NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
On the geomagnetic jerk of 1969Courtillot et al. (1978) have first reported a sudden change in the slope of the first time derivatives of the geomagnetic field components which occurred around 1970. It was found that the change took place in a large part of the northern hemisphere. Malin and Hodder (1982) reported on studies which were conducted to determine whether this 1970 step change in the second time derivative of the geomagnetic field components, which they termed a geomagnetic 'jerk', was of internal or external origin. It was concluded that internal sources can give rise to changes in secular variation on time scales as short as one or two years and that these were the major factor in the geomagnetic jerk which occurred around 1970. The present paper provides new supporting evidence for the existence of a worldwide geomagnetic jerk, its (average) time of occurrence, and its internal nature. New estimates are given of the spherical harmonic coefficients of the jerk and of the pre-1969 and post-1969 secular acceleration.
Document ID
19850052418
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Mcleod, M. G.
(BTS, Inc., Seabrook, MD; California, University Los Angeles, CA, United States)
Date Acquired
August 12, 2013
Publication Date
May 10, 1985
Publication Information
Publication: Journal of Geophysical Research
Volume: 90
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
85A34569
Funding Number(s)
CONTRACT_GRANT: NGL-05-007-004
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available