is equivalent to two opposing charges brought close together and a

2110: 985: 504: 499: 119: 7514: 5790: 1017:

Calculations of the loss of carbon dioxide from the atmosphere of

8399: 8276: 8246: 8062: 8052: 7756: 7457: 7027: 6814: 5002:

This article incorporates text from this source, which is in the

4988: 2412:

is an isolated magnetic charge, which has never been observed. A

1810: 1790:

Variations in virtual axial dipole moment since the last reversal

1550: 1443:, high-energy charged particles that are mostly from outside the 1250:

Components of the Earth's magnetic field at the surface from the

953: 942: 474: 5677:

Burda, H.; Begall, S.; Cerveny, J.; Neef, J.; Nemec, P. (2009).

3131:

Looking into the Earth: An introduction to Geological Geophysics

8266: 8133: 8113: 7810: 7782: 7564: 6363: 5997: 4101:

Davies, Christopher J.; Constable, Catherine G. (6 July 2020).

2534:

can be split into two terms: one that decreases with radius as

2309: 2217: 2193: 1806: 1751:, part of which is shown in the image. This forms the basis of 1676: 1607:

thousand years, and the current rate of change is not unusual.

1557: 1520: 1464: 1317: 559: 66: 6460: 5415:"Evaluation of candidate geomagnetic field models for IGRF-11" 3308:"Ancient lava reveals secrets of Earth's magnetic field cycle" 2308:, kilns, some types of stone structures, and even ditches and 1052:

rocks and sediments. The field also magnetizes the crust, and

8454: 8231: 8213: 7983: 7262: 4344: 3860: 3645:"Cluster shows plasmasphere interacting with Van Allen belts" 2702:

research has produced models dating back to 10,000 BCE.

1734: 1189:

the Earth's magnetic field related to deep Earth processes."

968:

respectively, abruptly switch places. These reversals of the

860: 6441:, Educational web site by David P. Stern and Mauricio Peredo 5641: 3759:"Sun Often "Tears Out A Wall" In Earth's Solar Storm Shield" 8503: 8123: 7441: 6351: 6104: 6049: 5250: 2663: 2659: 1057: 1018: 903: 6783: 5830: 5775: 5016:

Irrgang, Christopher; Saynisch, Jan; Thomas, Maik (2019).

3642: 2689:(EMM), which extends to degree and order 790 and resolves 2678:, and primary/induced magnetosphere/ionosphere variations. 1882:); a changing magnetic field generates an electric field ( 1805:

The Earth's magnetic north pole is drifting from northern

988:. It extends several tens of thousands of kilometres into 921:

currently tilted at an angle of about 11° with respect to

6236:

10.1130/0016-7606(1984)95<221:TAGVFA>2.0.CO;2

4840:"First Measurement Of Magnetic Field Inside Earth's Core" 4676:

Buffett, B. A. (2000). "Earth's Core and the Geodynamo".

4647:

European Synchrotron Radiation Facility (25 April 2013).

4303: 4172:(2nd ed.). Amsterdam: Elsevier Science. p. 38. 3258:. National High Magnetic Field Laboratory. Archived from 2272: 891: 7952: 5968: 5187: 4779: 4767: 4755: 4396: 4204: 4192: 4040: 3283: 3217: 2902: 2619:(formerly the National Geophysical Data Center) and the 2015:, which is inversely proportional to the product of the 1510:: a set of traces from magnetic observatories showing a 5412: 3596: 3594: 3592: 3590: 3588: 2186:

Sea level magnetic fields observed by satellites (NASA)

6450:

Global evolution/anomaly of the Earth's magnetic field

5676: 4515:"How does the Earth's core generate a magnetic field?" 3533:. Woods Hole Oceanographic Institution. Archived from 2908: 2593:

International Association of Geomagnetism and Aeronomy

1470:

The varying conditions in the magnetosphere, known as

1432:, with high-energy ions (energies from 0.1 to 10 929:

placed at that angle through the center of Earth. The

6337:

Geomagnetism & Paleomagnetism background material

5015: 2073: 1907: 992:, protecting Earth from the charged particles of the 5580: 5274:

Geologic Applications of Modern Aeromagnetic Surveys

4262: 4216: 3787: 3585: 3469:. Dept. of Physics and Astronomy, Georgia State Univ 3079:

McElhinny, Michael W.; McFadden, Phillip L. (2000).

2735: 2244:

International Real-time Magnetic Observatory Network

2212:

The Earth's magnetic field strength was measured by

3017: 2595:maintains a standard global field model called the 1710:, that can carry a permanent magnetic moment. This 5147: 3918:Dumberry, Mathieu; Finlay, Christopher C. (2007). 3859:. Canadian Geological Survey. 2011. Archived from 3379: 2654:The "comprehensive modeling" (CM) approach by the 2086: 1984: 1166:has a field of about 10,000 μT (100 G). 6307:Introduction to Geomagnetically Trapped Radiation 6097: 4947: 4521:. United States Geological Survey. Archived from 3790:Philosophical Transactions of the Royal Society A 3734:. Space Weather Prediction Center. Archived from 3078: 2842: 2435:, but if it is expressed in Cartesian components 1827: 8567: 6098:Hollenbach, D. F.; Herndon, J. M. (2001-09-25). 5468:. National Geophysical Data Center. January 2010 5370:This Dynamic Earth: The Story of Plate Tectonics 5270: 4263:McElhinney, T. N. W.; Senanayake, W. E. (1980). 3875: 2838: 2836: 2643:as well as in many civilian navigation systems. 1545:Frequently, the Earth's magnetosphere is hit by 1417:, the area where the solar wind slows abruptly. 1154:The intensity of the field is often measured in 5948:Our Magnetic Earth: The Science of Geomagnetism 5683:Proceedings of the National Academy of Sciences 5247:Comprehensive Modeling of the Geomagnetic Field 4594:Proceedings of the National Academy of Sciences 4100: 3887:Encyclopedia of Geomagnetism and Paleomagnetism 3413:. UK: Cambridge University Press. p. 228. 3104:Opdyke, Neil D.; Channell, James E. T. (1996). 3074: 3072: 3070: 3068: 1798:The nature of Earth's magnetic field is one of 6445:International Geomagnetic Reference Field 2011 5729: 5561:National Centers for Environmental Information 5460: 5458: 5302: 4995:. Scientific Visualization Studio. 2016-12-30. 4671: 4669: 3985: 3917: 3103: 3062:. Scign.jpl.nasa.gov. Retrieved on 2012-01-27. 2683:National Centers for Environmental Information 2617:National Centers for Environmental Information 1851:, with a radius of 1220 km, and a liquid 1698:The past magnetic field is recorded mostly by 7968: 7530: 7278: 6799: 6525: 6045:"Substructure of the inner core of the Earth" 5154:Annual Review of Earth and Planetary Sciences 4448:"North Magnetic Pole Moving Due to Core Flux" 3613: 3611: 3609: 3556: 3554: 3552: 2833: 2282: 1351:in 1831 to 600 kilometres (370 mi) from 1036:are thus detectable as "stripes" centered on 972:leave a record in rocks that are of value to 834: 6506:(with dozens of tables and several diagrams) 5181: 4950:Physics of the Earth and Planetary Interiors 4590:"Structural Geology of the Earth's Interior" 4403:Journal of Geophysical Research: Solid Earth 4198: 3489:Eos, Transactions American Geophysical Union 3454: 3286:The US/UK World Magnetic Model for 2020–2025 3065: 2194:Currents in the ionosphere and magnetosphere 1056:can be used to search for deposits of metal 882:out into space, where it interacts with the 6539: 5455: 5394: 4983: 4981: 4979: 4861: 4857: 4855: 4666: 4297: 3781: 3756: 3231:"An Overview of the Earth's Magnetic Field" 3128: 2615:, is produced jointly by the United States 2202: 1747:of lava flows has been used to establish a 1718:, can be acquired in more than one way. In 1644: 1409:out but the other side stretching out in a 1220: 1174: 7975: 7961: 7537: 7523: 7285: 7271: 6806: 6792: 6532: 6518: 6391:. National Geographic, September 27, 2004. 5123: 3979: 3606: 3549: 2960: 2083: 1311:Dipole model of the Earth's magnetic field 841: 827: 45: 6418:. Projects in Scientific Computing, 1996. 6135: 6125: 6080: 6070: 5789: 5760: 5712: 5702: 5670: 5438: 5100: 5072: 5049: 4889: 4751: 4749: 4747: 4745: 4743: 4623: 4613: 4572: 4490: 4422: 4329: 4288: 4144: 4126: 3881: 3809: 3620:Physics of space plasmas: an introduction 3380:Serway, Raymond A.; Chris Vuille (2006). 3353: 3333:"Geomagnetism Frequently Asked Questions" 3213: 3211: 3209: 3207: 3205: 3203: 3201: 3199: 3197: 3195: 3129:Mussett, Alan E.; Khan, M. Aftab (2000). 2945: 2935: 2879: 2597:International Geomagnetic Reference Field 1244: 1169:A map of intensity contours is called an 6431:Exploration of the Earth's Magnetosphere 6155:"Magnetic monitoring of Earth and space" 6022: 5922: 5400: 5358: 5356: 4976: 4852: 4549:"Dynamos in planets, stars and galaxies" 4542: 4540: 4446:Lovett, Richard A. (December 24, 2009). 4167: 4034: 3967: 3911: 3695: 3622:. Redwood City, Calif.: Addison-Wesley. 3560: 3486: 3406: 3400: 3356:"The Earth Has More Than One North Pole" 2374: 2338: 2292: 2172: 2160: 2105:The motion of the fluid is sustained by 1834: 1785: 1648: 1590: 1582: 1502: 1498: 1380: 1333: 1300: 1296: 1140: 854: 6042: 5945: 5510:"Geomagnetic and Electric Field Models" 4862:Kono, Masaru; Roberts, Paul H. (2002). 4791: 4773: 4761: 4718: 4675: 3600: 3433: 3427: 2641:International Hydrographic Organization 2611:Another global field model, called the 590:Electromagnetism and special relativity 14: 8568: 6242: 6216:Geological Society of America Bulletin 4780:Merrill, McElhinny & McFadden 1996 4768:Merrill, McElhinny & McFadden 1996 4756:Merrill, McElhinny & McFadden 1996 4740: 4587: 4445: 4205:Merrill, McElhinny & McFadden 1996 4193:Merrill, McElhinny & McFadden 1996 4186: 3847: 3845: 3757:Steigerwald, Bill (16 December 2008). 3647:(Press release). European Space Agency 3386:. USA: Cengage Learning. p. 493. 3373: 3218:Merrill, McElhinny & McFadden 1996 3192: 3153: 2885: 2427:Spherical harmonics can represent any 2328: 1890:). These effects can be combined in a 1758: 7956: 7518: 7266: 6787: 6513: 6487: 6388:Why Does Earth's Magnetic Field Flip? 6213: 6023:Gramling, Carolyn (1 February 2019). 5994:Paleomagnetic Principles and Practice 5991: 5353: 4546: 4537: 4464: 3973: 3889:. Springer-Verlag. pp. 159–161. 3617: 3081:Paleomagnetism: Continents and Oceans 2890:. University of California Santa Cruz 2471:The lowest-degree Gauss coefficient, 2364:passing through the poles, and along 2319: 2040:is the time derivative of the field; 1653:Geomagnetic polarity during the late 894:. The magnetic field is generated by 610:Maxwell equations in curved spacetime 8527:Geology of solar terrestrial planets 7497: 6766: 6301: 6261: 6152: 4310:Geochemistry, Geophysics, Geosystems 3698:"The great solar superstorm of 1859" 3460: 3354:Casselman, Anne (28 February 2008). 3325: 3253: 2989:"Solar wind ripping chunks off Mars" 2963:"Solar wind hammers the ozone layer" 2629:Ministry of Defence (United Kingdom) 2510: 2257:are flown in aircraft like the UK's 1572: 7544: 7245: 5893: 5305:"Basalts from the Deep Ocean Floor" 5175:10.1146/annurev.ea.16.050188.002133 4465:Witze, Alexandra (9 January 2019). 4223:Earth and Planetary Science Letters 4043:Earth and Planetary Science Letters 3927:Earth and Planetary Science Letters 3842: 3763:THEMIS: Understanding space weather 3673:. 27 September 2004. Archived from 3563:"Earth's Inconstant Magnetic Field" 3561:Phillips, Tony (29 December 2003). 2961:Shlermeler, Quirin (3 March 2005). 2625:United States Department of Defense 2135: 2094:), there would be no diffusion. By 925:axis, as if there were an enormous 24: 6015: 5925:Introduction to geomagnetic fields 5490:. National Geophysical Data Center 3335:. National Geophysical Data Center 2995:. 25 November 2008. Archived from 2637:North Atlantic Treaty Organization 2080: 1954: 1937: 1921: 1911: 1894:for the magnetic field called the 1816: 1493: 1074: 25: 8597: 7838:Sura Ionospheric Heating Facility 6329: 6192:"Temperature of the Earth's core" 5778:Journal of Comparative Physiology 5075:"Spectroscopy: NMR down to Earth" 4989:"Ocean Tides and Magnetic Fields" 2916:Geophysical Journal International 2087:{\displaystyle \sigma =\infty \;} 1671:trade places. Evidence for these 1323: 8550: 8549: 7496: 7485: 7484: 7472: 7244: 7233: 7232: 7220: 6852: 6765: 6754: 6753: 6247:. New York, NY: The Experiment. 5240: 4997: 4574:10.1046/j.1468-4004.2002.43309.x 2937:10.1111/j.1365-246X.2010.04804.x 2766: 2752: 2738: 2586: 1972: 1964: 1947: 1915: 1420:Inside the magnetosphere is the 1370: 1284: 1272: 1260: 8257:Human impact on the environment 6357:United States Geological Survey 5887: 5824: 5769: 5644:Journal of Experimental Biology 5635: 5617: 5574: 5549: 5520: 5502: 5480: 5406: 5296: 5264: 5234: 5141: 5117: 5066: 5009: 4941: 4906: 4785: 4724:The Feynman lectures on physics 4712: 4640: 4581: 4507: 4458: 4439: 4390: 4338: 4269:Journal of Geophysical Research 4256: 4210: 4161: 4094: 4069: 3750: 3724: 3689: 3659: 3636: 3523: 3480: 3440:. USA: CRC Press. p. 148. 3347: 3300: 3247: 3223: 3172: 3147: 3122: 2705: 2668:Danish Space Research Institute 2633:Federal Aviation Administration 2572:. Quadrupole terms drop off as 1749:geomagnetic polarity time scale 1728:detrital remanent magnetization 1620:paleomagnetic secular variation 1158:, but is generally reported in 1011: 8086:Climate variability and change 7292: 6491:"Magnetism, Terrestrial" 5332:10.1180/minmag.1965.034.268.32 4170:Geomagnetism in marine geology 3133:. Cambridge University Press. 3097: 3046: 3011: 2981: 2954: 2001:is the velocity of the fluid; 1976: 1960: 1828:Earth's core and the geodynamo 1633:A 1995 study of lava flows on 1226: 1192: 13: 1: 8522:Evolution of the Solar System 7694:Interplanetary magnetic field 7636:Magnetosphere particle motion 6352:National Geomagnetism Program 6043:Herndon, J. M. (1996-01-23). 5923:Campbell, Wallace H. (2003). 5557:"The Enhanced Magnetic Model" 4698:10.1126/science.288.5473.2007 3383:Essentials of college physics 2827: 2393:is the absolute value of the 2007:is the magnetic B-field; and 1892:partial differential equation 1579:Geomagnetic secular variation 1538:, particularly the iron-rich 1484:the "Halloween" storm of 2003 1396:interplanetary magnetic field 1006:harmful ultraviolet radiation 615:Relativistic electromagnetism 8262:Evolutionary history of life 4970:10.1016/0031-9201(95)03049-3 3895:10.1007/978-1-4020-4423-6_67 3437:Static Fields and Potentials 3020:Geophysical Research Letters 2207: 1724:thermoremanent magnetization 1624:paleosecular variation (PSV) 1149: 7: 8586:Magnetic field of the Earth 7432:Precession of the equinoxes 6877:Geological history of Earth 6813: 6741:Charles Thomson Rees Wilson 6639:Upper-atmospheric lightning 6423:The Great Magnet, the Earth 6373:Will Compasses Point South? 5952:University of Chicago Press 5946:Merrill, Ronald T. (2010). 5243:"Satellite Magnetic Models" 2731: 2656:Goddard Space Flight Center 1896:magnetic induction equation 10: 8602: 7699:Heliospheric current sheet 7349:Geophysical fluid dynamics 6850: 6311:Cambridge University Press 5929:Cambridge University Press 5927:(2nd ed.). New York: 5916: 5894:Hsu, Jeremy (9 May 2014). 5488:"The World Magnetic Model" 5042:10.1038/s41598-019-44397-8 4492:10.1038/d41586-019-00007-1 4243:10.1016/j.epsl.2012.06.050 4128:10.1038/s41467-020-16888-0 4063:10.1016/j.epsl.2014.05.036 4020:(also available online at 3947:10.1016/j.epsl.2006.11.026 2709: 2332: 2286: 2283:Crustal magnetic anomalies 2255:magnetic anomaly detectors 1820: 1700:strongly magnetic minerals 1660: 1576: 1374: 1327: 1308: 1230: 1196: 948:While the North and South 340:Liénard–Wiechert potential 8545: 8512: 8496: 8453: 8398: 8340: 8275: 8222: 8152: 8104: 8061: 8008: 7990: 7982: 7897: 7846: 7803: 7727: 7659: 7593: 7552: 7466: 7450: 7382: 7321: 7300: 7214: 7188: 7117: 7079: 7026: 7000: 6964: 6931: 6891:Composition and structure 6890: 6862: 6844:Index of geology articles 6821: 6749: 6713: 6692: 6666: 6631: 6600: 6593: 6547: 6153:Love, Jeffrey J. (2008). 5800:10.1007/s00359-011-0628-7 5271:William F. Hanna (1987). 5073:Stepišnik, Janez (2006). 4168:Vacquier, Victor (1972). 3618:Parks, George K. (1991). 3531:"The Magnetic North Pole" 3407:Emiliani, Cesare (1992). 2621:British Geological Survey 2314:archaeological geophysics 2233:British Geological Survey 1861:planetary differentiation 1781: 1763:Paleomagnetic studies of 1685:Brunhes–Matuyama reversal 1532:ionospheric dynamo region 1430:Van Allen radiation belts 1004:that protects Earth from 605:Mathematical descriptions 315:Electromagnetic radiation 305:Electromagnetic induction 245:Magnetic vector potential 240:Magnetic scalar potential 8532:Location in the Universe 8463:Antarctic/Southern Ocean 8162:List of sovereign states 7651:Van Allen radiation belt 7631:Magnetosphere chronology 6243:Turner, Gillian (2011). 5737:"Biology: Electric cows" 5419:Earth, Planets and Space 4553:Astronomy and Geophysics 2203:Measurement and analysis 2115:compositional convection 2067:In a perfect conductor ( 1645:Magnetic field reversals 7560:Atmospheric circulation 7359:Near-surface geophysics 6541:Atmospheric electricity 6501:Encyclopædia Britannica 6488:Chree, Charles (1911). 6410:. about pole reversals) 5704:10.1073/pnas.0811194106 5629:geomagia.gfz-potsdam.de 5625:"The GEOMAGIA database" 5440:10.5047/eps.2010.11.005 5431:2010EP&S...62..787F 5303:G. D. Nicholls (1965). 4565:2002A&G....43c...9W 4368:10.1126/science.1183445 4290:10.1029/JB085iB07p03523 4235:2012E&PSL.351...54N 4055:2014E&PSL.400..302C 3939:2007E&PSL.254..146D 3702:Technology Through Time 3696:Odenwald, Sten (2010). 3154:Temple, Robert (2006). 2687:Enhanced Magnetic Model 2237:Eskdalemuir Observatory 2100:frozen-in-field theorem 2017:electrical conductivity 1776: million years ago 1186:University of Liverpool 902:of a mixture of molten 859:Computer simulation of 155:Electrostatic induction 150:Electrostatic discharge 7570:Earth's magnetic field 7407:Earth's magnetic field 6721:Georg Wilhelm Richmann 6700:Electrodynamic tethers 6585:Earth's magnetic field 6198:. 1999. Archived from 6196:NEWTON Ask a Scientist 6127:10.1073/pnas.201393998 5603:10.1098/rsta.2000.0569 5312:Mineralogical Magazine 4615:10.1073/pnas.76.9.4192 4588:Jordan, T. H. (1979). 3820:10.1098/rsta.2000.0569 3765:. NASA. Archived from 3461:Nave, Carl R. (2010). 3053:Structure of the Earth 2822:South Atlantic Anomaly 2797:Magnetic field of Mars 2380: 2372: 2298: 2277:Kursk Magnetic Anomaly 2187: 2088: 1986: 1880:Ampère's circuital law 1867:) as well as decay of 1840: 1791: 1767:lava in Australia and 1712:remanent magnetization 1658: 1628:geomagnetic excursions 1596: 1588: 1527: 1387: 1339: 1306: 1245:Geographical variation 1179:South Atlantic Anomaly 1146: 1034:reversals of the field 958:Earth's field reverses 935:South geomagnetic pole 931:North geomagnetic pole 868:Earth's magnetic field 864: 585:Electromagnetic tensor 8242:Biogeochemical cycles 8167:dependent territories 7674:Coronal mass ejection 7594:Earth's magnetosphere 7479:Geophysics portal 7402:Earth's energy budget 7140:Environmental geology 6684:Equatorial electrojet 6580:Atmospheric chemistry 6415:When North Goes South 6072:10.1073/pnas.93.2.646 5656:10.1242/jeb.202.8.891 5363:Jacqueline W. Kious; 4869:Reviews of Geophysics 4547:Weiss, Nigel (2002). 4454:on December 28, 2009. 4107:Nature Communications 3434:Manners, Joy (2000). 3106:Magnetic Stratigraphy 2975:10.1038/news050228-12 2746:Earth sciences portal 2378: 2342: 2296: 2185: 2161:Effect of ocean tides 2089: 1987: 1838: 1789: 1673:geomagnetic reversals 1652: 1594: 1586: 1567:artificial satellites 1506: 1499:Short-term variations 1480:coronal mass ejection 1386:7) Plasmasphere. 1384: 1337: 1304: 1297:Dipolar approximation 1144: 898:due to the motion of 858: 578:Covariant formulation 370:Synchrotron radiation 310:Electromagnetic pulse 300:Electromagnetic field 18:Terrestrial magnetism 8290:Computer cartography 8023:Prebiotic atmosphere 7847:Other magnetospheres 7709:Solar particle event 7099:Planetary geophysics 6570:Atmospheric dynamics 5992:Tauxe, Lisa (1998). 5373:. USGS. p. 17. 4891:10.1029/2000RG000102 4846:. December 17, 2010. 4424:10.1029/2023JB027706 4331:10.1029/2009GC002496 3883:Constable, Catherine 3235:www.geomag.bgs.ac.uk 2792:Geomagnetic latitude 2631:, the United States 2613:World Magnetic Model 2355:is equal to 0 along 2275:bodies, such as the 2214:Carl Friedrich Gauss 2142:magnetohydrodynamics 2071: 2013:magnetic diffusivity 1905: 1857:core-mantle boundary 1663:Geomagnetic reversal 1463:while also emitting 1252:World Magnetic Model 1233:Magnetic declination 1175:World Magnetic Model 1138:(Down) coordinates. 1065:magnetic declination 966:South Magnetic Poles 886:, a stream of 870:, also known as the 620:Stress–energy tensor 545:Reluctance (complex) 290:Displacement current 8433:Geologic time scale 8154:Culture and society 8018:Atmosphere of Earth 7451:Related disciplines 7417:Geothermal gradient 7201:Petroleum geologist 7165:Forensic geophysics 7135:Engineering geology 6882:Timeline of geology 6834:Glossary of geology 6565:Atmospheric physics 6560:Atmospheric science 6279:1954Geop...19..281W 6228:1984GSAB...95..221T 6176:2008PhT....61b..31H 6118:2001PNAS...9811085H 6063:1996PNAS...93..646H 5857:10.1038/nature13290 5849:2014Natur.509..353E 5753:2009Natur.458Q.389. 5747:(7237): 389. 2009. 5695:2009PNAS..106.5708B 5595:2000RSPTA.358..957J 5528:"Model information" 5324:1965MinM...34..373N 5204:2002Natur.416..620H 5167:1988AREPS..16..389C 5149:Courtillot, Vincent 5124:Gauss, C.F (1832). 5093:2006Natur.439..799S 5034:2019NatSR...9.7893I 4962:1995PEPI...91...63G 4927:1995PhPl....2.1421K 4882:2002RvGeo..40.1013K 4816:10.1038/nature09643 4808:2010Natur.468..952B 4720:Feynman, Richard P. 4690:2000Sci...288.2007B 4684:(5473): 2007–2012. 4606:1979PNAS...76.4192J 4483:2019Natur.565..143W 4415:2024JGRB..12927706N 4360:2010Sci...327.1238T 4354:(5970): 1238–1240. 4322:2009GGG....10.9Z07U 4281:1980JGR....85.3523M 4119:2020NatCo..11.3371D 4000:1995Natur.374..687C 3853:"Secular variation" 3802:2000RSPTA.358..957J 3501:1996EOSTr..77..345C 3360:Scientific American 3254:Palm, Eric (2011). 3156:The Genius of China 3032:1992GeoRL..19.2151L 2928:2010GeoJI.183.1216F 2857:1995Natur.377..203G 2385:spherical harmonics 2335:Multipole expansion 2329:Spherical harmonics 2231:, for example, the 2109:, motion driven by 1759:Earliest appearance 1753:magnetostratigraphy 1565:and disruptions in 1478:, can occur when a 1205:North Magnetic Pole 1164:refrigerator magnet 1046:magnetostratigraphy 900:convection currents 890:emanating from the 535:Magnetomotive force 420:Electromotive force 390:Alternating current 325:Jefimenko equations 285:Cyclotron radiation 8428:Geological history 8302:Geodetic astronomy 7334:Geophysical survey 7227:Geology portal 7155:Geologic modelling 7094:Geophysical survey 7046:Geodetic astronomy 6972:Structural geology 6933:Historical geology 6864:History of geology 6839:History of geology 6829:Outline of geology 6608:Radio atmospherics 6575:Atmospheric dynamo 6479:2018-07-20 at the 6466:2007-10-31 at the 6455:2016-06-24 at the 6436:2013-02-14 at the 6379:The New York Times 6370:William J. Broad, 6342:2013-03-03 at the 5532:ccmc.gsfc.nasa.gov 5022:Scientific Reports 4915:Physics of Plasmas 4525:on 18 January 2015 4207:, pp. 148–155 4027:2012-03-14 at the 3738:on 22 October 2013 3712:on 12 October 2009 3573:on 1 November 2022 3108:. Academic Press. 3083:. Academic Press. 3058:2013-03-15 at the 2947:20.500.11850/27303 2886:Glatzmaier, Gary. 2691:magnetic anomalies 2648:magnetic anomalies 2444:magnetic potential 2381: 2373: 2320:Statistical models 2299: 2188: 2084: 1982: 1841: 1792: 1745:Radiometric dating 1737:wells up from the 1659: 1597: 1589: 1528: 1476:geomagnetic storms 1388: 1340: 1307: 1147: 1054:magnetic anomalies 980:extends above the 923:Earth's rotational 908:Earth's outer core 878:that extends from 865: 383:Electrical network 220:Gauss magnetic law 185:Static electricity 145:Electric potential 8563: 8562: 8514:Planetary science 8497:Natural satellite 8418:Extremes on Earth 8385:Signal processing 7950: 7949: 7804:Research projects 7772: 7743: 7684:Geomagnetic storm 7601:Birkeland current 7512: 7511: 7427:Mantle convection 7260: 7259: 7145:Planetary geology 7061:Planetary geodesy 6781: 6780: 6662: 6661: 6632:Optical emissions 6601:ELF/VLF emissions 6320:978-0-521-61611-9 6287:10.1190/1.1437994 6254:978-1-61519-031-7 6184:10.1063/1.2883907 6007:978-0-7923-5258-7 5984:978-0-12-491246-5 5961:978-0-226-52050-6 5938:978-0-521-52953-2 5843:(7500): 353–356. 5589:(1768): 957–990. 5380:978-0-16-048220-5 5365:Robert I. Tilling 5198:(6881): 620–623. 5087:(7078): 799–801. 4802:(7326): 952–954. 4733:978-0-465-02494-0 4477:(7738): 143–144. 4179:978-0-08-087042-7 3994:(6524): 687–692. 3904:978-1-4020-3992-8 3796:(1768): 957–990. 3629:978-0-201-50821-5 3537:on 19 August 2013 3509:10.1029/96EO00237 3447:978-0-7503-0718-5 3420:978-0-521-40949-0 3393:978-0-495-10619-7 3165:978-0-671-62028-8 3158:. Andre Deutsch. 3140:978-0-521-78085-8 3115:978-0-12-527470-8 3090:978-0-12-483355-5 3040:10.1029/92GL02485 3026:(21): 2151–2154. 2851:(6546): 203–209. 2760:Geophysics portal 2511:Radial dependence 2449:Gauss coefficient 2229:Geological survey 2183: 1928: 1669:geomagnetic poles 1601:secular variation 1573:Secular variation 1349:Boothia Peninsula 1023:of its atmosphere 970:geomagnetic poles 896:electric currents 888:charged particles 872:geomagnetic field 851: 850: 550:Reluctance (real) 520:Gyrator–capacitor 465:Resonant cavities 355:Maxwell equations 16:(Redirected from 8593: 8553: 8552: 8445:History of Earth 8096:Paleoclimatology 7977: 7970: 7963: 7954: 7953: 7788:Van Allen Probes 7770: 7741: 7553:Submagnetosphere 7539: 7532: 7525: 7516: 7515: 7500: 7499: 7488: 7487: 7477: 7476: 7422:Gravity of Earth 7287: 7280: 7273: 7264: 7263: 7248: 7247: 7236: 7235: 7225: 7224: 7160:Forensic geology 7130:Economic geology 7056:Gravity of Earth 6951:Paleoclimatology 6856: 6808: 6801: 6794: 6785: 6784: 6769: 6768: 6757: 6756: 6705:Magnetotellurics 6674:Solar irradiance 6598: 6597: 6594:Electromagnetism 6534: 6527: 6520: 6511: 6510: 6505: 6493: 6382:, July 13, 2004. 6364:BGS Geomagnetism 6359:, March 8, 2011. 6324: 6298: 6258: 6239: 6210: 6208: 6207: 6187: 6159: 6149: 6139: 6129: 6112:(20): 11085–90. 6094: 6084: 6074: 6039: 6037: 6035: 6011: 5988: 5965: 5942: 5911: 5910: 5908: 5906: 5891: 5885: 5884: 5828: 5822: 5819: 5793: 5773: 5767: 5766: 5764: 5733: 5727: 5726: 5716: 5706: 5674: 5668: 5667: 5639: 5633: 5632: 5621: 5615: 5614: 5578: 5572: 5571: 5569: 5567: 5559:. United States 5553: 5547: 5546: 5544: 5543: 5534:. Archived from 5524: 5518: 5517: 5506: 5500: 5499: 5497: 5495: 5484: 5478: 5477: 5475: 5473: 5462: 5453: 5452: 5442: 5410: 5404: 5398: 5392: 5391: 5389: 5387: 5360: 5351: 5350: 5348: 5346: 5340: 5334:. Archived from 5318:(268): 373–388. 5309: 5300: 5294: 5293: 5291: 5289: 5279: 5268: 5262: 5261: 5259: 5257: 5238: 5232: 5231: 5185: 5179: 5178: 5145: 5139: 5138: 5136: 5135: 5130: 5121: 5115: 5114: 5104: 5070: 5064: 5063: 5053: 5013: 5007: 5001: 5000: 4996: 4985: 4974: 4973: 4945: 4939: 4938: 4935:10.1063/1.871485 4921:(5): 1421–1431. 4910: 4904: 4903: 4893: 4859: 4850: 4847: 4835: 4789: 4783: 4777: 4771: 4765: 4759: 4753: 4738: 4737: 4716: 4710: 4709: 4673: 4664: 4663: 4661: 4659: 4644: 4638: 4637: 4627: 4617: 4600:(9): 4192–4200. 4585: 4579: 4578: 4576: 4559:(3): 3.09–3.15. 4544: 4535: 4534: 4532: 4530: 4511: 4505: 4504: 4494: 4462: 4456: 4455: 4450:. Archived from 4443: 4437: 4436: 4426: 4394: 4388: 4387: 4342: 4336: 4335: 4333: 4301: 4295: 4294: 4292: 4260: 4254: 4253: 4251: 4249: 4214: 4208: 4202: 4196: 4190: 4184: 4183: 4165: 4159: 4158: 4148: 4130: 4098: 4092: 4091: 4089: 4087: 4073: 4067: 4066: 4038: 4032: 4019: 4008:10.1038/374687a0 3983: 3977: 3971: 3965: 3964: 3962: 3961: 3955: 3949:. Archived from 3933:(1–2): 146–157. 3924: 3915: 3909: 3908: 3879: 3873: 3872: 3870: 3868: 3849: 3840: 3839: 3813: 3785: 3779: 3778: 3776: 3774: 3769:on 16 March 2010 3754: 3748: 3747: 3745: 3743: 3728: 3722: 3721: 3719: 3717: 3708:. Archived from 3693: 3687: 3686: 3684: 3682: 3663: 3657: 3656: 3654: 3652: 3640: 3634: 3633: 3615: 3604: 3598: 3583: 3582: 3580: 3578: 3569:. Archived from 3558: 3547: 3546: 3544: 3542: 3527: 3521: 3520: 3484: 3478: 3477: 3475: 3474: 3458: 3452: 3451: 3431: 3425: 3424: 3404: 3398: 3397: 3377: 3371: 3370: 3368: 3366: 3351: 3345: 3344: 3342: 3340: 3329: 3323: 3322: 3320: 3319: 3304: 3298: 3297: 3295: 3293: 3281: 3272: 3271: 3269: 3267: 3262:on 21 March 2013 3251: 3245: 3244: 3242: 3241: 3227: 3221: 3215: 3190: 3189: 3187: 3186: 3176: 3170: 3169: 3151: 3145: 3144: 3126: 3120: 3119: 3101: 3095: 3094: 3076: 3063: 3050: 3044: 3043: 3015: 3009: 3008: 3006: 3004: 2985: 2979: 2978: 2958: 2952: 2951: 2949: 2939: 2922:(3): 1216–1230. 2906: 2900: 2899: 2897: 2895: 2883: 2877: 2876: 2865:10.1038/377203a0 2840: 2802:Magnetotellurics 2787:Geomagnetic jerk 2776: 2771: 2770: 2762: 2757: 2756: 2748: 2743: 2742: 2741: 2712:Magnetoreception 2639:(NATO), and the 2582: 2578: 2571: 2564: 2557: 2550: 2540: 2533: 2524: 2506: 2497: 2488: 2479: 2467: 2458: 2440: 2401: 2370: 2360: 2354: 2289:Magnetic anomaly 2222:Ørsted satellite 2184: 2146:kinematic dynamo 2136:Numerical models 2093: 2091: 2090: 2085: 2051: 2046:Laplace operator 2043: 2039: 2028: 2021: 2010: 2006: 2000: 1991: 1989: 1988: 1983: 1975: 1967: 1950: 1945: 1944: 1929: 1927: 1919: 1918: 1909: 1865:iron catastrophe 1777: 1675:can be found in 1536:Earth's interior 1488:Carrington Event 1357:magnetic equator 1330:Geomagnetic pole 1288: 1276: 1264: 1171:isodynamic chart 1137: 1131: 1125: 1119: 1103: 1089: 1069:magnetoreception 1038:mid-ocean ridges 939:Ellesmere Island 880:Earth's interior 843: 836: 829: 510:Electric machine 493:Magnetic circuit 455:Parallel circuit 445:Network analysis 410:Electric current 345:London equations 190:Triboelectricity 180:Potential energy 49: 39:Electromagnetism 30: 29: 21: 8601: 8600: 8596: 8595: 8594: 8592: 8591: 8590: 8566: 8565: 8564: 8559: 8541: 8508: 8492: 8449: 8440:Geologic record 8394: 8380:Plate tectonics 8370:Mineral physics 8350:Earth structure 8336: 8271: 8218: 8148: 8100: 8057: 8004: 7986: 7981: 7951: 7946: 7893: 7842: 7799: 7723: 7655: 7589: 7548: 7546:Magnetospherics 7543: 7513: 7508: 7471: 7462: 7446: 7397:Coriolis effect 7392:Chandler wobble 7384: 7378: 7354:Mineral physics 7317: 7296: 7291: 7261: 7256: 7219: 7210: 7184: 7180:Mineral physics 7113: 7075: 7022: 6996: 6982:Plate tectonics 6960: 6956:Palaeogeography 6927: 6903:Crystallography 6886: 6858: 6857: 6848: 6817: 6812: 6782: 6777: 6745: 6726:Egon Schweidler 6709: 6688: 6658: 6649:St. Elmo's fire 6627: 6589: 6543: 6538: 6484:. July 19, 2017 6481:Wayback Machine 6468:Wayback Machine 6457:Wayback Machine 6438:Wayback Machine 6344:Wayback Machine 6332: 6327: 6321: 6255: 6205: 6203: 6190: 6157: 6033: 6031: 6018: 6016:Further reading 6008: 5985: 5962: 5939: 5919: 5914: 5904: 5902: 5892: 5888: 5829: 5825: 5774: 5770: 5762:10.1038/458389a 5735: 5734: 5730: 5689:(14): 5708–13. 5675: 5671: 5640: 5636: 5623: 5622: 5618: 5579: 5575: 5565: 5563: 5555: 5554: 5550: 5541: 5539: 5526: 5525: 5521: 5508: 5507: 5503: 5493: 5491: 5486: 5485: 5481: 5471: 5469: 5464: 5463: 5456: 5425:(10): 787–804. 5411: 5407: 5399: 5395: 5385: 5383: 5381: 5361: 5354: 5344: 5342: 5341:on 16 July 2017 5338: 5307: 5301: 5297: 5287: 5285: 5277: 5269: 5265: 5255: 5253: 5241:Frey, Herbert. 5239: 5235: 5212:10.1038/416620a 5186: 5182: 5146: 5142: 5133: 5131: 5128: 5122: 5118: 5102:10.1038/439799a 5071: 5067: 5014: 5010: 4998: 4987: 4986: 4977: 4946: 4942: 4911: 4907: 4860: 4853: 4838: 4790: 4786: 4778: 4774: 4766: 4762: 4754: 4741: 4734: 4717: 4713: 4674: 4667: 4657: 4655: 4645: 4641: 4586: 4582: 4545: 4538: 4528: 4526: 4513: 4512: 4508: 4463: 4459: 4444: 4440: 4395: 4391: 4343: 4339: 4302: 4298: 4261: 4257: 4247: 4245: 4215: 4211: 4203: 4199: 4191: 4187: 4180: 4166: 4162: 4099: 4095: 4085: 4083: 4075: 4074: 4070: 4039: 4035: 4029:Wayback Machine 3984: 3980: 3972: 3968: 3959: 3957: 3953: 3922: 3916: 3912: 3905: 3880: 3876: 3866: 3864: 3863:on 25 July 2008 3851: 3850: 3843: 3811:10.1.1.560.5046 3786: 3782: 3772: 3770: 3755: 3751: 3741: 3739: 3730: 3729: 3725: 3715: 3713: 3694: 3690: 3680: 3678: 3677:on 21 June 2013 3665: 3664: 3660: 3650: 3648: 3641: 3637: 3630: 3616: 3607: 3603:, pages 126–141 3599: 3586: 3576: 3574: 3559: 3550: 3540: 3538: 3529: 3528: 3524: 3485: 3481: 3472: 3470: 3459: 3455: 3448: 3432: 3428: 3421: 3405: 3401: 3394: 3378: 3374: 3364: 3362: 3352: 3348: 3338: 3336: 3331: 3330: 3326: 3317: 3315: 3312:Cosmos Magazine 3306: 3305: 3301: 3291: 3289: 3282: 3275: 3265: 3263: 3252: 3248: 3239: 3237: 3229: 3228: 3224: 3216: 3193: 3184: 3182: 3178: 3177: 3173: 3166: 3152: 3148: 3141: 3127: 3123: 3116: 3102: 3098: 3091: 3077: 3066: 3060:Wayback Machine 3051: 3047: 3016: 3012: 3002: 3000: 2999:on 4 March 2016 2987: 2986: 2982: 2959: 2955: 2907: 2903: 2893: 2891: 2888:"The Geodynamo" 2884: 2880: 2841: 2834: 2830: 2817:Rings of Saturn 2812:Operation Argus 2772: 2765: 2758: 2751: 2744: 2739: 2737: 2734: 2714: 2708: 2589: 2580: 2577: 2573: 2570: 2566: 2563: 2559: 2558:) drops off as 2555: 2549: 2546: 2545:with radius as 2539: 2535: 2532: 2531: 2526: 2523: 2522: 2517: 2513: 2505: 2502: 2499: 2496: 2493: 2490: 2487: 2484: 2481: 2478: 2475: 2472: 2466: 2465: 2460: 2457: 2456: 2451: 2439: 2436: 2400: 2397: 2369: 2365: 2359: 2356: 2353: 2352: 2347: 2344: 2337: 2331: 2322: 2291: 2285: 2210: 2205: 2196: 2173: 2163: 2154:self-consistent 2138: 2119:Coriolis effect 2072: 2069: 2068: 2049: 2041: 2030: 2026: 2019: 2008: 2002: 1996: 1971: 1963: 1946: 1940: 1936: 1920: 1914: 1910: 1908: 1906: 1903: 1902: 1830: 1825: 1819: 1817:Physical origin 1800:heteroscedastic 1784: 1772: 1761: 1702:, particularly 1665: 1647: 1635:Steens Mountain 1630:and reversals. 1581: 1575: 1515: 1501: 1496: 1494:Time dependence 1379: 1373: 1332: 1326: 1313: 1299: 1292: 1289: 1280: 1277: 1268: 1265: 1256: 1247: 1235: 1229: 1217:isoclinic chart 1201: 1195: 1152: 1136: 1133: 1130: 1127: 1124: 1121: 1118: 1115: 1102: 1099: 1088: 1085: 1077: 1075:Characteristics 1014: 974:paleomagnetists 919:magnetic dipole 847: 818: 817: 633: 625: 624: 580: 570: 569: 525:Induction motor 495: 485: 484: 400:Current density 385: 375: 374: 365:Poynting vector 275: 273:Electrodynamics 265: 264: 260:Right-hand rule 225:Magnetic dipole 215:Biot–Savart law 205: 195: 194: 130:Electric dipole 125:Electric charge 100: 28: 23: 22: 15: 12: 11: 5: 8599: 8589: 8588: 8583: 8578: 8561: 8560: 8558: 8557: 8546: 8543: 8542: 8540: 8539: 8534: 8529: 8524: 8518: 8516: 8510: 8509: 8507: 8506: 8500: 8498: 8494: 8493: 8491: 8490: 8485: 8480: 8475: 8473:Atlantic Ocean 8470: 8465: 8459: 8457: 8451: 8450: 8448: 8447: 8442: 8437: 8436: 8435: 8425: 8420: 8415: 8410: 8404: 8402: 8396: 8395: 8393: 8392: 8387: 8382: 8377: 8372: 8367: 8362: 8357: 8355:Fluid dynamics 8352: 8346: 8344: 8338: 8337: 8335: 8334: 8329: 8327:Geopositioning 8324: 8322:Remote Sensing 8319: 8314: 8309: 8304: 8299: 8294: 8293: 8292: 8281: 8279: 8273: 8272: 8270: 8269: 8264: 8259: 8254: 8249: 8244: 8239: 8234: 8228: 8226: 8220: 8219: 8217: 8216: 8211: 8206: 8201: 8196: 8191: 8186: 8181: 8176: 8171: 8170: 8169: 8158: 8156: 8150: 8149: 8147: 8146: 8141: 8136: 8131: 8126: 8121: 8116: 8110: 8108: 8102: 8101: 8099: 8098: 8093: 8088: 8083: 8081:Climate change 8078: 8076:Energy balance 8073: 8071:Climate system 8067: 8065: 8059: 8058: 8056: 8055: 8050: 8045: 8040: 8035: 8030: 8025: 8020: 8014: 8012: 8006: 8005: 8003: 8002: 7997: 7991: 7988: 7987: 7980: 7979: 7972: 7965: 7957: 7948: 7947: 7945: 7944: 7943: 7942: 7937: 7932: 7927: 7917: 7912: 7907: 7901: 7899: 7898:Related topics 7895: 7894: 7892: 7891: 7886: 7881: 7876: 7871: 7866: 7861: 7856: 7850: 7848: 7844: 7843: 7841: 7840: 7835: 7830: 7829: 7828: 7818: 7813: 7807: 7805: 7801: 7800: 7798: 7797: 7790: 7785: 7780: 7773: 7764: 7759: 7754: 7749: 7744: 7735: 7731: 7729: 7725: 7724: 7722: 7721: 7716: 7711: 7706: 7701: 7696: 7691: 7686: 7681: 7676: 7671: 7669:Magnetic cloud 7665: 7663: 7657: 7656: 7654: 7653: 7648: 7643: 7638: 7633: 7628: 7623: 7618: 7613: 7608: 7603: 7597: 7595: 7591: 7590: 7588: 7587: 7582: 7577: 7572: 7567: 7562: 7556: 7554: 7550: 7549: 7542: 7541: 7534: 7527: 7519: 7510: 7509: 7507: 7506: 7494: 7482: 7467: 7464: 7463: 7461: 7460: 7454: 7452: 7448: 7447: 7445: 7444: 7439: 7434: 7429: 7424: 7419: 7414: 7409: 7404: 7399: 7394: 7388: 7386: 7380: 7379: 7377: 7376: 7374:Tectonophysics 7371: 7366: 7364:Paleomagnetism 7361: 7356: 7351: 7346: 7344:Geomathematics 7341: 7336: 7331: 7325: 7323: 7319: 7318: 7316: 7315: 7310: 7304: 7302: 7298: 7297: 7290: 7289: 7282: 7275: 7267: 7258: 7257: 7255: 7254: 7242: 7230: 7215: 7212: 7211: 7209: 7208: 7203: 7198: 7192: 7190: 7186: 7185: 7183: 7182: 7177: 7175:Mining geology 7172: 7167: 7162: 7157: 7152: 7147: 7142: 7137: 7132: 7127: 7121: 7119: 7115: 7114: 7112: 7111: 7109:Tectonophysics 7106: 7101: 7096: 7091: 7085: 7083: 7077: 7076: 7074: 7073: 7071:Geopositioning 7068: 7066:Remote sensing 7063: 7058: 7053: 7048: 7043: 7038: 7032: 7030: 7024: 7023: 7021: 7020: 7018:Marine geology 7015: 7010: 7004: 7002: 6998: 6997: 6995: 6994: 6989: 6984: 6979: 6974: 6968: 6966: 6962: 6961: 6959: 6958: 6953: 6948: 6943: 6937: 6935: 6929: 6928: 6926: 6925: 6920: 6915: 6910: 6905: 6900: 6898:Cosmochemistry 6894: 6892: 6888: 6887: 6885: 6884: 6879: 6874: 6868: 6866: 6860: 6859: 6851: 6849: 6847: 6846: 6841: 6836: 6831: 6825: 6823: 6819: 6818: 6811: 6810: 6803: 6796: 6788: 6779: 6778: 6776: 6775: 6763: 6750: 6747: 6746: 6744: 6743: 6738: 6736:George Simpson 6733: 6728: 6723: 6717: 6715: 6711: 6710: 6708: 6707: 6702: 6696: 6694: 6690: 6689: 6687: 6686: 6681: 6676: 6670: 6668: 6664: 6663: 6660: 6659: 6657: 6656: 6654:Ball lightning 6651: 6646: 6641: 6635: 6633: 6629: 6628: 6626: 6625: 6620: 6615: 6610: 6604: 6602: 6595: 6591: 6590: 6588: 6587: 6582: 6577: 6572: 6567: 6562: 6557: 6551: 6549: 6545: 6544: 6537: 6536: 6529: 6522: 6514: 6508: 6507: 6496:Chisholm, Hugh 6485: 6470: 6447: 6442: 6427: 6419: 6411: 6396:Magnetic Storm 6392: 6383: 6368: 6360: 6348: 6331: 6330:External links 6328: 6326: 6325: 6319: 6299: 6273:(2): 281–289. 6263:Wait, James R. 6259: 6253: 6240: 6222:(2): 221–225. 6211: 6188: 6150: 6095: 6057:(2): 646–648. 6040: 6019: 6017: 6014: 6013: 6012: 6006: 5989: 5983: 5975:Academic Press 5966: 5960: 5943: 5937: 5918: 5915: 5913: 5912: 5886: 5823: 5784:(6): 677–682. 5768: 5728: 5669: 5650:(8): 891–908. 5634: 5616: 5573: 5548: 5519: 5501: 5479: 5454: 5405: 5393: 5379: 5352: 5295: 5263: 5233: 5180: 5140: 5116: 5065: 5008: 4975: 4956:(1–3): 63–75. 4940: 4905: 4851: 4849: 4848: 4784: 4772: 4760: 4739: 4732: 4711: 4665: 4639: 4580: 4536: 4506: 4457: 4438: 4389: 4337: 4296: 4255: 4209: 4197: 4185: 4178: 4160: 4093: 4068: 4033: 3978: 3966: 3910: 3903: 3874: 3841: 3780: 3749: 3723: 3688: 3658: 3635: 3628: 3605: 3584: 3548: 3522: 3479: 3453: 3446: 3426: 3419: 3399: 3392: 3372: 3346: 3324: 3299: 3273: 3246: 3222: 3191: 3171: 3164: 3146: 3139: 3121: 3114: 3096: 3089: 3064: 3045: 3010: 2980: 2953: 2901: 2878: 2831: 2829: 2826: 2825: 2824: 2819: 2814: 2809: 2804: 2799: 2794: 2789: 2784: 2778: 2777: 2774:Physics portal 2763: 2749: 2733: 2730: 2710:Main article: 2707: 2704: 2696: 2695: 2685:developed the 2679: 2588: 2585: 2575: 2568: 2561: 2547: 2537: 2529: 2527: 2520: 2518: 2512: 2509: 2503: 2500: 2494: 2491: 2485: 2482: 2476: 2473: 2463: 2461: 2454: 2452: 2437: 2398: 2367: 2357: 2350: 2348: 2345: 2330: 2327: 2321: 2318: 2287:Main article: 2284: 2281: 2264:Commercially, 2209: 2206: 2204: 2201: 2195: 2192: 2162: 2159: 2137: 2134: 2082: 2079: 2076: 1993: 1992: 1981: 1978: 1974: 1970: 1966: 1962: 1959: 1956: 1953: 1949: 1943: 1939: 1935: 1932: 1926: 1923: 1917: 1913: 1829: 1826: 1821:Main article: 1818: 1815: 1783: 1780: 1760: 1757: 1693:Laschamp event 1661:Main article: 1646: 1643: 1612:westward drift 1577:Main article: 1574: 1571: 1512:magnetic storm 1500: 1497: 1495: 1492: 1372: 1369: 1328:Main article: 1325: 1324:Magnetic poles 1322: 1298: 1295: 1294: 1293: 1290: 1283: 1281: 1278: 1271: 1269: 1266: 1259: 1248: 1246: 1243: 1239:celestial pole 1231:Main article: 1228: 1225: 1197:Main article: 1194: 1191: 1151: 1148: 1134: 1128: 1122: 1116: 1100: 1086: 1076: 1073: 1013: 1010: 950:magnetic poles 906:and nickel in 876:magnetic field 849: 848: 846: 845: 838: 831: 823: 820: 819: 816: 815: 810: 805: 800: 795: 790: 785: 780: 775: 770: 765: 760: 755: 750: 745: 740: 735: 730: 725: 720: 715: 710: 705: 700: 695: 690: 685: 680: 675: 670: 665: 660: 655: 650: 645: 640: 634: 631: 630: 627: 626: 623: 622: 617: 612: 607: 602: 600:Four-potential 597: 592: 587: 581: 576: 575: 572: 571: 568: 567: 562: 557: 552: 547: 542: 537: 532: 527: 522: 517: 515:Electric motor 512: 507: 502: 496: 491: 490: 487: 486: 483: 482: 477: 472: 470:Series circuit 467: 462: 457: 452: 447: 442: 440:Kirchhoff laws 437: 432: 427: 422: 417: 412: 407: 405:Direct current 402: 397: 392: 386: 381: 380: 377: 376: 373: 372: 367: 362: 360:Maxwell tensor 357: 352: 347: 342: 337: 332: 330:Larmor formula 327: 322: 317: 312: 307: 302: 297: 292: 287: 282: 280:Bremsstrahlung 276: 271: 270: 267: 266: 263: 262: 257: 252: 247: 242: 237: 232: 230:Magnetic field 227: 222: 217: 212: 206: 203:Magnetostatics 201: 200: 197: 196: 193: 192: 187: 182: 177: 172: 167: 162: 157: 152: 147: 142: 137: 135:Electric field 132: 127: 122: 117: 112: 107: 105:Charge density 101: 98:Electrostatics 96: 95: 92: 91: 90: 89: 84: 79: 74: 69: 64: 59: 51: 50: 42: 41: 35: 34: 33:Articles about 26: 9: 6: 4: 3: 2: 8598: 8587: 8584: 8582: 8579: 8577: 8574: 8573: 8571: 8556: 8548: 8547: 8544: 8538: 8535: 8533: 8530: 8528: 8525: 8523: 8520: 8519: 8517: 8515: 8511: 8505: 8502: 8501: 8499: 8495: 8489: 8486: 8484: 8483:Pacific Ocean 8481: 8479: 8476: 8474: 8471: 8469: 8466: 8464: 8461: 8460: 8458: 8456: 8452: 8446: 8443: 8441: 8438: 8434: 8431: 8430: 8429: 8426: 8424: 8421: 8419: 8416: 8414: 8413:Earth science 8411: 8409: 8406: 8405: 8403: 8401: 8397: 8391: 8388: 8386: 8383: 8381: 8378: 8376: 8373: 8371: 8368: 8366: 8365:Magnetosphere 8363: 8361: 8358: 8356: 8353: 8351: 8348: 8347: 8345: 8343: 8339: 8333: 8332:Virtual globe 8330: 8328: 8325: 8323: 8320: 8318: 8315: 8313: 8310: 8308: 8305: 8303: 8300: 8298: 8297:Earth's orbit 8295: 8291: 8288: 8287: 8286: 8283: 8282: 8280: 8278: 8274: 8268: 8265: 8263: 8260: 8258: 8255: 8253: 8250: 8248: 8245: 8243: 8240: 8238: 8235: 8233: 8230: 8229: 8227: 8225: 8221: 8215: 8212: 8210: 8207: 8205: 8204:World history 8202: 8200: 8197: 8195: 8194:World economy 8192: 8190: 8187: 8185: 8182: 8180: 8177: 8175: 8172: 8168: 8165: 8164: 8163: 8160: 8159: 8157: 8155: 8151: 8145: 8144:South America 8142: 8140: 8139:North America 8137: 8135: 8132: 8130: 8127: 8125: 8122: 8120: 8117: 8115: 8112: 8111: 8109: 8107: 8103: 8097: 8094: 8092: 8089: 8087: 8084: 8082: 8079: 8077: 8074: 8072: 8069: 8068: 8066: 8064: 8060: 8054: 8051: 8049: 8046: 8044: 8041: 8039: 8036: 8034: 8031: 8029: 8026: 8024: 8021: 8019: 8016: 8015: 8013: 8011: 8007: 8001: 7998: 7996: 7993: 7992: 7989: 7985: 7978: 7973: 7971: 7966: 7964: 7959: 7958: 7955: 7941: 7938: 7936: 7933: 7931: 7928: 7926: 7923: 7922: 7921: 7918: 7916: 7913: 7911: 7908: 7906: 7903: 7902: 7900: 7896: 7890: 7887: 7885: 7882: 7880: 7877: 7875: 7872: 7870: 7867: 7865: 7862: 7860: 7857: 7855: 7852: 7851: 7849: 7845: 7839: 7836: 7834: 7831: 7827: 7824: 7823: 7822: 7819: 7817: 7814: 7812: 7809: 7808: 7806: 7802: 7796: 7795: 7791: 7789: 7786: 7784: 7781: 7779: 7778: 7774: 7768: 7765: 7763: 7760: 7758: 7755: 7753: 7750: 7748: 7745: 7739: 7736: 7733: 7732: 7730: 7726: 7720: 7719:Space weather 7717: 7715: 7714:Space climate 7712: 7710: 7707: 7705: 7702: 7700: 7697: 7695: 7692: 7690: 7687: 7685: 7682: 7680: 7677: 7675: 7672: 7670: 7667: 7666: 7664: 7662: 7658: 7652: 7649: 7647: 7644: 7642: 7639: 7637: 7634: 7632: 7629: 7627: 7626:Magnetosphere 7624: 7622: 7621:Magnetosheath 7619: 7617: 7614: 7612: 7609: 7607: 7604: 7602: 7599: 7598: 7596: 7592: 7586: 7583: 7581: 7578: 7576: 7573: 7571: 7568: 7566: 7563: 7561: 7558: 7557: 7555: 7551: 7547: 7540: 7535: 7533: 7528: 7526: 7521: 7520: 7517: 7505: 7504: 7495: 7493: 7492: 7483: 7481: 7480: 7475: 7469: 7468: 7465: 7459: 7456: 7455: 7453: 7449: 7443: 7440: 7438: 7435: 7433: 7430: 7428: 7425: 7423: 7420: 7418: 7415: 7413: 7410: 7408: 7405: 7403: 7400: 7398: 7395: 7393: 7390: 7389: 7387: 7381: 7375: 7372: 7370: 7367: 7365: 7362: 7360: 7357: 7355: 7352: 7350: 7347: 7345: 7342: 7340: 7337: 7335: 7332: 7330: 7327: 7326: 7324: 7320: 7314: 7313:Geophysicists 7311: 7309: 7306: 7305: 7303: 7299: 7295: 7288: 7283: 7281: 7276: 7274: 7269: 7268: 7265: 7253: 7252: 7243: 7241: 7240: 7231: 7229: 7228: 7223: 7217: 7216: 7213: 7207: 7206:Volcanologist 7204: 7202: 7199: 7197: 7194: 7193: 7191: 7187: 7181: 7178: 7176: 7173: 7171: 7168: 7166: 7163: 7161: 7158: 7156: 7153: 7151: 7148: 7146: 7143: 7141: 7138: 7136: 7133: 7131: 7128: 7126: 7123: 7122: 7120: 7116: 7110: 7107: 7105: 7102: 7100: 7097: 7095: 7092: 7090: 7087: 7086: 7084: 7082: 7078: 7072: 7069: 7067: 7064: 7062: 7059: 7057: 7054: 7052: 7049: 7047: 7044: 7042: 7041:Earth's orbit 7039: 7037: 7034: 7033: 7031: 7029: 7025: 7019: 7016: 7014: 7011: 7009: 7006: 7005: 7003: 6999: 6993: 6990: 6988: 6987:Geomorphology 6985: 6983: 6980: 6978: 6975: 6973: 6970: 6969: 6967: 6965:Dynamic Earth 6963: 6957: 6954: 6952: 6949: 6947: 6944: 6942: 6939: 6938: 6936: 6934: 6930: 6924: 6923:Sedimentology 6921: 6919: 6916: 6914: 6911: 6909: 6906: 6904: 6901: 6899: 6896: 6895: 6893: 6889: 6883: 6880: 6878: 6875: 6873: 6872:Geochronology 6870: 6869: 6867: 6865: 6861: 6855: 6845: 6842: 6840: 6837: 6835: 6832: 6830: 6827: 6826: 6824: 6820: 6816: 6809: 6804: 6802: 6797: 6795: 6790: 6789: 6786: 6774: 6773: 6764: 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6217: 6212: 6202:on 2010-09-08 6201: 6197: 6193: 6189: 6185: 6181: 6177: 6173: 6169: 6165: 6164: 6163:Physics Today 6156: 6151: 6147: 6143: 6138: 6133: 6128: 6123: 6119: 6115: 6111: 6107: 6106: 6101: 6096: 6092: 6088: 6083: 6078: 6073: 6068: 6064: 6060: 6056: 6052: 6051: 6046: 6041: 6030: 6026: 6021: 6020: 6009: 6003: 5999: 5995: 5990: 5986: 5980: 5976: 5972: 5967: 5963: 5957: 5953: 5949: 5944: 5940: 5934: 5930: 5926: 5921: 5920: 5901: 5900:IEEE Spectrum 5897: 5890: 5882: 5878: 5874: 5870: 5866: 5862: 5858: 5854: 5850: 5846: 5842: 5838: 5834: 5827: 5821: 5817: 5813: 5809: 5805: 5801: 5797: 5792: 5787: 5783: 5779: 5772: 5763: 5758: 5754: 5750: 5746: 5742: 5738: 5732: 5724: 5720: 5715: 5710: 5705: 5700: 5696: 5692: 5688: 5684: 5680: 5673: 5665: 5661: 5657: 5653: 5649: 5645: 5638: 5630: 5626: 5620: 5612: 5608: 5604: 5600: 5596: 5592: 5588: 5584: 5577: 5562: 5558: 5552: 5538:on 2021-12-09 5537: 5533: 5529: 5523: 5515: 5511: 5505: 5489: 5483: 5467: 5461: 5459: 5450: 5446: 5441: 5436: 5432: 5428: 5424: 5420: 5416: 5409: 5402: 5401:Campbell 2003 5397: 5382: 5376: 5372: 5371: 5366: 5359: 5357: 5337: 5333: 5329: 5325: 5321: 5317: 5313: 5306: 5299: 5283: 5276: 5275: 5267: 5252: 5248: 5244: 5237: 5229: 5225: 5221: 5217: 5213: 5209: 5205: 5201: 5197: 5193: 5192: 5184: 5176: 5172: 5168: 5164: 5160: 5156: 5155: 5150: 5144: 5127: 5120: 5112: 5108: 5103: 5098: 5094: 5090: 5086: 5082: 5081: 5076: 5069: 5061: 5057: 5052: 5047: 5043: 5039: 5035: 5031: 5027: 5023: 5019: 5012: 5005: 5004:public domain 4994: 4990: 4984: 4982: 4980: 4971: 4967: 4963: 4959: 4955: 4951: 4944: 4936: 4932: 4928: 4924: 4920: 4916: 4909: 4901: 4897: 4892: 4887: 4883: 4879: 4875: 4871: 4870: 4865: 4858: 4856: 4845: 4841: 4837: 4836: 4833: 4829: 4825: 4821: 4817: 4813: 4809: 4805: 4801: 4797: 4796: 4788: 4781: 4776: 4769: 4764: 4757: 4752: 4750: 4748: 4746: 4744: 4735: 4729: 4725: 4721: 4715: 4707: 4703: 4699: 4695: 4691: 4687: 4683: 4679: 4672: 4670: 4654: 4650: 4643: 4635: 4631: 4626: 4621: 4616: 4611: 4607: 4603: 4599: 4595: 4591: 4584: 4575: 4570: 4566: 4562: 4558: 4554: 4550: 4543: 4541: 4524: 4520: 4516: 4510: 4502: 4498: 4493: 4488: 4484: 4480: 4476: 4472: 4468: 4461: 4453: 4449: 4442: 4434: 4430: 4425: 4420: 4416: 4412: 4408: 4404: 4400: 4393: 4385: 4381: 4377: 4373: 4369: 4365: 4361: 4357: 4353: 4349: 4341: 4332: 4327: 4323: 4319: 4315: 4311: 4307: 4300: 4291: 4286: 4282: 4278: 4274: 4270: 4266: 4259: 4244: 4240: 4236: 4232: 4228: 4224: 4220: 4213: 4206: 4201: 4194: 4189: 4181: 4175: 4171: 4164: 4156: 4152: 4147: 4142: 4138: 4134: 4129: 4124: 4120: 4116: 4112: 4108: 4104: 4097: 4082: 4078: 4072: 4064: 4060: 4056: 4052: 4048: 4044: 4037: 4030: 4026: 4023: 4017: 4013: 4009: 4005: 4001: 3997: 3993: 3989: 3982: 3975: 3970: 3956:on 2013-10-23 3952: 3948: 3944: 3940: 3936: 3932: 3928: 3921: 3914: 3906: 3900: 3896: 3892: 3888: 3884: 3878: 3862: 3858: 3854: 3848: 3846: 3837: 3833: 3829: 3825: 3821: 3817: 3812: 3807: 3803: 3799: 3795: 3791: 3784: 3768: 3764: 3760: 3753: 3737: 3733: 3732:"The K-index" 3727: 3711: 3707: 3703: 3699: 3692: 3676: 3672: 3668: 3662: 3646: 3639: 3631: 3625: 3621: 3614: 3612: 3610: 3602: 3597: 3595: 3593: 3591: 3589: 3572: 3568: 3564: 3557: 3555: 3553: 3536: 3532: 3526: 3518: 3514: 3510: 3506: 3502: 3498: 3494: 3490: 3483: 3468: 3464: 3457: 3449: 3443: 3439: 3438: 3430: 3422: 3416: 3412: 3411: 3403: 3395: 3389: 3385: 3384: 3376: 3361: 3357: 3350: 3334: 3328: 3313: 3309: 3303: 3287: 3280: 3278: 3261: 3257: 3250: 3236: 3232: 3226: 3219: 3214: 3212: 3210: 3208: 3206: 3204: 3202: 3200: 3198: 3196: 3181: 3175: 3167: 3161: 3157: 3150: 3142: 3136: 3132: 3125: 3117: 3111: 3107: 3100: 3092: 3086: 3082: 3075: 3073: 3071: 3069: 3061: 3057: 3054: 3049: 3041: 3037: 3033: 3029: 3025: 3021: 3014: 2998: 2994: 2993:Cosmos Online 2990: 2984: 2976: 2972: 2968: 2964: 2957: 2948: 2943: 2938: 2933: 2929: 2925: 2921: 2917: 2913: 2905: 2889: 2882: 2874: 2870: 2866: 2862: 2858: 2854: 2850: 2846: 2839: 2837: 2832: 2823: 2820: 2818: 2815: 2813: 2810: 2808: 2805: 2803: 2800: 2798: 2795: 2793: 2790: 2788: 2785: 2783: 2780: 2779: 2775: 2769: 2764: 2761: 2755: 2750: 2747: 2736: 2729: 2725: 2723: 2719: 2713: 2703: 2701: 2700:Paleomagnetic 2692: 2688: 2684: 2680: 2677: 2673: 2669: 2665: 2661: 2657: 2653: 2652: 2651: 2649: 2644: 2642: 2638: 2634: 2630: 2626: 2622: 2618: 2614: 2609: 2606: 2602: 2598: 2594: 2587:Global models 2584: 2552: 2544: 2541:and one that 2508: 2469: 2450: 2446: 2445: 2434: 2430: 2425: 2423: 2422: 2417: 2416: 2411: 2410: 2405: 2396: 2392: 2391: 2386: 2377: 2363: 2362:great circles 2341: 2336: 2326: 2317: 2315: 2311: 2307: 2303: 2302:Magnetometers 2295: 2290: 2280: 2278: 2274: 2270: 2267: 2262: 2260: 2256: 2252: 2247: 2245: 2240: 2238: 2234: 2230: 2225: 2223: 2219: 2215: 2200: 2191: 2171: 2169: 2158: 2155: 2150: 2147: 2143: 2133: 2130: 2127: 2126:T-Tauri phase 2122: 2120: 2116: 2112: 2108: 2103: 2101: 2097: 2077: 2074: 2065: 2062: 2057: 2055: 2054:curl operator 2047: 2038: 2034: 2025: 2018: 2014: 2005: 1999: 1979: 1968: 1957: 1951: 1941: 1933: 1930: 1924: 1901: 1900: 1899: 1897: 1893: 1889: 1888:Lorentz force 1885: 1884:Faraday's law 1881: 1877: 1872: 1870: 1866: 1862: 1858: 1854: 1850: 1846: 1837: 1833: 1824: 1823:Dynamo theory 1814: 1812: 1808: 1803: 1801: 1796: 1788: 1779: 1775: 1770: 1766: 1756: 1754: 1750: 1746: 1742: 1740: 1736: 1731: 1729: 1725: 1721: 1717: 1713: 1709: 1705: 1701: 1696: 1694: 1690: 1686: 1682: 1678: 1674: 1670: 1664: 1656: 1651: 1642: 1638: 1636: 1631: 1629: 1625: 1621: 1616: 1613: 1608: 1604: 1602: 1593: 1585: 1580: 1570: 1568: 1564: 1559: 1554: 1552: 1548: 1543: 1541: 1537: 1533: 1525: 1522: 1518: 1513: 1509: 1505: 1491: 1489: 1485: 1481: 1477: 1473: 1472:space weather 1468: 1466: 1462: 1458: 1452: 1450: 1446: 1442: 1437: 1435: 1431: 1427: 1423: 1418: 1416: 1412: 1408: 1404: 1399: 1397: 1393: 1383: 1378: 1377:Magnetosphere 1371:Magnetosphere 1368: 1366: 1360: 1358: 1355:in 2001. The 1354: 1350: 1344: 1336: 1331: 1321: 1319: 1312: 1303: 1287: 1282: 1275: 1270: 1263: 1258: 1257: 1255: 1253: 1242: 1240: 1234: 1224: 1222: 1218: 1213: 1211: 1206: 1200: 1190: 1187: 1182: 1180: 1176: 1172: 1167: 1165: 1161: 1157: 1143: 1139: 1113: 1109: 1108: 1097: 1093: 1083: 1072: 1070: 1066: 1061: 1059: 1055: 1051: 1047: 1043: 1039: 1035: 1031: 1030:igneous rocks 1026: 1024: 1020: 1009: 1007: 1003: 999: 995: 991: 987: 983: 979: 978:magnetosphere 975: 971: 967: 963: 959: 955: 951: 946: 944: 940: 936: 932: 928: 924: 920: 915: 913: 909: 905: 901: 897: 893: 889: 885: 881: 877: 873: 869: 862: 857: 853: 844: 839: 837: 832: 830: 825: 824: 822: 821: 814: 811: 809: 806: 804: 801: 799: 796: 794: 791: 789: 786: 784: 781: 779: 776: 774: 771: 769: 766: 764: 761: 759: 756: 754: 751: 749: 746: 744: 741: 739: 736: 734: 731: 729: 726: 724: 721: 719: 716: 714: 711: 709: 706: 704: 701: 699: 696: 694: 691: 689: 686: 684: 681: 679: 676: 674: 671: 669: 666: 664: 661: 659: 656: 654: 651: 649: 646: 644: 641: 639: 636: 635: 629: 628: 621: 618: 616: 613: 611: 608: 606: 603: 601: 598: 596: 593: 591: 588: 586: 583: 582: 579: 574: 573: 566: 563: 561: 558: 556: 553: 551: 548: 546: 543: 541: 538: 536: 533: 531: 528: 526: 523: 521: 518: 516: 513: 511: 508: 506: 503: 501: 498: 497: 494: 489: 488: 481: 478: 476: 473: 471: 468: 466: 463: 461: 458: 456: 453: 451: 448: 446: 443: 441: 438: 436: 435:Joule heating 433: 431: 428: 426: 423: 421: 418: 416: 413: 411: 408: 406: 403: 401: 398: 396: 393: 391: 388: 387: 384: 379: 378: 371: 368: 366: 363: 361: 358: 356: 353: 351: 350:Lorentz force 348: 346: 343: 341: 338: 336: 333: 331: 328: 326: 323: 321: 318: 316: 313: 311: 308: 306: 303: 301: 298: 296: 293: 291: 288: 286: 283: 281: 278: 277: 274: 269: 268: 261: 258: 256: 253: 251: 250:Magnetization 248: 246: 243: 241: 238: 236: 235:Magnetic flux 233: 231: 228: 226: 223: 221: 218: 216: 213: 211: 208: 207: 204: 199: 198: 191: 188: 186: 183: 181: 178: 176: 173: 171: 168: 166: 163: 161: 158: 156: 153: 151: 148: 146: 143: 141: 140:Electric flux 138: 136: 133: 131: 128: 126: 123: 121: 118: 116: 113: 111: 108: 106: 103: 102: 99: 94: 93: 88: 85: 83: 80: 78: 77:Computational 75: 73: 70: 68: 65: 63: 60: 58: 55: 54: 53: 52: 48: 44: 43: 40: 37: 36: 32: 31: 19: 8576:Geomagnetism 8537:Solar System 8488:Oceanography 8478:Indian Ocean 8468:Arctic Ocean 8408:Age of Earth 8360:Geomagnetism 8359: 8043:Thermosphere 8033:Stratosphere 7920:Ring systems 7915:Lunar swirls 7792: 7775: 7646:Ring current 7641:Plasmasphere 7616:Magnetopause 7569: 7501: 7489: 7470: 7437:Seismic wave 7406: 7339:Geomagnetism 7338: 7249: 7237: 7218: 7118:Applications 7089:Geomagnetism 7013:Hydrogeology 6946:Paleontology 6941:Stratigraphy 6908:Geochemistry 6770: 6758: 6731:Nikola Tesla 6693:Applications 6584: 6499: 6472: 6429: 6421: 6413: 6407: 6394: 6386: 6385:John Roach, 6377: 6371: 6362: 6350: 6335: 6306: 6303:Walt, Martin 6270: 6266: 6244: 6219: 6215: 6204:. Retrieved 6200:the original 6195: 6170:(2): 31–37. 6167: 6161: 6109: 6103: 6054: 6048: 6032:. Retrieved 6029:Science News 6028: 5993: 5970: 5947: 5924: 5903:. Retrieved 5899: 5889: 5840: 5836: 5826: 5781: 5777: 5771: 5744: 5740: 5731: 5686: 5682: 5672: 5647: 5643: 5637: 5628: 5619: 5586: 5582: 5576: 5564:. Retrieved 5551: 5540:. Retrieved 5536:the original 5531: 5522: 5513: 5504: 5492:. Retrieved 5482: 5470:. Retrieved 5422: 5418: 5408: 5403:, p. 1. 5396: 5384:. Retrieved 5369: 5343:. Retrieved 5336:the original 5315: 5311: 5298: 5286:. Retrieved 5284:. p. 66 5273: 5266: 5254:. Retrieved 5246: 5236: 5195: 5189: 5183: 5158: 5152: 5143: 5132:. Retrieved 5119: 5084: 5078: 5068: 5025: 5021: 5011: 4992: 4953: 4949: 4943: 4918: 4914: 4908: 4873: 4867: 4843: 4799: 4793: 4787: 4782:, Chapter 11 4775: 4770:, Chapter 10 4763: 4723: 4714: 4681: 4677: 4656:. Retrieved 4653:ScienceDaily 4652: 4642: 4597: 4593: 4583: 4556: 4552: 4527:. 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