Publication Date:
2017-04-04
Description:
A recent examination of the geomagnetic element annual mean values fbr the European magnetic observatories, has shown the existence of a sudden change in the secular acceleration at about 1991. In this work the space time character of the 1991 impulse is investigated and its worldwide character
is evidenced; an evaluation of the amplitude spatial distribution is given for the Y component, analysing data relative to
74 magnetic observatories. The external effects were removed from the annual mean data and successively the Y secular
variation has been evaluated from the corrected annual means.
Moreover the worldwide character of the intensity of the step in the second time derivative is compared with the character of
the previous well known jerk events of 1969 and 1978.
Description:
Published
Description:
377-380
Description:
3.4. Geomagnetismo
Description:
JCR Journal
Description:
reserved
Keywords:
Geomagnetic field
;
Secular variation
;
Geomagnetic jerk
;
04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
