magnetic reversal


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magnetic reversal

[mag′ned·ik ri′vər·səl]
(geophysics)
A reversal of the polarity of the earth's magnetic field that has occurred at about one-million-year intervals.
References in periodicals archive ?
We don't know where or how that magnetic reversal boundary forms in the lower crust.
For this simulator, the research team created a polycrystalline model in which 27 neodymium-magnet crystals were magnetically bonded, and simulated the process of magnetic reversal while varying the strength of the magnetic couplings between the crystals.
Experts said that the sun's magnetic reversal began in 1997 and was predicted to end in 2013.
At sea, scientists collected magnetic data from sensors towed from ships and found remarkable magnetic patterns in seafloor rocks that were subsequently correlated with the magnetic reversal "clock" established in terrestrial rocks.
In experiments performed on the particle accelerator BESSY II of Helmholtz-Zentrum Berlin, Dutch researchers have achieved ultrafast magnetic reversal of an atom's magnetic moment.
There's no evidence that a magnetic reversal has ever caused a large-scale extinction, and our ancestors, Homo erectus, breezed through several reversals without any evidence of a population decline.
By prying loose magnetic-field loops anchored to the visible solar surface, coronal mass ejections may sweep the surface clean of old magnetic fields and prepare the sun for its magnetic reversal.
His research interests include the magnetic polarity time scale for pre-oceanic periods and changes in magnetic reversal frequency since the Paleozoic Era.
These improved stratigraphies were provided for the North Atlantic by the scientists of Leg 81, and by the mid 1980s it became dear that Northern Hemisphere ice rafting began in both the North Atlantic and North Pacific almost exactly at the time of the Matuyama-Gauss magnetic reversal, recently dated at 2.
Scientists regard Steens Mountain as the best record of a magnetic reversal because the volcano spewed out 56 separate flows during that episode.
Every comet shower need not produce a magnetic reversal.
She then considered magnetic reversals on the Earth, as we are about overdue for the next one.

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