Time-correlation-based regression of the geomagnetic field from archeological and sediment records

Alternating intervals of normal and reversed polarity are revealed in the sections of two Permian–Triassic trap intrusions of the Ergalakhsky complex, Norilsk region. The near-contact zones of the intrusions are magnetized reversely, whereas magnetization in the central zones has normal polarity. The arguments are presented that this change in the polarity along the intrusions section is not due to the postmagmatic remagnetization or self-reversal of remanence but marks the reversal of the geomagnetic field that occurred during the emplacement of the intrusive bodies. Highly accurate age determination for the Ergalakhsky intrusions – the oldest intrusive trap complex in the Norilsk region – is vital for time correlation of the initial stage of magmatic activity. According to the paleomagnetic data, the studied sills intruded directly at the Permian–Triassic boundary at the very end of the Ivakinsky stage. The existing estimates for the durations of the reversals indicate that the cooling of the intrusions could last a few thousand years. In the future, the examined sills of the Ergalakhsky complex can be used as a unique object for exploring the structure of the geomagnetic field during the reversals, for reconstructing the thermal history of intrusions’ cooling, and as a reference for estimating the total duration of trap magmatism.

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Global evolution and dynamics of the geomagnetic field in the 15–70 kyr period based on selected paleomagnetic sediment records

Journal of Geophysical Research Solid Earth ◽

10.1029/2021jb022681 ◽

2021 ◽

Author(s):

Sanja Panovska ◽

Monika Korte ◽

Jiabo Liu ◽

Norbert Nowaczyk

Keyword(s):

Geomagnetic Field ◽

Global Evolution ◽

Sediment Records

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Deep-sea sediment records of the Laschamp geomagnetic field excursion (∼41,000 calendar years before present)

Journal of Geophysical Research Atmospheres ◽

10.1029/2003jb002943 ◽

2005 ◽

Vol 110 (B4) ◽

Cited By ~ 56

Author(s):

Steve P. Lund ◽

Martha Schwartz ◽

Lloyd Keigwin ◽

Thomas Johnson

Keyword(s):

Deep Sea ◽

Geomagnetic Field ◽

Before Present ◽

Deep Sea Sediment ◽

Sediment Records ◽

Field Excursion

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MONOFRACTAL AND MULTIFRACTAL ANALYSIS IN SHORT - TERM TIME DYNAMICS OF ULF GEOMAGNETIC FIELD MEASURED IN CRETE, GREECE

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16473 ◽

2004 ◽

Vol 36 (3) ◽

pp. 1298 ◽

Cited By ~ 1

Author(s):

F. Vallianatos ◽

J. P. Makris ◽

V. Saltas ◽

L. Telesca ◽

V. Lapenna

Keyword(s):

Geomagnetic Field ◽

Low Frequency ◽

Multifractal Spectrum ◽

Time Correlation ◽

Short Term ◽

Time Dynamics ◽

Power Spectral ◽

Dynamical Fluctuations ◽

Scale Properties

In this work, a monofractal and multifractal characterization of the short-term time dynamical fluctuations of the ultra low frequency (ULF) geomagnetic field, measured by one station installed in Creete, Greece, has been carried out. Time scale properties of the three ULF geomagnetic components, two horizontal (x, y) and one vertical (z) have been analyzed through the power spectral density, Higuchi method and Hurst R/S analysis. Results point out the presence of fractal features expressing long-range time correlation with scaling coefficients, which are the clue of persistent mechanism. Using a set of multifractal parameters, defined from the shape of the multifractal spectrum, it has been observed that the degree of multifractality, that characterizes the original signals, is "weaker" if compared to the residual signals, obtained from the original ones after removing the four observed periodicities (24-, 12-, 8- and 6-h periodicties). Furthermore the horizontal χ and y components have revealed to be less multifractal than the vertical z-component.

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