Earth's magnetic field

1825: 2757: 2305:. 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. 2729: 1275: 1263: 2329: 1573: 1791:(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. 1639: 1131: 1324: 1581: 1251: 8034: 1730:, 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. 1776: 1291: 7463: 2743: 845: 36: 2568:, 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 1493: 7211: 1371: 8530: 7475: 7223: 6744: 1309:, 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. 6843: 2283: 2365: 2163: 7235: 7487: 6756: 4988: 2102:. 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 1336:

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

1626:, 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. 2376:. 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 2166: 2709:. 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 2165: 1230:. 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). 2170: 2169: 2164: 2716:

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.;

2436:. 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 1304:

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

2091:. 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. 1629:

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.

1979: 2168: 852:'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. 2133:(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 1443:

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

2087:, 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 2313:

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).

1463:, 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 2659:. 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 1425:). 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. 1196:

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).

1417:. 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 1893: 2052:

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).

2167: 1440:. 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. 1352:

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

1151:(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 926:

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.

2496:– 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. 1821:

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

1523:) 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 2081: 4436: 2540:. 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. 1715:. 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 1592:. 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. 1471:

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;

2228:. Such observatories can measure and forecast magnetic conditions such as magnetic storms that sometimes affect communications, electric power, and other human activities. 1394:, 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 1448:. 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 1390:

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.

1848:, 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 ( 2581: 593: 3244: 1294:

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.

3908: 3551: 1844:. 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 4937:

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".

3747: 2977: 2612:. This model truncates at degree 12 (168 coefficients) with an approximate spatial resolution of 3,000 kilometers. It is the model used by the 1744:, a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies. 941:

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".

1299: 1010:, resulting from scavenging of ions by the solar wind, indicate that the dissipation of the magnetic field of Mars caused a near total loss 7809: 3777:

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.

1060:, various other organisms, ranging from some types of bacteria to pigeons, use the Earth's magnetic field for orientation and navigation. 8490: 7273: 6441: 2832:

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).

1974:{\displaystyle {\frac {\partial \mathbf {B} }{\partial t}}=\eta \nabla ^{2}\mathbf {B} +\nabla \times (\mathbf {u} \times \mathbf {B} ),} 6489: 1017:

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.

1767:. In 2024 researchers published evidence from Greenland for the existence of the magnetic field as early as 3,700 million years ago. 1607:

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

4440: 1646:. Dark areas denote periods where the polarity matches today's polarity, light areas denote periods where that polarity is reversed. 1479:, occurred in 1859. It induced currents strong enough to disrupt telegraph lines, and aurorae were reported as far south as Hawaii. 6760: 6403: 4208:"Ice Age Polarity Reversal Was Global Event: Extremely Brief Reversal of Geomagnetic Field, Climate Variability, and Super Volcano" 1860:

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

608: 5884: 3296: 2235:, with over 100 interlinked geomagnetic observatories around the world, has been recording the Earth's magnetic field since 1991. 4503: 2629: 1538:

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

2110:, caused by the overall planetary rotation, tends to organize the flow into rolls aligned along the north–south polar axis. 1722:

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

8564: 8495: 4295:"Evidence for a 3.45-billion-year-old magnetic remanence: Hints of an ancient geodynamo from conglomerates of South Africa" 2617: 458: 6013: 3344: 2613: 1170:

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

3720: 2625: 4388:"Possible Eoarchean Records of the Geomagnetic Field Preserved in the Isua Supracrustal Belt, Southern West Greenland" 1824: 7826: 7755: 6794: 5631:

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

2588:(IGRF). It is updated every five years. The 11th-generation model, IGRF11, was developed using data from satellites ( 60: 5572:

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

8236: 7963: 7266: 6345: 5270: 2656: 2621: 2012: 243: 3321: 8065: 6724: 822: 588: 65: 6224: 3663: 7682: 7624: 7518: 6606: 2395:ℓ. Each harmonic is equivalent to a particular arrangement of magnetic charges at the center of the Earth. A 2159:

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

1880: 1872: 1673: 1567: 1384: 603: 308: 2391:. The function of latitude is zero along zero or more latitude circles; this plus the order is equal to the 1712: 1472: 945:

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

8334: 7847: 7687: 7337: 7259: 7049: 6356:. Information on monitoring and modeling the geomagnetic field. British Geological Survey, August 2005. 6299: 5917: 5140:; Le Mouel, Jean Louis (1988). "Time Variations of the Earth's Magnetic Field: From Daily to Secular". 4781:

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

2059: 1875:); and the electric and magnetic fields exert a force on the charges that are flowing in currents (the 1109:) of the field is proportional to the force it exerts on a magnet. Another common representation is in 261: 6479: 2469:, gives the contribution of an isolated magnetic charge, so it is zero. The next three coefficients – 1668:, sediment cores taken from the ocean floors, and seafloor magnetic anomalies. Reversals occur nearly 1615:. The records typically include long periods of small change with occasional large changes reflecting 1274: 1262: 6832: 6392: 2609: 2432: 2302: 2243: 2221: 1849: 1572: 1520: 815: 776: 303: 293: 233: 228: 168: 5324: 4638:"Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows" 4010: 3799: 2664: 2286:

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

8141: 8055: 7857: 7639: 7619: 7511: 7390: 5114: 1508:: map showing locations of observatories and contour lines giving horizontal magnetic intensity in 1418: 313: 3219: 899:: these convection currents are caused by heat escaping from the core, a natural process called a 746: 248: 16:

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

7867: 7740: 7735: 7548: 7347: 6529: 6143: 4637: 4207: 2951: 2675: 2225: 2005: 1174: 626: 153: 143: 138: 6448:

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

5809: 751: 721: 7862: 7852: 7692: 6709: 6611: 5822:"Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird" 3794: 2810: 2785: 2413:

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

2294: 2265: 2247: 1757: 1700: 1528: 1167: 923: 919: 573: 343: 118: 6438: 3424: 3397: 3370: 2360:

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

1867:. The magnetic field is generated by a feedback loop: current loops generate magnetic fields ( 1250: 8554: 8108: 7662: 7301: 7296: 7128: 6787: 6688: 6672: 6568: 6558: 4857: 2734: 1841: 1837: 1760:

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

1616: 1468: 1022: 896: 671: 358: 348: 298: 288: 5524: 5419: 4553: 4223: 4043: 3927: 2589: 2210: 2155:

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

8269: 8221: 7993: 7697: 6263: 6212: 6188: 6160: 6102: 6047: 5833: 5737: 5679: 5579: 5415: 5308: 5188: 5151: 5077: 5018: 4946: 4911: 4866: 4792: 4674: 4590: 4549: 4467: 4399: 4344: 4306: 4293:

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

4265: 4219: 4103: 4039: 3984: 3923: 3786: 3485: 3016: 2912: 2841: 2780: 2601: 2368:

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

2202: 2130: 2001: 1845: 1833: 1669: 1651: 1555: 1356:

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

1240: 1221: 1053: 946: 796: 696: 661: 413: 278: 178: 163: 98: 1711:, the direction of the field is "frozen" in small minerals as they cool, giving rise to a 35: 8: 8559: 8412: 8369: 8203: 8146: 7988: 7980: 7956: 7479: 7405: 7189: 7153: 7123: 6870: 6822: 6553: 6548: 3871: 3476:

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

3451: 2373: 2323: 1741: 1524: 1353: 1193: 1152: 1034: 994: 954: 950: 911: 756: 736: 731: 538: 523: 408: 378: 273: 203: 6267: 6216: 6164: 6106: 6051: 5837: 5741: 5683: 5668:"Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants" 5583: 5402:

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

5312: 5192: 5163: 5155: 5081: 5022: 4950: 4915: 4870: 4796: 4678: 4594: 4471: 4403: 4348: 4310: 4269: 4107: 3988: 3909:"Eastward and westward drift of the Earth's magnetic field for the last three millennia" 3790: 3489: 3020: 2916: 2845: 2328: 8281: 7750: 7322: 7143: 7082: 7034: 6960: 6921: 6852: 6827: 6817: 6637: 6632: 6563: 6367: 6279: 5865: 5800: 5774: 5702: 5667: 5595: 5433: 5212: 5137: 5039: 5006: 4884: 4816: 4368: 4134: 4091: 4000: 3820: 3812: 3656:"Shields Up! A breeze of interstellar helium atoms is blowing through the solar system" 3501: 2857: 2679: 2639:

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

2636: 2042: 1733: 1680:, takes the dipole axis across the equator and then back to the original polarity. The 1588:

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

1449: 1042: 1030: 1011: 888: 868: 631: 371: 173: 133: 6234:

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

5231: 4613: 4578: 4092:"Rapid geomagnetic changes inferred from Earth observations and numerical simulations" 3874:(2007). "Dipole Moment Variation". In Gubbins, David; Herrero-Bervera, Emilio (eds.). 3274: 453: 8500: 8477: 8397: 8364: 7782: 7765: 7726: 7672: 7589: 7467: 7415: 7239: 7133: 6596: 6325: 6303: 6237: 6130: 6125: 6088: 6075: 6070: 6033: 5990: 5967: 5944: 5921: 5857: 5849: 5792: 5707: 5648: 5363: 5353: 5204: 5095: 5044: 4958: 4808: 4716: 4690: 4618: 4562: 4537: 4485: 4417: 4360: 4162: 4139: 4121: 3887: 3612: 3505: 3430: 3403: 3376: 3148: 3123: 3098: 3073: 2925: 2900: 2748: 2593: 2397: 2260:

companies also use magnetic detectors to identify naturally occurring anomalies from

2217: 1684:

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

1657: 1638: 1464: 1337: 1323: 1130: 691: 6419: 6283: 6254:(1954). "On the relation between telluric currents and the earth's magnetic field". 5804: 5599: 5357: 4888: 4372: 4066:"Simulations show magnetic field can change 10 times faster than previously thought" 3824: 2238:

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

1580: 8523: 8518: 8424: 8291: 8276: 8153: 8133: 8075: 7928: 7913: 7776: 7420: 7410: 7227: 7148: 7118: 7044: 7029: 6939: 6780: 6693: 6662: 6601: 6271: 6220: 6168: 6120: 6110: 6065: 6055: 5869: 5841: 5784: 5745: 5697: 5687: 5640: 5587: 5476: 5423: 5320: 5316: 5216: 5196: 5179: 5159: 5085: 5068: 5034: 5026: 4954: 4919: 4874: 4820: 4800: 4783: 4682: 4608: 4598: 4557: 4511: 4475: 4407: 4352: 4314: 4273: 4227: 4129: 4111: 4047: 4004: 3992: 3931: 3879: 3804: 3698: 3493: 3168: 3024: 2959: 2930: 2920: 2861: 2849: 2790: 2775: 2700: 2332:

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

2277: 2034: 1853: 1727: 1476: 1436:. Many cosmic rays are kept out of the Solar System by the Sun's magnetosphere, or 1414: 1318: 1057: 958: 927: 884: 876: 791: 706: 666: 656: 543: 498: 481: 398: 333: 103: 27: 5437: 4686: 3169:"Magnetoreception | The Lohmann Lab – University of North Carolina at Chapel Hill" 1775: 1584:

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

1475:

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

1290: 8419: 8402: 8359: 8349: 8241: 7923: 7918: 7380: 7342: 7168: 6970: 6944: 6891: 6714: 6469: 6456: 6445: 6426: 6332: 5454: 5007:"Estimating global ocean heat content from tidal magnetic satellite observations" 4708: 4206:

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

4017: 3883: 3048: 2805: 2800: 2403: 2107: 1788: 1623: 1026: 922:

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

907: 726: 651: 646: 513: 388: 353: 213: 113: 5885:"Electromagnetic Interference Disrupts Bird Navigation, Hints at Quantum Action" 3632:

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

2420:(function of position) that satisfies certain properties. A magnetic field is a 766: 8533: 8452: 8442: 8306: 8301: 8060: 8050: 7949: 7877: 7657: 7385: 7362: 7352: 7332: 7215: 7163: 7097: 7059: 7054: 7006: 6886: 6642: 6433: 5963: 5030: 4480: 4455: 4231: 4116: 4051: 3935: 2762: 2706: 1681: 1500: 1227: 962: 864: 686: 681: 503: 393: 318: 268: 218: 191: 148: 123: 93: 86: 7462: 5960:

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

5788: 4254:"Paleomagnetic Evidence for the Existence of the Geomagnetic Field 3.5 Ga Ago" 2935: 2742: 1348:

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

1083:. Facing magnetic North, the angle the field makes with the horizontal is the 844: 8548: 8462: 8392: 8344: 8311: 8183: 8173: 8163: 8123: 8118: 7872: 7707: 7702: 7614: 7609: 7534: 7400: 7194: 6975: 6911: 6860: 6493:. Vol. 17 (11th ed.). Cambridge University Press. pp. 353–385. 6484: 6478: 6251: 6151: 5853: 5613: 5115:"The Intensity of the Earth's Magnetic Force Reduced to Absolute Measurement" 4992: 4715:(New millennium ed.). New York: BasicBooks. pp. 13–3, 15–14, 17–2. 4421: 4125: 3041: 2688: 2084: 1876: 1811: 1576:

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

1460: 1402:

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

1365: 1038: 966: 801: 786: 771: 711: 423: 338: 323: 238: 223: 128: 6411: 5692: 5428: 5403: 5261: 4356: 4278: 4253: 3724: 8505: 8467: 8457: 8447: 8387: 8168: 8013: 8003: 7903: 7634: 7629: 7604: 7425: 7077: 7001: 6934: 6929: 6896: 6719: 6134: 6115: 6079: 5861: 5796: 5711: 5652: 5591: 5208: 5099: 5048: 4901: 4812: 4694: 4622: 4603: 4489: 4364: 4143: 3808: 3399:

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

2876: 2710: 2421: 2417: 2350: 2290: 2114: 1753: 1643: 1551: 1512: 1445: 1433: 1422: 1410: 1395: 1391: 1380: 1341: 1187: 1148: 1144: 1095: 1018: 781: 676: 641: 583: 518: 438: 403: 283: 158: 6498: 6463:

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

6384: 6060: 5644: 2963: 2430:, each component is the derivative of the same scalar function called the 1863:

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

1599:

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

1492: 1428:

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

1134:

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

8264: 8070: 7998: 7908: 7814: 7677: 7667: 7317: 7158: 7024: 6980: 6965: 6291: 4879: 4852: 4412: 4387: 4319: 4294: 3523: 2660: 2257: 2254: 2250:

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

2232: 1857: 1692: 1535: 1437: 1399: 990: 986: 978: 701: 553: 383: 45: 6089:"Deep-Earth reactor: Nuclear fission, helium, and the geomagnetic field" 6014:"Earth's core may have hardened just in time to save its magnetic field" 5958:

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

5845: 5545: 4853:"Recent geodynamo simulations and observations of the geomagnetic field" 4804: 2554:. The magnetic field, being a derivative of the potential, drops off as 1676:, occurred about 780,000 years ago. A related phenomenon, a geomagnetic 8354: 8321: 8296: 8178: 8098: 8008: 7649: 7599: 7573: 7568: 7357: 7282: 7138: 7113: 7092: 7069: 6996: 6901: 6543: 6415:, History of the discovery of Earth's magnetic field by David P. Stern. 4635: 3816: 2770: 2409: 2378: 2282: 2156: 2095: 1762: 1429: 1370: 1198: 982: 970: 915: 872: 418: 7210: 6842: 6275: 6172: 5498: 3497: 3268: 3266: 3028: 2293:

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

1327:

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

1208:(map of inclination contours) for the Earth's magnetic field is shown 8286: 8231: 8216: 8188: 8158: 8085: 8018: 7898: 7893: 7594: 7563: 7184: 7039: 6906: 6667: 6336:. American Geophysical Union Geomagnetism and Paleomagnetism Section. 4923: 3996: 2853: 2795: 2049: 2048:

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

1864: 1708: 1696: 1403: 900: 741: 716: 528: 50: 5750: 5725: 5351: 5200: 5090: 5063: 2901:"International Geomagnetic Reference Field: the eleventh generation" 2364: 1413:, a donut-shaped region containing low-energy charged particles, or 989:

that would otherwise strip away the upper atmosphere, including the

973:

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

5455:"The International Geomagnetic Reference Field: A "Health" Warning" 4456:"Earth's magnetic field is acting up and geologists don't know why" 3263: 2543:

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

2407:

is equivalent to two opposing charges brought close together and a

2099: 974: 493: 488: 108: 7503: 5779: 1006:

Calculations of the loss of carbon dioxide from the atmosphere of

8379: 8256: 8226: 8042: 8023: 7745: 7446: 7016: 6803: 4991:

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

4977: 2401:

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

1799: 1779:

Variations in virtual axial dipole moment since the last reversal

1539: 1432:, high-energy charged particles that are mostly from outside the 1239:

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

942: 931: 463: 5666:

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

3120:

Looking into the Earth: An introduction to Geological Geophysics

8246: 8113: 8093: 7799: 7771: 7553: 6352: 5986: 4090:

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

2523:

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

2298: 2206: 2182: 1795: 1740:, part of which is shown in the image. This forms the basis of 1665: 1596:

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

1546: 1509: 1453: 1306: 548: 55: 6449: 5404:"Evaluation of candidate geomagnetic field models for IGRF-11" 3297:"Ancient lava reveals secrets of Earth's magnetic field cycle" 2297:, kilns, some types of stone structures, and even ditches and 1041:

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

8434: 8211: 8193: 8033: 7972: 7251: 4333: 3849: 3634:"Cluster shows plasmasphere interacting with Van Allen belts" 2691:

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

1723: 1178:

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

957:

respectively, abruptly switch places. These reversals of the

849: 6430:, Educational web site by David P. Stern and Mauricio Peredo 5630: 3748:"Sun Often "Tears Out A Wall" In Earth's Solar Storm Shield" 8485: 8103: 7430: 6340: 6093: 6038: 5239: 2652: 2648: 1046: 1007: 892: 6772: 5819: 5764: 5005:

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

3631: 2678:(EMM), which extends to degree and order 790 and resolves 2667:, and primary/induced magnetosphere/ionosphere variations. 1871:); a changing magnetic field generates an electric field ( 1794:

The Earth's magnetic north pole is drifting from northern

977:. It extends several tens of thousands of kilometres into 910:

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

6225:

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

4829:"First Measurement Of Magnetic Field Inside Earth's Core" 4665:

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

4636:

European Synchrotron Radiation Facility (25 April 2013).

4292: 4161:(2nd ed.). Amsterdam: Elsevier Science. p. 38. 3247:. National High Magnetic Field Laboratory. Archived from 2261: 880: 7941: 5957: 5176: 4768: 4756: 4744: 4385: 4193: 4181: 4029: 3272: 3206: 2891: 2608:(formerly the National Geophysical Data Center) and the 2004:, which is inversely proportional to the product of the 1499:: a set of traces from magnetic observatories showing a 5401: 3585: 3583: 3581: 3579: 3577: 2175:

Sea level magnetic fields observed by satellites (NASA)

6439:

Global evolution/anomaly of the Earth's magnetic field

5665: 4504:"How does the Earth's core generate a magnetic field?" 3522:. Woods Hole Oceanographic Institution. Archived from 2897: 2582:

International Association of Geomagnetism and Aeronomy

1459:

The varying conditions in the magnetosphere, known as

1421:, with high-energy ions (energies from 0.1 to 10 918:

placed at that angle through the center of Earth. The

6326:

Geomagnetism & Paleomagnetism background material

5004: 2062: 1896: 981:, protecting Earth from the charged particles of the 5569: 5263:

Geologic Applications of Modern Aeromagnetic Surveys

4251: 4205: 3776: 3574: 3458:. Dept. of Physics and Astronomy, Georgia State Univ 3068:

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

2724: 2233:

International Real-time Magnetic Observatory Network

2201:

The Earth's magnetic field strength was measured by

3006: 2584:maintains a standard global field model called the 1699:, that can carry a permanent magnetic moment. This 5136: 3907:Dumberry, Mathieu; Finlay, Christopher C. (2007). 3848:. Canadian Geological Survey. 2011. Archived from 3368: 2643:The "comprehensive modeling" (CM) approach by the 2075: 1973: 1155:has a field of about 10,000 μT (100 G). 6296:Introduction to Geomagnetically Trapped Radiation 6086: 4936: 4510:. United States Geological Survey. Archived from 3779:Philosophical Transactions of the Royal Society A 3723:. Space Weather Prediction Center. Archived from 3067: 2831: 2424:, but if it is expressed in Cartesian components 1816: 8546: 6087:Hollenbach, D. F.; Herndon, J. M. (2001-09-25). 5457:. National Geophysical Data Center. January 2010 5359:This Dynamic Earth: The Story of Plate Tectonics 5259: 4252:McElhinney, T. N. W.; Senanayake, W. E. (1980). 3864: 2827: 2825: 2632:as well as in many civilian navigation systems. 1534:Frequently, the Earth's magnetosphere is hit by 1406:, the area where the solar wind slows abruptly. 1143:The intensity of the field is often measured in 5937:Our Magnetic Earth: The Science of Geomagnetism 5672:Proceedings of the National Academy of Sciences 5236:Comprehensive Modeling of the Geomagnetic Field 4583:Proceedings of the National Academy of Sciences 4089: 3876:Encyclopedia of Geomagnetism and Paleomagnetism 3402:. UK: Cambridge University Press. p. 228. 3093:Opdyke, Neil D.; Channell, James E. T. (1996). 3063: 3061: 3059: 3057: 1787:The nature of Earth's magnetic field is one of 6434:International Geomagnetic Reference Field 2011 5718: 5550:National Centers for Environmental Information 5449: 5447: 5291: 4984:. Scientific Visualization Studio. 2016-12-30. 4660: 4658: 3974: 3906: 3092: 3051:. Scign.jpl.nasa.gov. Retrieved on 2012-01-27. 2672:National Centers for Environmental Information 2606:National Centers for Environmental Information 1840:, with a radius of 1220 km, and a liquid 1687:The past magnetic field is recorded mostly by 7957: 7519: 7267: 6788: 6514: 6034:"Substructure of the inner core of the Earth" 5143:Annual Review of Earth and Planetary Sciences 4437:"North Magnetic Pole Moving Due to Core Flux" 3602: 3600: 3598: 3545: 3543: 3541: 2822: 2271: 1340:in 1831 to 600 kilometres (370 mi) from 1025:are thus detectable as "stripes" centered on 961:leave a record in rocks that are of value to 823: 6495:(with dozens of tables and several diagrams) 5170: 4939:Physics of the Earth and Planetary Interiors 4579:"Structural Geology of the Earth's Interior" 4392:Journal of Geophysical Research: Solid Earth 4187: 3478:Eos, Transactions American Geophysical Union 3443: 3275:The US/UK World Magnetic Model for 2020–2025 3054: 2183:Currents in the ionosphere and magnetosphere 1045:can be used to search for deposits of metal 871:out into space, where it interacts with the 6528: 5444: 5383: 4972: 4970: 4968: 4850: 4846: 4844: 4655: 4286: 3770: 3745: 3220:"An Overview of the Earth's Magnetic Field" 3117: 2604:, is produced jointly by the United States 2191: 1736:of lava flows has been used to establish a 1707:, can be acquired in more than one way. In 1633: 1398:out but the other side stretching out in a 1209: 1163: 7964: 7950: 7526: 7512: 7274: 7260: 6795: 6781: 6521: 6507: 6380:. National Geographic, September 27, 2004. 5112: 3968: 3595: 3538: 2949: 2072: 1300:Dipole model of the Earth's magnetic field 830: 816: 34: 6407:. Projects in Scientific Computing, 1996. 6124: 6114: 6069: 6059: 5778: 5749: 5701: 5691: 5659: 5427: 5089: 5061: 5038: 4878: 4740: 4738: 4736: 4734: 4732: 4612: 4602: 4561: 4479: 4411: 4318: 4277: 4133: 4115: 3870: 3798: 3609:Physics of space plasmas: an introduction 3369:Serway, Raymond A.; Chris Vuille (2006). 3342: 3322:"Geomagnetism Frequently Asked Questions" 3202: 3200: 3198: 3196: 3194: 3192: 3190: 3188: 3186: 3184: 3118:Mussett, Alan E.; Khan, M. Aftab (2000). 2934: 2924: 2868: 2586:International Geomagnetic Reference Field 1233: 1158:A map of intensity contours is called an 6420:Exploration of the Earth's Magnetosphere 6144:"Magnetic monitoring of Earth and space" 6011: 5911: 5389: 5347: 5345: 4965: 4841: 4538:"Dynamos in planets, stars and galaxies" 4531: 4529: 4435:Lovett, Richard A. (December 24, 2009). 4156: 4023: 3956: 3900: 3684: 3611:. Redwood City, Calif.: Addison-Wesley. 3549: 3475: 3395: 3389: 3345:"The Earth Has More Than One North Pole" 2363: 2327: 2281: 2161: 2149: 2094:The motion of the fluid is sustained by 1823: 1774: 1637: 1579: 1571: 1491: 1487: 1369: 1322: 1289: 1285: 1129: 843: 6031: 5934: 5499:"Geomagnetic and Electric Field Models" 4851:Kono, Masaru; Roberts, Paul H. (2002). 4780: 4762: 4750: 4707: 4664: 3589: 3422: 3416: 2630:International Hydrographic Organization 2600:Another global field model, called the 579:Electromagnetism and special relativity 8547: 6231: 6205:Geological Society of America Bulletin 4769:Merrill, McElhinny & McFadden 1996 4757:Merrill, McElhinny & McFadden 1996 4745:Merrill, McElhinny & McFadden 1996 4729: 4576: 4434: 4194:Merrill, McElhinny & McFadden 1996 4182:Merrill, McElhinny & McFadden 1996 4175: 3836: 3834: 3746:Steigerwald, Bill (16 December 2008). 3636:(Press release). European Space Agency 3375:. USA: Cengage Learning. p. 493. 3362: 3207:Merrill, McElhinny & McFadden 1996 3181: 3142: 2874: 2416:Spherical harmonics can represent any 2317: 1879:). These effects can be combined in a 1747: 7945: 7507: 7255: 6776: 6502: 6476: 6377:Why Does Earth's Magnetic Field Flip? 6202: 6012:Gramling, Carolyn (1 February 2019). 5983:Paleomagnetic Principles and Practice 5980: 5342: 4535: 4526: 4453: 3962: 3878:. Springer-Verlag. pp. 159–161. 3606: 3070:Paleomagnetism: Continents and Oceans 2879:. University of California Santa Cruz 2460:The lowest-degree Gauss coefficient, 2353:passing through the poles, and along 2308: 2029:is the time derivative of the field; 1642:Geomagnetic polarity during the late 883:. The magnetic field is generated by 599:Maxwell equations in curved spacetime 8496:Geology of solar terrestrial planets 7486: 6755: 6290: 6250: 6141: 4299:Geochemistry, Geophysics, Geosystems 3687:"The great solar superstorm of 1859" 3449: 3343:Casselman, Anne (28 February 2008). 3314: 3242: 2978:"Solar wind ripping chunks off Mars" 2952:"Solar wind hammers the ozone layer" 2618:Ministry of Defence (United Kingdom) 2499: 2246:are flown in aircraft like the UK's 1561: 7533: 7234: 5882: 5294:"Basalts from the Deep Ocean Floor" 5164:10.1146/annurev.ea.16.050188.002133 4454:Witze, Alexandra (9 January 2019). 4212:Earth and Planetary Science Letters 4032:Earth and Planetary Science Letters 3916:Earth and Planetary Science Letters 3831: 3752:THEMIS: Understanding space weather 3662:. 27 September 2004. Archived from 3552:"Earth's Inconstant Magnetic Field" 3550:Phillips, Tony (29 December 2003). 2950:Shlermeler, Quirin (3 March 2005). 2614:United States Department of Defense 2124: 2083:), there would be no diffusion. By 914:axis, as if there were an enormous 13: 6004: 5914:Introduction to geomagnetic fields 5479:. National Geophysical Data Center 3324:. National Geophysical Data Center 2984:. 25 November 2008. Archived from 2626:North Atlantic Treaty Organization 2069: 1943: 1926: 1910: 1900: 1883:for the magnetic field called the 1805: 1482: 1063: 14: 8576: 7827:Sura Ionospheric Heating Facility 6318: 6181:"Temperature of the Earth's core" 5767:Journal of Comparative Physiology 5064:"Spectroscopy: NMR down to Earth" 4978:"Ocean Tides and Magnetic Fields" 2905:Geophysical Journal International 2076:{\displaystyle \sigma =\infty \;} 1660:trade places. Evidence for these 1312: 8529: 8528: 8032: 7485: 7474: 7473: 7461: 7233: 7222: 7221: 7209: 6841: 6754: 6743: 6742: 6236:. New York, NY: The Experiment. 5229: 4986: 4563:10.1046/j.1468-4004.2002.43309.x 2926:10.1111/j.1365-246X.2010.04804.x 2755: 2741: 2727: 2575: 1961: 1953: 1936: 1904: 1409:Inside the magnetosphere is the 1359: 1273: 1261: 1249: 8237:Human impact on the environment 6346:United States Geological Survey 5876: 5813: 5758: 5633:Journal of Experimental Biology 5624: 5606: 5563: 5538: 5509: 5491: 5469: 5395: 5285: 5253: 5223: 5130: 5106: 5055: 4998: 4930: 4895: 4774: 4713:The Feynman lectures on physics 4701: 4629: 4570: 4496: 4447: 4428: 4379: 4327: 4258:Journal of Geophysical Research 4245: 4199: 4150: 4083: 4058: 3739: 3713: 3678: 3648: 3625: 3512: 3469: 3429:. USA: CRC Press. p. 148. 3336: 3289: 3236: 3212: 3161: 3136: 3111: 2694: 2657:Danish Space Research Institute 2622:Federal Aviation Administration 2561:. Quadrupole terms drop off as 1738:geomagnetic polarity time scale 1717:detrital remanent magnetization 1609:paleomagnetic secular variation 1147:, but is generally reported in 1000: 8066:Climate variability and change 7281: 6480:"Magnetism, Terrestrial" 5321:10.1180/minmag.1965.034.268.32 4159:Geomagnetism in marine geology 3122:. Cambridge University Press. 3086: 3035: 3000: 2970: 2943: 1990:is the velocity of the fluid; 1965: 1949: 1817:Earth's core and the geodynamo 1622:A 1995 study of lava flows on 1215: 1181: 1: 8491:Evolution of the Solar System 7683:Interplanetary magnetic field 7625:Magnetosphere particle motion 6341:National Geomagnetism Program 6032:Herndon, J. M. (1996-01-23). 5912:Campbell, Wallace H. (2003). 5546:"The Enhanced Magnetic Model" 4687:10.1126/science.288.5473.2007 3372:Essentials of college physics 2816: 2382:is the absolute value of the 1996:is the magnetic B-field; and 1881:partial differential equation 1568:Geomagnetic secular variation 1527:, particularly the iron-rich 1473:the "Halloween" storm of 2003 1385:interplanetary magnetic field 995:harmful ultraviolet radiation 604:Relativistic electromagnetism 8242:Evolutionary history of life 4959:10.1016/0031-9201(95)03049-3 3884:10.1007/978-1-4020-4423-6_67 3426:Static Fields and Potentials 3009:Geophysical Research Letters 2196: 1713:thermoremanent magnetization 1613:paleosecular variation (PSV) 1138: 7: 8565:Magnetic field of the Earth 7421:Precession of the equinoxes 6866:Geological history of Earth 6802: 6730:Charles Thomson Rees Wilson 6628:Upper-atmospheric lightning 6412:The Great Magnet, the Earth 6362:Will Compasses Point South? 5941:University of Chicago Press 5935:Merrill, Ronald T. (2010). 5232:"Satellite Magnetic Models" 2720: 2645:Goddard Space Flight Center 1885:magnetic induction equation 10: 8581: 8030: 7688:Heliospheric current sheet 7338:Geophysical fluid dynamics 6839: 6300:Cambridge University Press 5918:Cambridge University Press 5916:(2nd ed.). New York: 5905: 5883:Hsu, Jeremy (9 May 2014). 5477:"The World Magnetic Model" 5031:10.1038/s41598-019-44397-8 4481:10.1038/d41586-019-00007-1 4232:10.1016/j.epsl.2012.06.050 4117:10.1038/s41467-020-16888-0 4052:10.1016/j.epsl.2014.05.036 4009:(also available online at 3936:10.1016/j.epsl.2006.11.026 2698: 2321: 2275: 2272:Crustal magnetic anomalies 2244:magnetic anomaly detectors 1809: 1689:strongly magnetic minerals 1649: 1565: 1363: 1316: 1297: 1219: 1185: 937:While the North and South 329:Liénard–Wiechert potential 8514: 8476: 8433: 8378: 8320: 8255: 8202: 8132: 8084: 8041: 7979: 7971: 7886: 7835: 7792: 7716: 7648: 7582: 7541: 7455: 7439: 7371: 7310: 7289: 7203: 7177: 7106: 7068: 7015: 6989: 6953: 6920: 6880:Composition and structure 6879: 6851: 6833:Index of geology articles 6810: 6738: 6702: 6681: 6655: 6620: 6589: 6582: 6536: 6142:Love, Jeffrey J. (2008). 5789:10.1007/s00359-011-0628-7 5260:William F. Hanna (1987). 5062:Stepišnik, Janez (2006). 4157:Vacquier, Victor (1972). 3607:Parks, George K. (1991). 3520:"The Magnetic North Pole" 3396:Emiliani, Cesare (1992). 2610:British Geological Survey 2303:archaeological geophysics 2222:British Geological Survey 1850:planetary differentiation 1770: 1752:Paleomagnetic studies of 1674:Brunhes–Matuyama reversal 1521:ionospheric dynamo region 1419:Van Allen radiation belts 993:that protects Earth from 594:Mathematical descriptions 304:Electromagnetic radiation 294:Electromagnetic induction 234:Magnetic vector potential 229:Magnetic scalar potential 8501:Location in the Universe 8443:Antarctic/Southern Ocean 8142:List of sovereign states 7640:Van Allen radiation belt 7620:Magnetosphere chronology 6232:Turner, Gillian (2011). 5726:"Biology: Electric cows" 5408:Earth, Planets and Space 4542:Astronomy and Geophysics 2192:Measurement and analysis 2104:compositional convection 2056:In a perfect conductor ( 1634:Magnetic field reversals 7549:Atmospheric circulation 7348:Near-surface geophysics 6530:Atmospheric electricity 6490:Encyclopædia Britannica 6477:Chree, Charles (1911). 6399:. about pole reversals) 5693:10.1073/pnas.0811194106 5618:geomagia.gfz-potsdam.de 5614:"The GEOMAGIA database" 5429:10.5047/eps.2010.11.005 5420:2010EP&S...62..787F 5292:G. D. Nicholls (1965). 4554:2002A&G....43c...9W 4357:10.1126/science.1183445 4279:10.1029/JB085iB07p03523 4224:2012E&PSL.351...54N 4044:2014E&PSL.400..302C 3928:2007E&PSL.254..146D 3691:Technology Through Time 3685:Odenwald, Sten (2010). 3143:Temple, Robert (2006). 2676:Enhanced Magnetic Model 2226:Eskdalemuir Observatory 2089:frozen-in-field theorem 2006:electrical conductivity 1765: million years ago 1175:University of Liverpool 891:of a mixture of molten 848:Computer simulation of 144:Electrostatic induction 139:Electrostatic discharge 7559:Earth's magnetic field 7396:Earth's magnetic field 6710:Georg Wilhelm Richmann 6689:Electrodynamic tethers 6574:Earth's magnetic field 6187:. 1999. Archived from 6185:NEWTON Ask a Scientist 6116:10.1073/pnas.201393998 5592:10.1098/rsta.2000.0569 5301:Mineralogical Magazine 4604:10.1073/pnas.76.9.4192 4577:Jordan, T. H. (1979). 3809:10.1098/rsta.2000.0569 3754:. NASA. Archived from 3450:Nave, Carl R. (2010). 3042:Structure of the Earth 2811:South Atlantic Anomaly 2786:Magnetic field of Mars 2369: 2361: 2287: 2266:Kursk Magnetic Anomaly 2176: 2077: 1975: 1869:Ampère's circuital law 1856:) as well as decay of 1829: 1780: 1756:lava in Australia and 1701:remanent magnetization 1647: 1617:geomagnetic excursions 1585: 1577: 1516: 1376: 1328: 1295: 1234:Geographical variation 1168:South Atlantic Anomaly 1135: 1023:reversals of the field 947:Earth's field reverses 924:South geomagnetic pole 920:North geomagnetic pole 857:Earth's magnetic field 853: 574:Electromagnetic tensor 8222:Biogeochemical cycles 8147:dependent territories 7663:Coronal mass ejection 7583:Earth's magnetosphere 7468:Geophysics portal 7391:Earth's energy budget 7129:Environmental geology 6673:Equatorial electrojet 6569:Atmospheric chemistry 6404:When North Goes South 6061:10.1073/pnas.93.2.646 5645:10.1242/jeb.202.8.891 5352:Jacqueline W. Kious; 4858:Reviews of Geophysics 4536:Weiss, Nigel (2002). 4443:on December 28, 2009. 4096:Nature Communications 3423:Manners, Joy (2000). 3095:Magnetic Stratigraphy 2964:10.1038/news050228-12 2735:Earth sciences portal 2367: 2331: 2285: 2174: 2150:Effect of ocean tides 2078: 1976: 1827: 1778: 1662:geomagnetic reversals 1641: 1583: 1575: 1556:artificial satellites 1495: 1488:Short-term variations 1469:coronal mass ejection 1375:7) Plasmasphere. 1373: 1326: 1293: 1286:Dipolar approximation 1133: 887:due to the motion of 847: 567:Covariant formulation 359:Synchrotron radiation 299:Electromagnetic pulse 289:Electromagnetic field 8270:Computer cartography 7994:Prebiotic atmosphere 7836:Other magnetospheres 7698:Solar particle event 7088:Planetary geophysics 6559:Atmospheric dynamics 5981:Tauxe, Lisa (1998). 5362:. USGS. p. 17. 4880:10.1029/2000RG000102 4835:. December 17, 2010. 4413:10.1029/2023JB027706 4320:10.1029/2009GC002496 3872:Constable, Catherine 3224:www.geomag.bgs.ac.uk 2781:Geomagnetic latitude 2620:, the United States 2602:World Magnetic Model 2344:is equal to 0 along 2264:bodies, such as the 2203:Carl Friedrich Gauss 2131:magnetohydrodynamics 2060: 2002:magnetic diffusivity 1894: 1846:core-mantle boundary 1652:Geomagnetic reversal 1452:while also emitting 1241:World Magnetic Model 1222:Magnetic declination 1164:World Magnetic Model 1127:(Down) coordinates. 1054:magnetic declination 955:South Magnetic Poles 875:, a stream of 859:, also known as the 609:Stress–energy tensor 534:Reluctance (complex) 279:Displacement current 8413:Geologic time scale 8134:Culture and society 7989:Atmosphere of Earth 7440:Related disciplines 7406:Geothermal gradient 7190:Petroleum geologist 7154:Forensic geophysics 7124:Engineering geology 6871:Timeline of geology 6823:Glossary of geology 6554:Atmospheric physics 6549:Atmospheric science 6268:1954Geop...19..281W 6217:1984GSAB...95..221T 6165:2008PhT....61b..31H 6107:2001PNAS...9811085H 6052:1996PNAS...93..646H 5846:10.1038/nature13290 5838:2014Natur.509..353E 5742:2009Natur.458Q.389. 5736:(7237): 389. 2009. 5684:2009PNAS..106.5708B 5584:2000RSPTA.358..957J 5517:"Model information" 5313:1965MinM...34..373N 5193:2002Natur.416..620H 5156:1988AREPS..16..389C 5138:Courtillot, Vincent 5113:Gauss, C.F (1832). 5082:2006Natur.439..799S 5023:2019NatSR...9.7893I 4951:1995PEPI...91...63G 4916:1995PhPl....2.1421K 4871:2002RvGeo..40.1013K 4805:10.1038/nature09643 4797:2010Natur.468..952B 4709:Feynman, Richard P. 4679:2000Sci...288.2007B 4673:(5473): 2007–2012. 4595:1979PNAS...76.4192J 4472:2019Natur.565..143W 4404:2024JGRB..12927706N 4349:2010Sci...327.1238T 4343:(5970): 1238–1240. 4311:2009GGG....10.9Z07U 4270:1980JGR....85.3523M 4108:2020NatCo..11.3371D 3989:1995Natur.374..687C 3842:"Secular variation" 3791:2000RSPTA.358..957J 3490:1996EOSTr..77..345C 3349:Scientific American 3243:Palm, Eric (2011). 3145:The Genius of China 3021:1992GeoRL..19.2151L 2917:2010GeoJI.183.1216F 2846:1995Natur.377..203G 2374:spherical harmonics 2324:Multipole expansion 2318:Spherical harmonics 2220:, for example, the 2098:, motion driven by 1748:Earliest appearance 1742:magnetostratigraphy 1554:and disruptions in 1467:, can occur when a 1194:North Magnetic Pole 1153:refrigerator magnet 1035:magnetostratigraphy 889:convection currents 879:emanating from the 524:Magnetomotive force 409:Electromotive force 379:Alternating current 314:Jefimenko equations 274:Cyclotron radiation 8408:Geological history 8282:Geodetic astronomy 7323:Geophysical survey 7216:Geology portal 7144:Geologic modelling 7083:Geophysical survey 7035:Geodetic astronomy 6961:Structural geology 6922:Historical geology 6853:History of geology 6828:History of geology 6818:Outline of geology 6597:Radio atmospherics 6564:Atmospheric dynamo 6468:2018-07-20 at the 6455:2007-10-31 at the 6444:2016-06-24 at the 6425:2013-02-14 at the 6368:The New York Times 6359:William J. Broad, 6331:2013-03-03 at the 5521:ccmc.gsfc.nasa.gov 5011:Scientific Reports 4904:Physics of Plasmas 4514:on 18 January 2015 4196:, pp. 148–155 4016:2012-03-14 at the 3727:on 22 October 2013 3701:on 12 October 2009 3562:on 1 November 2022 3097:. Academic Press. 3072:. Academic Press. 3047:2013-03-15 at the 2936:20.500.11850/27303 2875:Glatzmaier, Gary. 2680:magnetic anomalies 2637:magnetic anomalies 2433:magnetic potential 2370: 2362: 2309:Statistical models 2288: 2177: 2073: 1971: 1830: 1781: 1734:Radiometric dating 1726:wells up from the 1648: 1586: 1578: 1517: 1465:geomagnetic storms 1377: 1329: 1296: 1136: 1043:magnetic anomalies 969:extends above the 912:Earth's rotational 897:Earth's outer core 867:that extends from 854: 372:Electrical network 209:Gauss magnetic law 174:Static electricity 134:Electric potential 8542: 8541: 8478:Planetary science 8398:Extremes on Earth 8365:Signal processing 7939: 7938: 7793:Research projects 7761: 7732: 7673:Geomagnetic storm 7590:Birkeland current 7501: 7500: 7416:Mantle convection 7249: 7248: 7134:Planetary geology 7050:Planetary geodesy 6770: 6769: 6651: 6650: 6621:Optical emissions 6590:ELF/VLF emissions 6309:978-0-521-61611-9 6276:10.1190/1.1437994 6243:978-1-61519-031-7 6173:10.1063/1.2883907 5996:978-0-7923-5258-7 5973:978-0-12-491246-5 5950:978-0-226-52050-6 5927:978-0-521-52953-2 5832:(7500): 353–356. 5578:(1768): 957–990. 5369:978-0-16-048220-5 5354:Robert I. Tilling 5187:(6881): 620–623. 5076:(7078): 799–801. 4791:(7326): 952–954. 4722:978-0-465-02494-0 4466:(7738): 143–144. 4168:978-0-08-087042-7 3983:(6524): 687–692. 3893:978-1-4020-3992-8 3785:(1768): 957–990. 3618:978-0-201-50821-5 3526:on 19 August 2013 3498:10.1029/96EO00237 3436:978-0-7503-0718-5 3409:978-0-521-40949-0 3382:978-0-495-10619-7 3154:978-0-671-62028-8 3147:. Andre Deutsch. 3129:978-0-521-78085-8 3104:978-0-12-527470-8 3079:978-0-12-483355-5 3029:10.1029/92GL02485 3015:(21): 2151–2154. 2840:(6546): 203–209. 2749:Geophysics portal 2500:Radial dependence 2438:Gauss coefficient 2218:Geological survey 2172: 1917: 1658:geomagnetic poles 1590:secular variation 1562:Secular variation 1338:Boothia Peninsula 1012:of its atmosphere 959:geomagnetic poles 885:electric currents 877:charged particles 861:geomagnetic field 840: 839: 539:Reluctance (real) 509:Gyrator–capacitor 454:Resonant cavities 344:Maxwell equations 8572: 8532: 8531: 8425:History of Earth 8076:Paleoclimatology 8036: 7966: 7959: 7952: 7943: 7942: 7777:Van Allen Probes 7759: 7730: 7542:Submagnetosphere 7528: 7521: 7514: 7505: 7504: 7489: 7488: 7477: 7476: 7466: 7465: 7411:Gravity of Earth 7276: 7269: 7262: 7253: 7252: 7237: 7236: 7225: 7224: 7214: 7213: 7149:Forensic geology 7119:Economic geology 7045:Gravity of Earth 6940:Paleoclimatology 6845: 6797: 6790: 6783: 6774: 6773: 6758: 6757: 6746: 6745: 6694:Magnetotellurics 6663:Solar irradiance 6587: 6586: 6583:Electromagnetism 6523: 6516: 6509: 6500: 6499: 6494: 6482: 6371:, July 13, 2004. 6353:BGS Geomagnetism 6348:, March 8, 2011. 6313: 6287: 6247: 6228: 6199: 6197: 6196: 6176: 6148: 6138: 6128: 6118: 6101:(20): 11085–90. 6083: 6073: 6063: 6028: 6026: 6024: 6000: 5977: 5954: 5931: 5900: 5899: 5897: 5895: 5880: 5874: 5873: 5817: 5811: 5808: 5782: 5762: 5756: 5755: 5753: 5722: 5716: 5715: 5705: 5695: 5663: 5657: 5656: 5628: 5622: 5621: 5610: 5604: 5603: 5567: 5561: 5560: 5558: 5556: 5548:. United States 5542: 5536: 5535: 5533: 5532: 5523:. Archived from 5513: 5507: 5506: 5495: 5489: 5488: 5486: 5484: 5473: 5467: 5466: 5464: 5462: 5451: 5442: 5441: 5431: 5399: 5393: 5387: 5381: 5380: 5378: 5376: 5349: 5340: 5339: 5337: 5335: 5329: 5323:. Archived from 5307:(268): 373–388. 5298: 5289: 5283: 5282: 5280: 5278: 5268: 5257: 5251: 5250: 5248: 5246: 5227: 5221: 5220: 5174: 5168: 5167: 5134: 5128: 5127: 5125: 5124: 5119: 5110: 5104: 5103: 5093: 5059: 5053: 5052: 5042: 5002: 4996: 4990: 4989: 4985: 4974: 4963: 4962: 4934: 4928: 4927: 4924:10.1063/1.871485 4910:(5): 1421–1431. 4899: 4893: 4892: 4882: 4848: 4839: 4836: 4824: 4778: 4772: 4766: 4760: 4754: 4748: 4742: 4727: 4726: 4705: 4699: 4698: 4662: 4653: 4652: 4650: 4648: 4633: 4627: 4626: 4616: 4606: 4589:(9): 4192–4200. 4574: 4568: 4567: 4565: 4548:(3): 3.09–3.15. 4533: 4524: 4523: 4521: 4519: 4500: 4494: 4493: 4483: 4451: 4445: 4444: 4439:. Archived from 4432: 4426: 4425: 4415: 4383: 4377: 4376: 4331: 4325: 4324: 4322: 4290: 4284: 4283: 4281: 4249: 4243: 4242: 4240: 4238: 4203: 4197: 4191: 4185: 4179: 4173: 4172: 4154: 4148: 4147: 4137: 4119: 4087: 4081: 4080: 4078: 4076: 4062: 4056: 4055: 4027: 4021: 4008: 3997:10.1038/374687a0 3972: 3966: 3960: 3954: 3953: 3951: 3950: 3944: 3938:. Archived from 3922:(1–2): 146–157. 3913: 3904: 3898: 3897: 3868: 3862: 3861: 3859: 3857: 3838: 3829: 3828: 3802: 3774: 3768: 3767: 3765: 3763: 3758:on 16 March 2010 3743: 3737: 3736: 3734: 3732: 3717: 3711: 3710: 3708: 3706: 3697:. Archived from 3682: 3676: 3675: 3673: 3671: 3652: 3646: 3645: 3643: 3641: 3629: 3623: 3622: 3604: 3593: 3587: 3572: 3571: 3569: 3567: 3558:. Archived from 3547: 3536: 3535: 3533: 3531: 3516: 3510: 3509: 3473: 3467: 3466: 3464: 3463: 3447: 3441: 3440: 3420: 3414: 3413: 3393: 3387: 3386: 3366: 3360: 3359: 3357: 3355: 3340: 3334: 3333: 3331: 3329: 3318: 3312: 3311: 3309: 3308: 3293: 3287: 3286: 3284: 3282: 3270: 3261: 3260: 3258: 3256: 3251:on 21 March 2013 3240: 3234: 3233: 3231: 3230: 3216: 3210: 3204: 3179: 3178: 3176: 3175: 3165: 3159: 3158: 3140: 3134: 3133: 3115: 3109: 3108: 3090: 3084: 3083: 3065: 3052: 3039: 3033: 3032: 3004: 2998: 2997: 2995: 2993: 2974: 2968: 2967: 2947: 2941: 2940: 2938: 2928: 2911:(3): 1216–1230. 2895: 2889: 2888: 2886: 2884: 2872: 2866: 2865: 2854:10.1038/377203a0 2829: 2791:Magnetotellurics 2776:Geomagnetic jerk 2765: 2760: 2759: 2751: 2746: 2745: 2737: 2732: 2731: 2730: 2701:Magnetoreception 2628:(NATO), and the 2571: 2567: 2560: 2553: 2546: 2539: 2529: 2522: 2513: 2495: 2486: 2477: 2468: 2456: 2447: 2429: 2390: 2359: 2349: 2343: 2278:Magnetic anomaly 2211:Ørsted satellite 2173: 2135:kinematic dynamo 2125:Numerical models 2082: 2080: 2079: 2074: 2040: 2035:Laplace operator 2032: 2028: 2017: 2010: 1999: 1995: 1989: 1980: 1978: 1977: 1972: 1964: 1956: 1939: 1934: 1933: 1918: 1916: 1908: 1907: 1898: 1854:iron catastrophe 1766: 1664:can be found in 1525:Earth's interior 1477:Carrington Event 1346:magnetic equator 1319:Geomagnetic pole 1277: 1265: 1253: 1160:isodynamic chart 1126: 1120: 1114: 1108: 1092: 1078: 1058:magnetoreception 1027:mid-ocean ridges 928:Ellesmere Island 869:Earth's interior 832: 825: 818: 499:Electric machine 482:Magnetic circuit 444:Parallel circuit 434:Network analysis 399:Electric current 334:London equations 179:Triboelectricity 169:Potential energy 38: 28:Electromagnetism 19: 18: 8580: 8579: 8575: 8574: 8573: 8571: 8570: 8569: 8545: 8544: 8543: 8538: 8510: 8472: 8429: 8420:Geologic record 8374: 8360:Plate tectonics 8350:Mineral physics 8330:Earth structure 8316: 8251: 8198: 8128: 8080: 8037: 8028: 7975: 7970: 7940: 7935: 7882: 7831: 7788: 7712: 7644: 7578: 7537: 7535:Magnetospherics 7532: 7502: 7497: 7460: 7451: 7435: 7386:Coriolis effect 7381:Chandler wobble 7373: 7367: 7343:Mineral physics 7306: 7285: 7280: 7250: 7245: 7208: 7199: 7173: 7169:Mineral physics 7102: 7064: 7011: 6985: 6971:Plate tectonics 6949: 6945:Palaeogeography 6916: 6892:Crystallography 6875: 6847: 6846: 6837: 6806: 6801: 6771: 6766: 6734: 6715:Egon Schweidler 6698: 6677: 6647: 6638:St. Elmo's fire 6616: 6578: 6532: 6527: 6473:. July 19, 2017 6470:Wayback Machine 6457:Wayback Machine 6446:Wayback Machine 6427:Wayback Machine 6333:Wayback Machine 6321: 6316: 6310: 6244: 6194: 6192: 6179: 6146: 6022: 6020: 6007: 6005:Further reading 5997: 5974: 5951: 5928: 5908: 5903: 5893: 5891: 5881: 5877: 5818: 5814: 5763: 5759: 5751:10.1038/458389a 5724: 5723: 5719: 5678:(14): 5708–13. 5664: 5660: 5629: 5625: 5612: 5611: 5607: 5568: 5564: 5554: 5552: 5544: 5543: 5539: 5530: 5528: 5515: 5514: 5510: 5497: 5496: 5492: 5482: 5480: 5475: 5474: 5470: 5460: 5458: 5453: 5452: 5445: 5414:(10): 787–804. 5400: 5396: 5388: 5384: 5374: 5372: 5370: 5350: 5343: 5333: 5331: 5330:on 16 July 2017 5327: 5296: 5290: 5286: 5276: 5274: 5266: 5258: 5254: 5244: 5242: 5230:Frey, Herbert. 5228: 5224: 5201:10.1038/416620a 5175: 5171: 5135: 5131: 5122: 5120: 5117: 5111: 5107: 5091:10.1038/439799a 5060: 5056: 5003: 4999: 4987: 4976: 4975: 4966: 4935: 4931: 4900: 4896: 4849: 4842: 4827: 4779: 4775: 4767: 4763: 4755: 4751: 4743: 4730: 4723: 4706: 4702: 4663: 4656: 4646: 4644: 4634: 4630: 4575: 4571: 4534: 4527: 4517: 4515: 4502: 4501: 4497: 4452: 4448: 4433: 4429: 4384: 4380: 4332: 4328: 4291: 4287: 4250: 4246: 4236: 4234: 4204: 4200: 4192: 4188: 4180: 4176: 4169: 4155: 4151: 4088: 4084: 4074: 4072: 4064: 4063: 4059: 4028: 4024: 4018:Wayback Machine 3973: 3969: 3961: 3957: 3948: 3946: 3942: 3911: 3905: 3901: 3894: 3869: 3865: 3855: 3853: 3852:on 25 July 2008 3840: 3839: 3832: 3800:10.1.1.560.5046 3775: 3771: 3761: 3759: 3744: 3740: 3730: 3728: 3719: 3718: 3714: 3704: 3702: 3683: 3679: 3669: 3667: 3666:on 21 June 2013 3654: 3653: 3649: 3639: 3637: 3630: 3626: 3619: 3605: 3596: 3592:, pages 126–141 3588: 3575: 3565: 3563: 3548: 3539: 3529: 3527: 3518: 3517: 3513: 3474: 3470: 3461: 3459: 3448: 3444: 3437: 3421: 3417: 3410: 3394: 3390: 3383: 3367: 3363: 3353: 3351: 3341: 3337: 3327: 3325: 3320: 3319: 3315: 3306: 3304: 3301:Cosmos Magazine 3295: 3294: 3290: 3280: 3278: 3271: 3264: 3254: 3252: 3241: 3237: 3228: 3226: 3218: 3217: 3213: 3205: 3182: 3173: 3171: 3167: 3166: 3162: 3155: 3141: 3137: 3130: 3116: 3112: 3105: 3091: 3087: 3080: 3066: 3055: 3049:Wayback Machine 3040: 3036: 3005: 3001: 2991: 2989: 2988:on 4 March 2016 2976: 2975: 2971: 2948: 2944: 2896: 2892: 2882: 2880: 2877:"The Geodynamo" 2873: 2869: 2830: 2823: 2819: 2806:Rings of Saturn 2801:Operation Argus 2761: 2754: 2747: 2740: 2733: 2728: 2726: 2723: 2703: 2697: 2578: 2569: 2566: 2562: 2559: 2555: 2552: 2548: 2547:) drops off as 2544: 2538: 2535: 2534:with radius as 2528: 2524: 2521: 2520: 2515: 2512: 2511: 2506: 2502: 2494: 2491: 2488: 2485: 2482: 2479: 2476: 2473: 2470: 2467: 2464: 2461: 2455: 2454: 2449: 2446: 2445: 2440: 2428: 2425: 2389: 2386: 2358: 2354: 2348: 2345: 2342: 2341: 2336: 2333: 2326: 2320: 2311: 2280: 2274: 2199: 2194: 2185: 2162: 2152: 2143:self-consistent 2127: 2108:Coriolis effect 2061: 2058: 2057: 2038: 2030: 2019: 2015: 2008: 1997: 1991: 1985: 1960: 1952: 1935: 1929: 1925: 1909: 1903: 1899: 1897: 1895: 1892: 1891: 1819: 1814: 1808: 1806:Physical origin 1789:heteroscedastic 1773: 1761: 1750: 1691:, particularly 1654: 1636: 1624:Steens Mountain 1619:and reversals. 1570: 1564: 1504: 1490: 1485: 1483:Time dependence 1368: 1362: 1321: 1315: 1302: 1288: 1281: 1278: 1269: 1266: 1257: 1254: 1245: 1236: 1224: 1218: 1206:isoclinic chart 1190: 1184: 1141: 1125: 1122: 1119: 1116: 1113: 1110: 1107: 1104: 1091: 1088: 1077: 1074: 1066: 1064:Characteristics 1003: 963:paleomagnetists 908:magnetic dipole 836: 807: 806: 622: 614: 613: 569: 559: 558: 514:Induction motor 484: 474: 473: 389:Current density 374: 364: 363: 354:Poynting vector 264: 262:Electrodynamics 254: 253: 249:Right-hand rule 214:Magnetic dipole 204:Biot–Savart law 194: 184: 183: 119:Electric dipole 114:Electric charge 89: 17: 12: 11: 5: 8578: 8568: 8567: 8562: 8557: 8540: 8539: 8537: 8536: 8526: 8521: 8515: 8512: 8511: 8509: 8508: 8503: 8498: 8493: 8488: 8482: 8480: 8474: 8473: 8471: 8470: 8465: 8460: 8455: 8453:Atlantic Ocean 8450: 8445: 8439: 8437: 8431: 8430: 8428: 8427: 8422: 8417: 8416: 8415: 8405: 8400: 8395: 8390: 8384: 8382: 8376: 8375: 8373: 8372: 8367: 8362: 8357: 8352: 8347: 8342: 8337: 8335:Fluid dynamics 8332: 8326: 8324: 8318: 8317: 8315: 8314: 8309: 8307:Geopositioning 8304: 8302:Remote Sensing 8299: 8294: 8289: 8284: 8279: 8274: 8273: 8272: 8261: 8259: 8253: 8252: 8250: 8249: 8244: 8239: 8234: 8229: 8224: 8219: 8214: 8208: 8206: 8200: 8199: 8197: 8196: 8191: 8186: 8181: 8176: 8171: 8166: 8161: 8156: 8151: 8150: 8149: 8138: 8136: 8130: 8129: 8127: 8126: 8121: 8116: 8111: 8106: 8101: 8096: 8090: 8088: 8082: 8081: 8079: 8078: 8073: 8068: 8063: 8061:Climate change 8058: 8056:Energy balance 8053: 8051:Climate system 8047: 8045: 8039: 8038: 8031: 8029: 8027: 8026: 8021: 8016: 8011: 8006: 8001: 7996: 7991: 7985: 7983: 7977: 7976: 7969: 7968: 7961: 7954: 7946: 7937: 7936: 7934: 7933: 7932: 7931: 7926: 7921: 7916: 7906: 7901: 7896: 7890: 7888: 7887:Related topics 7884: 7883: 7881: 7880: 7875: 7870: 7865: 7860: 7855: 7850: 7845: 7839: 7837: 7833: 7832: 7830: 7829: 7824: 7819: 7818: 7817: 7807: 7802: 7796: 7794: 7790: 7789: 7787: 7786: 7779: 7774: 7769: 7762: 7753: 7748: 7743: 7738: 7733: 7724: 7720: 7718: 7714: 7713: 7711: 7710: 7705: 7700: 7695: 7690: 7685: 7680: 7675: 7670: 7665: 7660: 7658:Magnetic cloud 7654: 7652: 7646: 7645: 7643: 7642: 7637: 7632: 7627: 7622: 7617: 7612: 7607: 7602: 7597: 7592: 7586: 7584: 7580: 7579: 7577: 7576: 7571: 7566: 7561: 7556: 7551: 7545: 7543: 7539: 7538: 7531: 7530: 7523: 7516: 7508: 7499: 7498: 7496: 7495: 7483: 7471: 7456: 7453: 7452: 7450: 7449: 7443: 7441: 7437: 7436: 7434: 7433: 7428: 7423: 7418: 7413: 7408: 7403: 7398: 7393: 7388: 7383: 7377: 7375: 7369: 7368: 7366: 7365: 7363:Tectonophysics 7360: 7355: 7353:Paleomagnetism 7350: 7345: 7340: 7335: 7333:Geomathematics 7330: 7325: 7320: 7314: 7312: 7308: 7307: 7305: 7304: 7299: 7293: 7291: 7287: 7286: 7279: 7278: 7271: 7264: 7256: 7247: 7246: 7244: 7243: 7231: 7219: 7204: 7201: 7200: 7198: 7197: 7192: 7187: 7181: 7179: 7175: 7174: 7172: 7171: 7166: 7164:Mining geology 7161: 7156: 7151: 7146: 7141: 7136: 7131: 7126: 7121: 7116: 7110: 7108: 7104: 7103: 7101: 7100: 7098:Tectonophysics 7095: 7090: 7085: 7080: 7074: 7072: 7066: 7065: 7063: 7062: 7060:Geopositioning 7057: 7055:Remote sensing 7052: 7047: 7042: 7037: 7032: 7027: 7021: 7019: 7013: 7012: 7010: 7009: 7007:Marine geology 7004: 6999: 6993: 6991: 6987: 6986: 6984: 6983: 6978: 6973: 6968: 6963: 6957: 6955: 6951: 6950: 6948: 6947: 6942: 6937: 6932: 6926: 6924: 6918: 6917: 6915: 6914: 6909: 6904: 6899: 6894: 6889: 6887:Cosmochemistry 6883: 6881: 6877: 6876: 6874: 6873: 6868: 6863: 6857: 6855: 6849: 6848: 6840: 6838: 6836: 6835: 6830: 6825: 6820: 6814: 6812: 6808: 6807: 6800: 6799: 6792: 6785: 6777: 6768: 6767: 6765: 6764: 6752: 6739: 6736: 6735: 6733: 6732: 6727: 6725:George Simpson 6722: 6717: 6712: 6706: 6704: 6700: 6699: 6697: 6696: 6691: 6685: 6683: 6679: 6678: 6676: 6675: 6670: 6665: 6659: 6657: 6653: 6652: 6649: 6648: 6646: 6645: 6643:Ball lightning 6640: 6635: 6630: 6624: 6622: 6618: 6617: 6615: 6614: 6609: 6604: 6599: 6593: 6591: 6584: 6580: 6579: 6577: 6576: 6571: 6566: 6561: 6556: 6551: 6546: 6540: 6538: 6534: 6533: 6526: 6525: 6518: 6511: 6503: 6497: 6496: 6485:Chisholm, Hugh 6474: 6459: 6436: 6431: 6416: 6408: 6400: 6385:Magnetic Storm 6381: 6372: 6357: 6349: 6337: 6320: 6319:External links 6317: 6315: 6314: 6308: 6288: 6262:(2): 281–289. 6252:Wait, James R. 6248: 6242: 6229: 6211:(2): 221–225. 6200: 6177: 6139: 6084: 6046:(2): 646–648. 6029: 6008: 6006: 6003: 6002: 6001: 5995: 5978: 5972: 5964:Academic Press 5955: 5949: 5932: 5926: 5907: 5904: 5902: 5901: 5875: 5812: 5773:(6): 677–682. 5757: 5717: 5658: 5639:(8): 891–908. 5623: 5605: 5562: 5537: 5508: 5490: 5468: 5443: 5394: 5382: 5368: 5341: 5284: 5252: 5222: 5169: 5129: 5105: 5054: 4997: 4964: 4945:(1–3): 63–75. 4929: 4894: 4840: 4838: 4837: 4773: 4761: 4749: 4728: 4721: 4700: 4654: 4628: 4569: 4525: 4495: 4446: 4427: 4378: 4326: 4285: 4244: 4198: 4186: 4174: 4167: 4149: 4082: 4057: 4022: 3967: 3955: 3899: 3892: 3863: 3830: 3769: 3738: 3712: 3677: 3647: 3624: 3617: 3594: 3573: 3537: 3511: 3468: 3442: 3435: 3415: 3408: 3388: 3381: 3361: 3335: 3313: 3288: 3262: 3235: 3211: 3180: 3160: 3153: 3135: 3128: 3110: 3103: 3085: 3078: 3053: 3034: 2999: 2969: 2942: 2890: 2867: 2820: 2818: 2815: 2814: 2813: 2808: 2803: 2798: 2793: 2788: 2783: 2778: 2773: 2767: 2766: 2763:Physics portal 2752: 2738: 2722: 2719: 2699:Main article: 2696: 2693: 2685: 2684: 2674:developed the 2668: 2577: 2574: 2564: 2557: 2550: 2536: 2526: 2518: 2516: 2509: 2507: 2501: 2498: 2492: 2489: 2483: 2480: 2474: 2471: 2465: 2462: 2452: 2450: 2443: 2441: 2426: 2387: 2356: 2346: 2339: 2337: 2334: 2319: 2316: 2310: 2307: 2276:Main article: 2273: 2270: 2253:Commercially, 2198: 2195: 2193: 2190: 2184: 2181: 2151: 2148: 2126: 2123: 2071: 2068: 2065: 1982: 1981: 1970: 1967: 1963: 1959: 1955: 1951: 1948: 1945: 1942: 1938: 1932: 1928: 1924: 1921: 1915: 1912: 1906: 1902: 1818: 1815: 1810:Main article: 1807: 1804: 1772: 1769: 1749: 1746: 1682:Laschamp event 1650:Main article: 1635: 1632: 1601:westward drift 1566:Main article: 1563: 1560: 1501:magnetic storm 1489: 1486: 1484: 1481: 1361: 1358: 1317:Main article: 1314: 1313:Magnetic poles 1311: 1287: 1284: 1283: 1282: 1279: 1272: 1270: 1267: 1260: 1258: 1255: 1248: 1237: 1235: 1232: 1228:celestial pole 1220:Main article: 1217: 1214: 1186:Main article: 1183: 1180: 1140: 1137: 1123: 1117: 1111: 1105: 1089: 1075: 1065: 1062: 1002: 999: 939:magnetic poles 895:and nickel in 865:magnetic field 838: 837: 835: 834: 827: 820: 812: 809: 808: 805: 804: 799: 794: 789: 784: 779: 774: 769: 764: 759: 754: 749: 744: 739: 734: 729: 724: 719: 714: 709: 704: 699: 694: 689: 684: 679: 674: 669: 664: 659: 654: 649: 644: 639: 634: 629: 623: 620: 619: 616: 615: 612: 611: 606: 601: 596: 591: 589:Four-potential 586: 581: 576: 570: 565: 564: 561: 560: 557: 556: 551: 546: 541: 536: 531: 526: 521: 516: 511: 506: 504:Electric motor 501: 496: 491: 485: 480: 479: 476: 475: 472: 471: 466: 461: 459:Series circuit 456: 451: 446: 441: 436: 431: 429:Kirchhoff laws 426: 421: 416: 411: 406: 401: 396: 394:Direct current 391: 386: 381: 375: 370: 369: 366: 365: 362: 361: 356: 351: 349:Maxwell tensor 346: 341: 336: 331: 326: 321: 319:Larmor formula 316: 311: 306: 301: 296: 291: 286: 281: 276: 271: 269:Bremsstrahlung 265: 260: 259: 256: 255: 252: 251: 246: 241: 236: 231: 226: 221: 219:Magnetic field 216: 211: 206: 201: 195: 192:Magnetostatics 190: 189: 186: 185: 182: 181: 176: 171: 166: 161: 156: 151: 146: 141: 136: 131: 126: 124:Electric field 121: 116: 111: 106: 101: 96: 94:Charge density 90: 87:Electrostatics 85: 84: 81: 80: 79: 78: 73: 68: 63: 58: 53: 48: 40: 39: 31: 30: 24: 23: 22:Articles about 15: 9: 6: 4: 3: 2: 8577: 8566: 8563: 8561: 8558: 8556: 8553: 8552: 8550: 8535: 8527: 8525: 8522: 8520: 8517: 8516: 8513: 8507: 8504: 8502: 8499: 8497: 8494: 8492: 8489: 8487: 8484: 8483: 8481: 8479: 8475: 8469: 8466: 8464: 8463:Pacific Ocean 8461: 8459: 8456: 8454: 8451: 8449: 8446: 8444: 8441: 8440: 8438: 8436: 8432: 8426: 8423: 8421: 8418: 8414: 8411: 8410: 8409: 8406: 8404: 8401: 8399: 8396: 8394: 8393:Earth science 8391: 8389: 8386: 8385: 8383: 8381: 8377: 8371: 8368: 8366: 8363: 8361: 8358: 8356: 8353: 8351: 8348: 8346: 8345:Magnetosphere 8343: 8341: 8338: 8336: 8333: 8331: 8328: 8327: 8325: 8323: 8319: 8313: 8312:Virtual globe 8310: 8308: 8305: 8303: 8300: 8298: 8295: 8293: 8290: 8288: 8285: 8283: 8280: 8278: 8277:Earth's orbit 8275: 8271: 8268: 8267: 8266: 8263: 8262: 8260: 8258: 8254: 8248: 8245: 8243: 8240: 8238: 8235: 8233: 8230: 8228: 8225: 8223: 8220: 8218: 8215: 8213: 8210: 8209: 8207: 8205: 8201: 8195: 8192: 8190: 8187: 8185: 8184:World history 8182: 8180: 8177: 8175: 8174:World economy 8172: 8170: 8167: 8165: 8162: 8160: 8157: 8155: 8152: 8148: 8145: 8144: 8143: 8140: 8139: 8137: 8135: 8131: 8125: 8124:South America 8122: 8120: 8119:North America 8117: 8115: 8112: 8110: 8107: 8105: 8102: 8100: 8097: 8095: 8092: 8091: 8089: 8087: 8083: 8077: 8074: 8072: 8069: 8067: 8064: 8062: 8059: 8057: 8054: 8052: 8049: 8048: 8046: 8044: 8040: 8035: 8025: 8022: 8020: 8017: 8015: 8012: 8010: 8007: 8005: 8002: 8000: 7997: 7995: 7992: 7990: 7987: 7986: 7984: 7982: 7978: 7974: 7967: 7962: 7960: 7955: 7953: 7948: 7947: 7944: 7930: 7927: 7925: 7922: 7920: 7917: 7915: 7912: 7911: 7910: 7907: 7905: 7902: 7900: 7897: 7895: 7892: 7891: 7889: 7885: 7879: 7876: 7874: 7871: 7869: 7866: 7864: 7861: 7859: 7856: 7854: 7851: 7849: 7846: 7844: 7841: 7840: 7838: 7834: 7828: 7825: 7823: 7820: 7816: 7813: 7812: 7811: 7808: 7806: 7803: 7801: 7798: 7797: 7795: 7791: 7785: 7784: 7780: 7778: 7775: 7773: 7770: 7768: 7767: 7763: 7757: 7754: 7752: 7749: 7747: 7744: 7742: 7739: 7737: 7734: 7728: 7725: 7722: 7721: 7719: 7715: 7709: 7708:Space weather 7706: 7704: 7703:Space climate 7701: 7699: 7696: 7694: 7691: 7689: 7686: 7684: 7681: 7679: 7676: 7674: 7671: 7669: 7666: 7664: 7661: 7659: 7656: 7655: 7653: 7651: 7647: 7641: 7638: 7636: 7633: 7631: 7628: 7626: 7623: 7621: 7618: 7616: 7615:Magnetosphere 7613: 7611: 7610:Magnetosheath 7608: 7606: 7603: 7601: 7598: 7596: 7593: 7591: 7588: 7587: 7585: 7581: 7575: 7572: 7570: 7567: 7565: 7562: 7560: 7557: 7555: 7552: 7550: 7547: 7546: 7544: 7540: 7536: 7529: 7524: 7522: 7517: 7515: 7510: 7509: 7506: 7494: 7493: 7484: 7482: 7481: 7472: 7470: 7469: 7464: 7458: 7457: 7454: 7448: 7445: 7444: 7442: 7438: 7432: 7429: 7427: 7424: 7422: 7419: 7417: 7414: 7412: 7409: 7407: 7404: 7402: 7399: 7397: 7394: 7392: 7389: 7387: 7384: 7382: 7379: 7378: 7376: 7370: 7364: 7361: 7359: 7356: 7354: 7351: 7349: 7346: 7344: 7341: 7339: 7336: 7334: 7331: 7329: 7326: 7324: 7321: 7319: 7316: 7315: 7313: 7309: 7303: 7302:Geophysicists 7300: 7298: 7295: 7294: 7292: 7288: 7284: 7277: 7272: 7270: 7265: 7263: 7258: 7257: 7254: 7242: 7241: 7232: 7230: 7229: 7220: 7218: 7217: 7212: 7206: 7205: 7202: 7196: 7195:Volcanologist 7193: 7191: 7188: 7186: 7183: 7182: 7180: 7176: 7170: 7167: 7165: 7162: 7160: 7157: 7155: 7152: 7150: 7147: 7145: 7142: 7140: 7137: 7135: 7132: 7130: 7127: 7125: 7122: 7120: 7117: 7115: 7112: 7111: 7109: 7105: 7099: 7096: 7094: 7091: 7089: 7086: 7084: 7081: 7079: 7076: 7075: 7073: 7071: 7067: 7061: 7058: 7056: 7053: 7051: 7048: 7046: 7043: 7041: 7038: 7036: 7033: 7031: 7030:Earth's orbit 7028: 7026: 7023: 7022: 7020: 7018: 7014: 7008: 7005: 7003: 7000: 6998: 6995: 6994: 6992: 6988: 6982: 6979: 6977: 6976:Geomorphology 6974: 6972: 6969: 6967: 6964: 6962: 6959: 6958: 6956: 6954:Dynamic Earth 6952: 6946: 6943: 6941: 6938: 6936: 6933: 6931: 6928: 6927: 6925: 6923: 6919: 6913: 6912:Sedimentology 6910: 6908: 6905: 6903: 6900: 6898: 6895: 6893: 6890: 6888: 6885: 6884: 6882: 6878: 6872: 6869: 6867: 6864: 6862: 6861:Geochronology 6859: 6858: 6856: 6854: 6850: 6844: 6834: 6831: 6829: 6826: 6824: 6821: 6819: 6816: 6815: 6813: 6809: 6805: 6798: 6793: 6791: 6786: 6784: 6779: 6778: 6775: 6763: 6762: 6753: 6751: 6750: 6741: 6740: 6737: 6731: 6728: 6726: 6723: 6721: 6718: 6716: 6713: 6711: 6708: 6707: 6705: 6701: 6695: 6692: 6690: 6687: 6686: 6684: 6680: 6674: 6671: 6669: 6666: 6664: 6661: 6660: 6658: 6654: 6644: 6641: 6639: 6636: 6634: 6631: 6629: 6626: 6625: 6623: 6619: 6613: 6610: 6608: 6605: 6603: 6600: 6598: 6595: 6594: 6592: 6588: 6585: 6581: 6575: 6572: 6570: 6567: 6565: 6562: 6560: 6557: 6555: 6552: 6550: 6547: 6545: 6542: 6541: 6539: 6535: 6531: 6524: 6519: 6517: 6512: 6510: 6505: 6504: 6501: 6492: 6491: 6486: 6481: 6475: 6472: 6471: 6467: 6464: 6460: 6458: 6454: 6451: 6447: 6443: 6440: 6437: 6435: 6432: 6429: 6428: 6424: 6421: 6417: 6414: 6413: 6409: 6406: 6405: 6401: 6398: 6394: 6391: 6387: 6386: 6382: 6379: 6378: 6373: 6370: 6369: 6364: 6363: 6358: 6355: 6354: 6350: 6347: 6343: 6342: 6338: 6335: 6334: 6330: 6327: 6323: 6322: 6311: 6305: 6301: 6297: 6293: 6289: 6285: 6281: 6277: 6273: 6269: 6265: 6261: 6257: 6253: 6249: 6245: 6239: 6235: 6230: 6226: 6222: 6218: 6214: 6210: 6206: 6201: 6191:on 2010-09-08 6190: 6186: 6182: 6178: 6174: 6170: 6166: 6162: 6158: 6154: 6153: 6152:Physics Today 6145: 6140: 6136: 6132: 6127: 6122: 6117: 6112: 6108: 6104: 6100: 6096: 6095: 6090: 6085: 6081: 6077: 6072: 6067: 6062: 6057: 6053: 6049: 6045: 6041: 6040: 6035: 6030: 6019: 6015: 6010: 6009: 5998: 5992: 5988: 5984: 5979: 5975: 5969: 5965: 5961: 5956: 5952: 5946: 5942: 5938: 5933: 5929: 5923: 5919: 5915: 5910: 5909: 5890: 5889:IEEE Spectrum 5886: 5879: 5871: 5867: 5863: 5859: 5855: 5851: 5847: 5843: 5839: 5835: 5831: 5827: 5823: 5816: 5810: 5806: 5802: 5798: 5794: 5790: 5786: 5781: 5776: 5772: 5768: 5761: 5752: 5747: 5743: 5739: 5735: 5731: 5727: 5721: 5713: 5709: 5704: 5699: 5694: 5689: 5685: 5681: 5677: 5673: 5669: 5662: 5654: 5650: 5646: 5642: 5638: 5634: 5627: 5619: 5615: 5609: 5601: 5597: 5593: 5589: 5585: 5581: 5577: 5573: 5566: 5551: 5547: 5541: 5527:on 2021-12-09 5526: 5522: 5518: 5512: 5504: 5500: 5494: 5478: 5472: 5456: 5450: 5448: 5439: 5435: 5430: 5425: 5421: 5417: 5413: 5409: 5405: 5398: 5391: 5390:Campbell 2003 5386: 5371: 5365: 5361: 5360: 5355: 5348: 5346: 5326: 5322: 5318: 5314: 5310: 5306: 5302: 5295: 5288: 5272: 5265: 5264: 5256: 5241: 5237: 5233: 5226: 5218: 5214: 5210: 5206: 5202: 5198: 5194: 5190: 5186: 5182: 5181: 5173: 5165: 5161: 5157: 5153: 5149: 5145: 5144: 5139: 5133: 5116: 5109: 5101: 5097: 5092: 5087: 5083: 5079: 5075: 5071: 5070: 5065: 5058: 5050: 5046: 5041: 5036: 5032: 5028: 5024: 5020: 5016: 5012: 5008: 5001: 4994: 4993:public domain 4983: 4979: 4973: 4971: 4969: 4960: 4956: 4952: 4948: 4944: 4940: 4933: 4925: 4921: 4917: 4913: 4909: 4905: 4898: 4890: 4886: 4881: 4876: 4872: 4868: 4864: 4860: 4859: 4854: 4847: 4845: 4834: 4830: 4826: 4825: 4822: 4818: 4814: 4810: 4806: 4802: 4798: 4794: 4790: 4786: 4785: 4777: 4770: 4765: 4758: 4753: 4746: 4741: 4739: 4737: 4735: 4733: 4724: 4718: 4714: 4710: 4704: 4696: 4692: 4688: 4684: 4680: 4676: 4672: 4668: 4661: 4659: 4643: 4639: 4632: 4624: 4620: 4615: 4610: 4605: 4600: 4596: 4592: 4588: 4584: 4580: 4573: 4564: 4559: 4555: 4551: 4547: 4543: 4539: 4532: 4530: 4513: 4509: 4505: 4499: 4491: 4487: 4482: 4477: 4473: 4469: 4465: 4461: 4457: 4450: 4442: 4438: 4431: 4423: 4419: 4414: 4409: 4405: 4401: 4397: 4393: 4389: 4382: 4374: 4370: 4366: 4362: 4358: 4354: 4350: 4346: 4342: 4338: 4330: 4321: 4316: 4312: 4308: 4304: 4300: 4296: 4289: 4280: 4275: 4271: 4267: 4263: 4259: 4255: 4248: 4233: 4229: 4225: 4221: 4217: 4213: 4209: 4202: 4195: 4190: 4183: 4178: 4170: 4164: 4160: 4153: 4145: 4141: 4136: 4131: 4127: 4123: 4118: 4113: 4109: 4105: 4101: 4097: 4093: 4086: 4071: 4067: 4061: 4053: 4049: 4045: 4041: 4037: 4033: 4026: 4019: 4015: 4012: 4006: 4002: 3998: 3994: 3990: 3986: 3982: 3978: 3971: 3964: 3959: 3945:on 2013-10-23 3941: 3937: 3933: 3929: 3925: 3921: 3917: 3910: 3903: 3895: 3889: 3885: 3881: 3877: 3873: 3867: 3851: 3847: 3843: 3837: 3835: 3826: 3822: 3818: 3814: 3810: 3806: 3801: 3796: 3792: 3788: 3784: 3780: 3773: 3757: 3753: 3749: 3742: 3726: 3722: 3721:"The K-index" 3716: 3700: 3696: 3692: 3688: 3681: 3665: 3661: 3657: 3651: 3635: 3628: 3620: 3614: 3610: 3603: 3601: 3599: 3591: 3586: 3584: 3582: 3580: 3578: 3561: 3557: 3553: 3546: 3544: 3542: 3525: 3521: 3515: 3507: 3503: 3499: 3495: 3491: 3487: 3483: 3479: 3472: 3457: 3453: 3446: 3438: 3432: 3428: 3427: 3419: 3411: 3405: 3401: 3400: 3392: 3384: 3378: 3374: 3373: 3365: 3350: 3346: 3339: 3323: 3317: 3302: 3298: 3292: 3276: 3269: 3267: 3250: 3246: 3239: 3225: 3221: 3215: 3208: 3203: 3201: 3199: 3197: 3195: 3193: 3191: 3189: 3187: 3185: 3170: 3164: 3156: 3150: 3146: 3139: 3131: 3125: 3121: 3114: 3106: 3100: 3096: 3089: 3081: 3075: 3071: 3064: 3062: 3060: 3058: 3050: 3046: 3043: 3038: 3030: 3026: 3022: 3018: 3014: 3010: 3003: 2987: 2983: 2982:Cosmos Online 2979: 2973: 2965: 2961: 2957: 2953: 2946: 2937: 2932: 2927: 2922: 2918: 2914: 2910: 2906: 2902: 2894: 2878: 2871: 2863: 2859: 2855: 2851: 2847: 2843: 2839: 2835: 2828: 2826: 2821: 2812: 2809: 2807: 2804: 2802: 2799: 2797: 2794: 2792: 2789: 2787: 2784: 2782: 2779: 2777: 2774: 2772: 2769: 2768: 2764: 2758: 2753: 2750: 2744: 2739: 2736: 2725: 2718: 2714: 2712: 2708: 2702: 2692: 2690: 2689:Paleomagnetic 2681: 2677: 2673: 2669: 2666: 2662: 2658: 2654: 2650: 2646: 2642: 2641: 2640: 2638: 2633: 2631: 2627: 2623: 2619: 2615: 2611: 2607: 2603: 2598: 2595: 2591: 2587: 2583: 2576:Global models 2573: 2541: 2533: 2530:and one that 2497: 2458: 2439: 2435: 2434: 2423: 2419: 2414: 2412: 2411: 2406: 2405: 2400: 2399: 2394: 2385: 2381: 2380: 2375: 2366: 2352: 2351:great circles 2330: 2325: 2315: 2306: 2304: 2300: 2296: 2292: 2291:Magnetometers 2284: 2279: 2269: 2267: 2263: 2259: 2256: 2251: 2249: 2245: 2241: 2236: 2234: 2229: 2227: 2223: 2219: 2214: 2212: 2208: 2204: 2189: 2180: 2160: 2158: 2147: 2144: 2139: 2136: 2132: 2122: 2119: 2116: 2115:T-Tauri phase 2111: 2109: 2105: 2101: 2097: 2092: 2090: 2086: 2066: 2063: 2054: 2051: 2046: 2044: 2043:curl operator 2036: 2027: 2023: 2014: 2007: 2003: 1994: 1988: 1968: 1957: 1946: 1940: 1930: 1922: 1919: 1913: 1890: 1889: 1888: 1886: 1882: 1878: 1877:Lorentz force 1874: 1873:Faraday's law 1870: 1866: 1861: 1859: 1855: 1851: 1847: 1843: 1839: 1835: 1826: 1822: 1813: 1812:Dynamo theory 1803: 1801: 1797: 1792: 1790: 1785: 1777: 1768: 1764: 1759: 1755: 1745: 1743: 1739: 1735: 1731: 1729: 1725: 1720: 1718: 1714: 1710: 1706: 1702: 1698: 1694: 1690: 1685: 1683: 1679: 1675: 1671: 1667: 1663: 1659: 1653: 1645: 1640: 1631: 1627: 1625: 1620: 1618: 1614: 1610: 1605: 1602: 1597: 1593: 1591: 1582: 1574: 1569: 1559: 1557: 1553: 1548: 1543: 1541: 1537: 1532: 1530: 1526: 1522: 1514: 1511: 1507: 1502: 1498: 1494: 1480: 1478: 1474: 1470: 1466: 1462: 1461:space weather 1457: 1455: 1451: 1447: 1441: 1439: 1435: 1431: 1426: 1424: 1420: 1416: 1412: 1407: 1405: 1401: 1397: 1393: 1388: 1386: 1382: 1372: 1367: 1366:Magnetosphere 1360:Magnetosphere 1357: 1355: 1349: 1347: 1344:in 2001. The 1343: 1339: 1333: 1325: 1320: 1310: 1308: 1301: 1292: 1276: 1271: 1264: 1259: 1252: 1247: 1246: 1244: 1242: 1231: 1229: 1223: 1213: 1211: 1207: 1202: 1200: 1195: 1189: 1179: 1176: 1171: 1169: 1165: 1161: 1156: 1154: 1150: 1146: 1132: 1128: 1102: 1098: 1097: 1086: 1082: 1072: 1061: 1059: 1055: 1050: 1048: 1044: 1040: 1036: 1032: 1028: 1024: 1020: 1019:igneous rocks 1015: 1013: 1009: 998: 996: 992: 988: 984: 980: 976: 972: 968: 967:magnetosphere 964: 960: 956: 952: 948: 944: 940: 935: 933: 929: 925: 921: 917: 913: 909: 904: 902: 898: 894: 890: 886: 882: 878: 874: 870: 866: 862: 858: 851: 846: 842: 833: 828: 826: 821: 819: 814: 813: 811: 810: 803: 800: 798: 795: 793: 790: 788: 785: 783: 780: 778: 775: 773: 770: 768: 765: 763: 760: 758: 755: 753: 750: 748: 745: 743: 740: 738: 735: 733: 730: 728: 725: 723: 720: 718: 715: 713: 710: 708: 705: 703: 700: 698: 695: 693: 690: 688: 685: 683: 680: 678: 675: 673: 670: 668: 665: 663: 660: 658: 655: 653: 650: 648: 645: 643: 640: 638: 635: 633: 630: 628: 625: 624: 618: 617: 610: 607: 605: 602: 600: 597: 595: 592: 590: 587: 585: 582: 580: 577: 575: 572: 571: 568: 563: 562: 555: 552: 550: 547: 545: 542: 540: 537: 535: 532: 530: 527: 525: 522: 520: 517: 515: 512: 510: 507: 505: 502: 500: 497: 495: 492: 490: 487: 486: 483: 478: 477: 470: 467: 465: 462: 460: 457: 455: 452: 450: 447: 445: 442: 440: 437: 435: 432: 430: 427: 425: 424:Joule heating 422: 420: 417: 415: 412: 410: 407: 405: 402: 400: 397: 395: 392: 390: 387: 385: 382: 380: 377: 376: 373: 368: 367: 360: 357: 355: 352: 350: 347: 345: 342: 340: 339:Lorentz force 337: 335: 332: 330: 327: 325: 322: 320: 317: 315: 312: 310: 307: 305: 302: 300: 297: 295: 292: 290: 287: 285: 282: 280: 277: 275: 272: 270: 267: 266: 263: 258: 257: 250: 247: 245: 242: 240: 239:Magnetization 237: 235: 232: 230: 227: 225: 224:Magnetic flux 222: 220: 217: 215: 212: 210: 207: 205: 202: 200: 197: 196: 193: 188: 187: 180: 177: 175: 172: 170: 167: 165: 162: 160: 157: 155: 152: 150: 147: 145: 142: 140: 137: 135: 132: 130: 129:Electric flux 127: 125: 122: 120: 117: 115: 112: 110: 107: 105: 102: 100: 97: 95: 92: 91: 88: 83: 82: 77: 74: 72: 69: 67: 66:Computational 64: 62: 59: 57: 54: 52: 49: 47: 44: 43: 42: 41: 37: 33: 32: 29: 26: 25: 21: 20: 8555:Geomagnetism 8506:Solar System 8468:Oceanography 8458:Indian Ocean 8448:Arctic Ocean 8388:Age of Earth 8340:Geomagnetism 8339: 8014:Thermosphere 8004:Stratosphere 7909:Ring systems 7904:Lunar swirls 7781: 7764: 7635:Ring current 7630:Plasmasphere 7605:Magnetopause 7558: 7490: 7478: 7459: 7426:Seismic wave 7395: 7328:Geomagnetism 7327: 7238: 7226: 7207: 7107:Applications 7078:Geomagnetism 7002:Hydrogeology 6935:Paleontology 6930:Stratigraphy 6897:Geochemistry 6759: 6747: 6720:Nikola Tesla 6682:Applications 6573: 6488: 6461: 6418: 6410: 6402: 6396: 6383: 6375: 6374:John Roach, 6366: 6360: 6351: 6339: 6324: 6295: 6292:Walt, Martin 6259: 6255: 6233: 6208: 6204: 6193:. Retrieved 6189:the original 6184: 6159:(2): 31–37. 6156: 6150: 6098: 6092: 6043: 6037: 6021:. Retrieved 6018:Science News 6017: 5982: 5959: 5936: 5913: 5892:. Retrieved 5888: 5878: 5829: 5825: 5815: 5770: 5766: 5760: 5733: 5729: 5720: 5675: 5671: 5661: 5636: 5632: 5626: 5617: 5608: 5575: 5571: 5565: 5553:. Retrieved 5540: 5529:. Retrieved 5525:the original 5520: 5511: 5502: 5493: 5481:. Retrieved 5471: 5459:. Retrieved 5411: 5407: 5397: 5392:, p. 1. 5385: 5373:. Retrieved 5358: 5332:. Retrieved 5325:the original 5304: 5300: 5287: 5275:. Retrieved 5273:. p. 66 5262: 5255: 5243:. Retrieved 5235: 5225: 5184: 5178: 5172: 5147: 5141: 5132: 5121:. Retrieved 5108: 5073: 5067: 5057: 5014: 5010: 5000: 4981: 4942: 4938: 4932: 4907: 4903: 4897: 4862: 4856: 4832: 4788: 4782: 4776: 4771:, Chapter 11 4764: 4759:, Chapter 10 4752: 4712: 4703: 4670: 4666: 4645:. Retrieved 4642:ScienceDaily 4641: 4631: 4586: 4582: 4572: 4545: 4541: 4516:. 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Retrieved 3303:. 2021-08-31 3300: 3291: 3279:. Retrieved 3253:. Retrieved 3249:the original 3238: 3227:. Retrieved 3223: 3214: 3172:. Retrieved 3163: 3144: 3138: 3119: 3113: 3094: 3088: 3069: 3037: 3012: 3008: 3002: 2990:. Retrieved 2986:the original 2981: 2972: 2955: 2945: 2908: 2904: 2893: 2881:. Retrieved 2870: 2837: 2833: 2715: 2711:Google Earth 2704: 2695:Biomagnetism 2686: 2634: 2599: 2579: 2542: 2531: 2503: 2459: 2437: 2431: 2422:vector field 2418:scalar field 2415: 2408: 2402: 2396: 2392: 2383: 2377: 2371: 2312: 2289: 2252: 2239: 2237: 2230: 2215: 2200: 2186: 2178: 2153: 2142: 2140: 2134: 2128: 2120: 2112: 2103: 2093: 2088: 2055: 2047: 2025: 2021: 2018:. 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