Last edited by Zologor
Saturday, November 14, 2020 | History

2 edition of Relation of the westward drift of the geomagnetic field to the rotation of the earth"s core found in the catalog.

Relation of the westward drift of the geomagnetic field to the rotation of the earth"s core

A. D. Richmond

Relation of the westward drift of the geomagnetic field to the rotation of the earth"s core

  • 17 Want to read
  • 31 Currently reading

Published by Rand Corp. in Santa Monica, Calif .
Written in English

    Places:
  • Earth
    • Subjects:
    • Geomagnetism.,
    • Earth -- Rotation.

    • Edition Notes

      Prepared for the National Aeronautics and Space Administration under contract no. NASr-21.

      Statement[by] A. D. Richmond.
      SeriesRand Corporation. Memorandum;, RM-5861-NASA, Memorandum (Rand Corporation) ;, RM-5861-NASA.
      ContributionsUnited States. National Aeronautics and Space Administration.
      Classifications
      LC ClassificationsQ180.A1 R36 no. 5861
      The Physical Object
      Paginationix, 18 p.
      Number of Pages18
      ID Numbers
      Open LibraryOL5690132M
      LC Control Number70012814

      Magnetic field lines are blue where the field is directed inward and orange where it is directed outward. The rotation axis of the model Earth is vertical and through the center. A transition occurs at the core-mantle boundary from the intense, complicated field structure in the fluid core, where the field is generated, to the smooth, potential. Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior to where it meets the solar wind, a stream of charged particles emanating from the magnitude at the Earth's surface ranges from 25 to 65 microteslas ( to gauss). Roughly speaking it is the field of a magnetic dipole currently tilted at an angle of about   The outer core is the source of the geomagnetic field. Graphic Credit: Dixon Rohr Unlike a hard-wired magnet, Earth’s polarity isn’t constant – it moves around a bit.


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Relation of the westward drift of the geomagnetic field to the rotation of the earth"s core by A. D. Richmond Download PDF EPUB FB2

The concept of equating the drift of the geomagnetic field with a similar drifting motion of the earth's core is examined. The drift of the field at the earth's surface and at the core is calculated, and the two values are shown to be considerably d. Calculation of the westward drift of the earth's magnetic field for epoch by the method of least-square fit.

The drifts of he magnetic potential and of the radial magnetic field are calculated at the surface of the earth and at the surface of the earth's fluid core; the values are shown to depend on the distance from the center of the earth.

Although Edmund Halley – who also discovered the famous comet – showed the westward-drifting motion of the Earth’s geomagnetic field init is the first time that scientists have been able to link the way the inner core spins to the behavior of the outer core.

The rotation of magnetic iron in Earth's core gives rise to the planet's geomagnetic field. The geomagnetic field, in turn, protects the planet from solar radiation, making it important for life on Earth. Without it, the planet's surface would be bombarded by charged particles streaming from the sun that would ultimately rip away Earth's.

The rotation of magnetic iron in Earth's core gives rise to the planet's geomagnetic field. The geomagnetic field, in turn, protects the planet from. The westerly drift of the Earth's magnetic field was first described by Edmund Halley in Halley noted that many of the changes in the field that had been observed in the previous century, such as the shift in the position of no variation from Cape d'Agulhas to the meridian of St.

Helena (about 23° in 90 years), could be accounted for by a slow westward rotation of the internal part of. The rotation of magnetic iron in Earth's core gives rise to the planet's geomagnetic field.

Relation of the westward drift of the geomagnetic field to the rotation of the earths core book geomagnetic field, in turn, protects the planet from solar radiation, making it important for life on Earth. Without it, the planet's surface would be bombarded by charged particles streaming from the sun that would ultimately rip away Earth's.

"Edmund Halley — the comet guy — observed the geomagnetic westward drift insome years ago," Aubert said. Understanding how the Earth's core and magnetic field have changed in. An average westward drift rate ( degree/year) is obtained from the SV potential forwhich is much greater than the slow westward drift of the MG-field itself (about degree/year.

Estimated time‐fluctuations in the rate of westward drift of the geomagnetic field, –, are shown to correspond reasonably well with the unexplained systematic fluctuations in the earth's rate.

Coherent azimuthal displacements of magnetic field features at a given latitude are best visualised in time–longitude (TL) plots. In Fig. 1, we present TL plots of the radial part of the magnetic field at the CMB from CALS7K.2p at several latitudes for the time interval between BC and contours indicate radially outward magnetic field, and blue contours radially inward.

geomagnetism; geodynamo; The slow westward drift of the geomagnetic field is one of the best- and longest-known features of the historical field, for which the most likely explanation is a latitudinally dependent westward flow in the outermost outer core (1, 2).Another westward-propagating and possibly related feature is equatorial waves (), perhaps caused either by advection or instabilities.

The latitudinal dependence of the westward drift in the main geomagnetic field is examined by using the correlation analysis of moving random pattern. The study reveals the characteristics in the differential rotation of the main field. The results show that the global geomagnetic field drifts westward with an average speed of °/a during – Figure Depiction of Earth’s magnetic field between reversals (left) and during a reversal (right).

The lines represent magnetic field lines: blue where the field points toward Earth’s centre and yellow where it points away. The rotation axis of Earth is vertical, and the outline of the core. The westward drift of certain features in the geomagnetic field across Earth’s surface at a few tenths of a degree per year has long been used to suggest westward drift of Earth’s magnetizedTo the extent that the field is frozen into an electrically conducting fluid outer core, west-ward drift indicates westward flow.

"The magnetic field pushes eastwards on the inner core, causing it to spin faster than the Earth, but it also pushes in the opposite direction in the liquid outer core, which creates a westward. 2 Geomagnetic field observations. Definitions Observatories Satellites Other direct observations Indirect observations.

3 Characteristics of the Earth's magnetic field. Reversals The present magnetic field Westward drift Geomagnetic jerks Crustal magnetic field Field variations at quiet times. The westward drift of magnetic anomalies evident in the secular variation should provide an important clue to the origin of the main field if only it can be interpreted.

One model explains the drift by postulating that the outer portion of the liquid core is rotating slower than the more rigid mantle above. Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in the Earth's outer core: these.

The net result is that ions tend to drift westward and electrons eastward, a contrary motion that gives rise to a westward equatorial ring current. Along with the solar wind, the interplanetary magnetic field—itself an extension of the heliomagnetic field—controls the behavior of the magnetosphere.

This might present a problem because some features of the Earth's magnetic field exhibit a retrograde (westward) drift. Their result can be explained by the strong influence of rotation in the liquid outer core, which tends to align flow vorticity parallel to the axis of rotation.

The magnetic equator is the line where the inclination is zero (the magnetic field ishorizontal).If a line is drawn parallel to the moment of the best-fitting magnetic dipole, the two positions where it intersects the Earths surface are called the North and South geomagnetic poles.

If the Earths magnetic field were perfectly dipolar, the. The Magnetic Field of the Earth Introduction Studies of the geomagnetic field have a long history, in particular because of its importance for navigation. The geomagnetic field and its variations over time are our most direct ways to study the dynamics of the core.

The variations with time of the geomagnetic field, the secular variations. Maps of the magnetic field at the core–mantle boundary for – reveal static features in the field and an absence of westward drift from much of the core–mantle boundary.

The simulated geomagnetic field, which now spans the equivalent of overyears, has an intensity, a dipole-dominated structure and a westward drift at the surface that are all similar to. The slow westward drift of the geomagnetic field is one of the best- and longest-known features of the historical field, for which the most likely explanation is a latitudinally dependent westward flow in the outermost outer core (1, 2).Another westward-propagating and possibly related feature is equatorial waves (), perhaps caused either by advection or instabilities on an equatorial westward.

East and west. Theories to explain the drift have typically focused on the dynamics of the outer core. The most popular hypothesis, Bardsley said, is that the outer core contains a gyre similar to the atmosphere's jet stream, which happens to be moving westward and is dragging Earth's magnetic field.

Fluctuation in the Length of Day and Geomagnetic Secular Variation Chapter 7. Theory of Secular Variation Core—Mantle Coupling and the Westward Drift Rigid-Sphere Model Diffusion of Toroidal Field Mechanical Couple Exerted to the Mantle Time-Dependent Core—Mantle Coupling Oscillation of the Quadrupole Field in Relation to the Northward.

Positive ions slowly drift westward, and negative ions drift eastward, giving rise to a ring current. This current reduces the magnetic field at the Earth’s surface. Some of these particles penetrate the ionosphere and collide with the atoms there.

This results in an excitation of the oxygen and nitrogen molecular electrons. The molecules get. Variations of the geomagnetic field prior to direct observations are inferred from archeo- and paleomagnetic experiments.

Seemingly unusual variations not seen in the present-day and historical field are of particular interest to constrain the full range of core dynamics.

Recently, archeomagnetic intensity spikes, characterized by very high field values that appear to be associated with rapid. Earth's magnetic field is produced by the churning of the planet's iron outer core, which produces a complex, but largely north-south magnetic field.

understood but related to the planet's. This book is unique in bridging the gap between geology and geophysics. Its integrative approach presents students and researchers in these disciplines with other methodologies as they try to understand the Earth's processes.

It runs the gamut of earth sciences, from earthquakes and seismic exploration to thermal convection and the orogenic processes.5/5(1). The Geographic North Pole is defined by the latitude 90° N and is the axis of the Earth's rotation. The Magnetic North Pole is where the Earth's magnetic field points vertically downward.

The Earth creates its own magnetic field from the electric currents created in the liquid iron-nickel core. We have obtained a solution for the velocity of westward drift from the induction equation in which an approach for main geomagnetic field was built.

Distribution functions B(r, t) entered into the induction equation have been built by the observatories' data in North America and the Europe from to   Edmund Halley showed the westward-drifting motion of the Earth's geomagnetic field in However, this is first time that scientists have been able to link the way the inner core.

The core rotates with the earth. However, the geomagnetic field rotates at a somewhat different rate than the whole earth, and the magnetic and geographic poles do not coincide.

The geomagnetic secular variation becomes noticeable on maps older than decade. There is a prominent feature in the non-dipolar part of the secular variation that. The geomagnetic pole is the location which best fits a classic dipole (its position alters little).

And then there is the North Magnetic, or dip, Pole, which is where field lines are perpendicular. Reversals of the Earth's Magnetic Field, by J. Jacobs; Relation of the westward drift of the geomagnetic field to the rotation of the earth's core by A.

Richmond; Megagauss Magnetic Field Generation, Its Application To Science And Ultra-High Pulsed-Power Technology: Proceedings of the VIIIth International Conference. Geomagnetics, branch of geophysics concerned with all aspects of the Earth’s magnetic field, including its origin, variation through time, and manifestations in the form of magnetic poles, the remanent magnetization of rocks, and local or regional magnetic latter reflect the difference between theoretical and observed magnetic intensities at points of measurement with a.

The earths core is made of a combination of liquid and solid metal. The liquid portion moves due to convection and the earths rotation. A magnetic field is directly related with moving electrical charges according to the Lorentz law.

location of the SAA is also found to drift westwards with an average drift rate of about degrees/yr. A geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged (not to be confused with geographic north and geographic south).The Earth's field has alternated between periods of normal polarity, in which the predominant direction of the field was the same as the present direction, and reverse polarity, in which it.

The biosphere depends on earth’s magnetic field, but it has been decaying rapidly for at least years. In Spacecraft Earth: A Guide for Passengers, Dr Henry Richter describes how the story of the decay of the earth’s magnetic field caught his had read the monograph by Dr Thomas Barnes in the s, and realized the implications: if the decay is true, the earth could not be.Although Edmund Halley — who also discovered the famous comet — showed the westward-drifting motion of Earth’s geomagnetic field init is the first time that scientists have been able to link the way the inner core spins to the behavior of the outer core.