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Distinctive field behavior following geomagnetic reversals
Author(s) -
Bogue Scott W.,
Paul Hilary A.
Publication year - 1993
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl02473
Subject(s) - earth's magnetic field , geology , paleomagnetism , geomagnetic reversal , lava , geophysics , field (mathematics) , dynamo theory , dipole , geomagnetic pole , dispersion (optics) , magnetic field , dynamo , seismology , volcano , physics , mathematics , quantum mechanics , pure mathematics , optics
The paleomagnetism of lava flows from Kauai (Hawaii), erupted about 4 my ago immediately following a geomagnetic reversal, reveals that the post‐transitional field had several distinctive characteristics. While the directional dispersion was identical to that displayed by stable field over the past 5 my, the post‐transitional field intensity was unusually high. In both these respects, the field at Kauai resembles the one recorded at 15 Ma by lava flows at Steens Mountain in SE Oregon. The two records also differ in an important way: the large intensity oscillations that immediately followed the Steens Mountain reversal are not apparent in the data from Kauai. These results suggest that while the stability of the newly established dipole may vary significantly from one reversal to the next, strong dipolar field and normal directional dispersion may be systematic features of the post‐transitional geodynamo. Furthermore, the results lend support to the recent suggestion that the core remains in an unusual state for many tens of kyr following a reversal.