Results 21 to 30 of about 130 (107)
Worldwide wavelet analysis of geomagnetic jerks [PDF]
Journal of Geophysical Research: Solid Earth, 1996 Following an earlier study which gives the principles of the method and an example of application to the eastern component of the magnetic field in the European region [Alexandrescu et al., 1995], detection and characterization of geomagnetic jerks using wavelet analysis is generalized to any horizontal component of the field and to a worldwide ...
Alexandrescu, Mioara +4 more
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Earth, Planets and Space, 2021 We present the GFZ candidate field models for the $$13{\mathrm{th}}$$ 13 th Generation International Geomagnetic Reference Field (IGRF-13). These candidates were derived from the Mag.num.IGRF13 geomagnetic core field model, which is constrained by Swarm
M. Rother +5 more
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Results of the Helsinki magnetic observatory 1844-1912 [PDF]
Annales Geophysicae, 2004 The geomagnetic field declination (D) and horizontal component (H) were observed visually at the Helsinki magnetic observatory between 1844–1912. About 2.0 million single observations of the magnetic components are available.
H. Nevanlinna
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A global analysis of the 1991 geomagnetic jerk [PDF]
Geophysical Journal International, 2000 Summary A recent examination of the geomagnetic annual mean values for the European magnetic observatories has shown the existence of a sudden change in the secular acceleration in about 1991 (Cafarella & Meloni 1995; Macmillan 1996). Using first differences of the Y (east geomagnetic field component) mean values from 74 observatories, the worldwide
De Michelis, P. +2 more
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Strong earthquakes and geomagnetic jerks: a cause-effect relationship?
Annals of Geophysics, 1995 Secular variation of the geomagnetic field observed at the Earth's surface has been found to undergo impulsive accelerations Gerks) lasting less than a few years. In this paper the relations between jerks and the occurrence of strong earthquakes (Ms ?
L. Alfonsi, F. Florindo
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Dizhen xuebao, 2019 为探索地磁长期变化中地磁急变事件的识别方法，分析地磁急变的特征，本文基于多个地磁台站子夜均值数据，利用线性拟合方法计算了地磁场X，Y和Z三个分量的年变率，对近年来发生的地磁急变事件进行了识别和分析。结果显示：Y分量能对分析时段内已报道的地磁急变事件进行很好的识别，其中1999年的地磁急变事件，在我国区域内发生的时间可能为1998年，此外2017年可能存在一个新的地磁急变事件；Z分量年变率整体变化平缓，2001年和2013年前后发生两次显著的地磁年变率变化 ...
Yufei He +4 more
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Local time features of geomagnetic jerks [PDF]
Earth, Planets and Space, 2014 The geomagnetic jerk amplitudes, which are defined as abruptness of changes in the trends of geomagnetic time series, are investigated with geomagnetic monthly means computed from hourly mean values at each local time. A statistical time series model in which the trend component is expressed by a second order spline function with variable knots is ...
Nagao, Hiromichi +4 more
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Geomagnetic jerks in the polar regions
Geophysical Research Letters, 2009 The occurrence of geomagnetic jerks over the Arctic and Antarctic regions is here investigated. Maps of geomagnetic secular acceleration over the polar regions are produced from the CM4 and CHAOS models and the occurrence of geomagnetic jerks is associated with jumps in secular acceleration.
R. Tozzi, P. De Michelis, A. Meloni
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Evidence for geomagnetic jerks in comprehensive models [PDF]
Earth, Planets and Space, 2005 Abstract The rate of secular variation occasionally undergoes a sudden, sharp change, called a geomagnetic jerk. Such jerks have been detected in geomagnetic time series, centered—over the last four decades—around 1971, 1980, 1991, and 1999; others have been inferred from historical records. The geomagnetic jerks represent a reorganization of
Chambodut, A., Mandea, M.
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Geomagnetic jerks and seismic activity
Annals of Geophysics, 1996 By means of a Monte Carlo simulation, we explored the extent to which large earthquakes may induce fluctuations on the secular variation of the Earth's magnetic field. We speculate that the energy released by large earthquakes may perturb the dynamical interaction between the outer core and the lower mantle, and consequently give rise to rapid ...
F. Florindo +4 more
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