Open AccessCould the Mw = 9.3 Sumatra earthquake trigger a geomagnetic jerk?
Author(s) -
Florindo Fabio,
De Michelis Paola,
Piersanti Antonio,
Boschi Enzo
Publication year - 2005
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2005eo120004
Subject(s) - earth's magnetic field , jerk , geomagnetic secular variation , secular variation , geology , geodesy , geophysics , ionospheric dynamo region , geomagnetic reversal , magnetic field , physics , geomagnetic storm , classical mechanics , acceleration , quantum mechanics
The magnetic field observed at the Earth's surface is not a stationary feature. It is characterized by time variations ranging from milliseconds (micropulsations) to millions of years (the time interval between field reversals). Time variations with periods of a year or longer are related to Earth's outer core sources, whereas for shorter timescales an external origin is invoked (i.e.,solar activity). One of the most interesting time variations of the geomagnetic field is represented by the “geomagnetic jerk.” It is idealized as a rapid change in the slope of the secular variation, defined as the first derivative of the geomagnetic field. This means that the secular variation roughly appears as a series of straightline segments separated by geomagnetic jerks.