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Related papers: Geomagnetic spikes on the core-mantle boundary

200 papers

We have found that about two months after creating a new radiation belt in the inner magnetosphere due to a geomagnetic storm, an increasing seismic activity may occur near the magnetic field lines' footprint of a newly created radiation…

Geophysics · Physics 2022-02-22 Dimitar Ouzounov , Galina Khachikyan

We derive the minimal seed magnetic field which unavoidably arises in the radiation and matter eras, prior to recombination, by the rotational velocity of ions and electrons, gravitationally induced by the non-linear evolution of primordial…

Astrophysics · Physics 2009-11-10 S. Matarrese , S. Mollerach , A. Notari , A. Riotto

The geomagnetic field has undergone hundreds of polarity reversals over Earth's history, at a variable pace. In numerical models of Earth's core dynamics, reversals occur with increasing frequency when the convective forcing is increased…

Geophysics · Physics 2025-05-09 Julien Aubert , Maylis Landeau , Alexandre Fournier , Thomas Gastine

The present paper summarizes results of the studies on the intensity of geomagnetic field in the (167 - 23) Ma interval by sedimentary rocks of the Russian Plate and adjacent territories. The joint analysis of the data paleointensity…

Geophysics · Physics 2014-10-03 A. Yu. Kurazhkovskii , N. A. Kurazhkovskaya , B. I. Klain

Evidence of fast variations in the Earth's core field are seen both in magnetic observatory and satellite records. We present here how they have been identified at the Earth's surface from ground-based observatory records and how their…

Geophysics · Physics 2022-01-17 V. Lesur , N. Gillet , M. D. Hammer , M. Mandea

Galaxy mergers are expected to play a central role for the evolution of galaxies, and may have a strong impact on their magnetic fields. We present the first grid-based 3D magneto-hydrodynamical simulations investigating the evolution of…

Astrophysics of Galaxies · Physics 2016-09-28 Kai Rodenbeck , Dominik R. G. Schleicher

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-16 Dai G. Yamazaki , Toshitaka Kajino , Grant J. Mathew , Kiyotomo Ichiki

A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Tanmay Vachaspati

Geomagnetic secular acceleration is a unique window on the dynamics taking place in Earth's core. In this study, the behaviours of the secular acceleration and underlying core dynamics are examined in new numerical simulations of the…

Geophysics · Physics 2018-05-24 Julien Aubert

(abridged) A detailed examination of the evolution of stochastic magnetic fields between high cosmic temperatures and the present epoch is presented. A simple analytical model matching the results of the 3D MHD simulations allows for the…

Astrophysics · Physics 2009-11-10 Robi Banerjee , Karsten Jedamzik

Within the fluid iron cores of terrestrial planets, convection and the resulting generation of global magnetic fields are controlled by the overlying rocky mantle. The thermal structure of the lower mantle determines how much heat is…

Geophysics · Physics 2015-11-05 Wieland Dietrich , Johannes Wicht , Kumiko Hori

We consider the possibility that cosmic magnetic field, instead of being uniformly distributed, is strongly correlated with the large scale structure of the universe. Then, the observed rotational measure of extra-galactic radio sources…

Astrophysics · Physics 2011-07-19 Dongsu Ryu , Hyesung Kang , Peter L. Biermann

We assess the likelihood and geochemical consequences of the presence of nuclear georeactors in the core mantle boundary region (CMB) between Earths silicate mantle and metallic core. Current geochemical models for the Earths interior…

Geophysics · Physics 2008-05-07 R. J. de Meijer , W. van Westrenen

Primordial magnetic fields possibly generated in the very early universe are one of the candidates for the origin of magnetic fields observed in many galaxies and galaxy clusters. After recombination, the dissipation process of the…

Astrophysics · Physics 2009-11-11 Hiroyuki Tashiro , Naoshi Sugiyama

The amplitude of the magnetic field surrounding the Galactic Centre (GC) on large scales (> 100 pc) has been uncertain by two orders of magnitude for several decades: different analyses report fields as weak as ~6 microG on the one hand and…

Astrophysics of Galaxies · Physics 2010-01-27 Roland M. Crocker

We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the…

Solar and Stellar Astrophysics · Physics 2013-11-19 Petri J. Käpylä , Maarit J. Mantere , Axel Brandenburg

The mechanism by which the Earth's magnetic field is generated is thought to be thermal convection in the metallic liquid iron core. Computational considerations previously restricted most numerical simulations to a regime where the…

Geophysics · Physics 2017-01-17 Andrey Sheyko , Christopher Finlay , Jean Favre , Andrew Jackson

The results of paleointensity determinations of the geomagnetic field, which are obtained by sedimentary rocks in the Middle Jurassic - Neogene (167-12) Ma, are summarized. It was found that in the interval (167-67) Ma (Middle Jurassic -…

Geophysics · Physics 2017-07-28 A. Yu. Kurazhkovskii , N. A. Kurazhkovskaya , B. I. Klain

The Earth acts as a gigantic heat engine driven by decay of radiogenic isotopes and slow cooling, which gives rise to plate tectonics, volcanoes, and mountain building. Another key product is the geomagnetic field, generated in the liquid…

Geophysics · Physics 2015-06-04 Monica Pozzo , Chris Davies , David Gubbins , Dario Alfè

The presence of low viscosity layers in the mantle is supported by line of geological and geophysical observations. Recent high pressure and temperature investigations indicated that partial carbonate melt should exist at the bottom of the…

General Physics · Physics 2007-09-11 Jozsef Garai