Results 61 to 70 of about 416 (175)

Reversals in the six-jet Geodynamo model

E3S Web of Conferences, 2016
We describe a large-scale geodynamo model based on hypothesis about 6-cells convection in the Earth’s core. This hypothesis suggests indirect data of inhomogeneities in the density of the Earth?s core.
Vodinchar Gleb, Feshchenko Lyubov
doaj   +1 more source

Evidence for Missing Geomagnetic Reversals From Geomagnetic Reversal Frequency Model Using Adaptive Kernel Density Estimation

Geophysical Research Letters, Volume 53, Issue 4, 28 February 2026.
Abstract The existence of missing geomagnetic reversals has been proposed, with potential for new magnetostratigraphic age controls. We estimate geomagnetic reversal frequency from 0 to 155 Ma using adaptive‐bandwidth kernel density estimation (AKDE) to evaluate data sparseness and to assess how reversal frequency changes when recently identified ...
Yutaka Yoshimura, Masakazu Fujii, Hideitsu Hino, Shotaro Akaho, Satoshi Kuriki, Osamu Ishizuka, Toshitsugu Yamazaki, Hyeon‐Seon Ahn, Tesfaye Kidane, Yuhji Yamamoto, Yo‐ichiro Otofuji   +10 more
wiley   +1 more source

Self‐Consistent Models of Earth's Mantle and Core From Long‐Period Seismic and Tidal Constraints

Journal of Geophysical Research: Solid Earth, Volume 131, Issue 2, February 2026.
Abstract Here we illustrate the use of parameterized models to address fundamental questions about Earth's mantle and core structure. For this, we invert a large set of normal‐mode center frequencies and quality (attenuation) factors, along with astronomic‐geodetic data, for the radial anelastic seismic structure of the Earth.
F. D. Munch, J. Kemper, A. Khan, G. Helffrich, D. Giardini   +4 more
wiley   +1 more source

Superdipole Geomagnetic Field in the Past

Russian Journal of Earth Sciences
According to the model of the Earth’s cooling, before the solid core origin, there was a sub-adiabatic layer at the core-mantle boundary several hundred kilometers thick. In this layer magnetic field generation was suppressed.
Reshetnyak Maxim
doaj   +1 more source

Reduced Geomagnetic Shielding During the Laschamps Excursion and Its Impact on Cosmic‐Ray‐Induced Atmospheric Radiation

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract The Laschamps geomagnetic excursion (≈41,000 years BP) was a period of significant weakening and incomplete reversal of the Earth's magnetic field. The weakening substantially reduced geomagnetic shielding against cosmic rays (CRs), which contribute to phenomena at Earth, such as cosmogenic isotope production, and atmospheric ionisation and ...
N. Larsen, I. Usoskin, A. Mishev, S. Koldobskiy, P. Väisänen   +4 more
wiley   +1 more source

Estimates of Quantities in a Hall Effect Geodynamo Theory

Advances in Electrical and Electronic Engineering, 2008
Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect.
Annraoi M de Paor
doaj  

A Global Paleosecular Variation Database for the Paleogene: Stationary Secular Variation Behavior Since the Triassic?

Geochemistry, Geophysics, Geosystems
Paleosecular variation analysis is a primary tool for characterizing ancient geomagnetic behavior and its evolution through time. This study presents a new high‐quality directional data set, paleosecular variation of the Paleogene (PSVP), with and ...
Y. A. Engbers, D. Thallner, R. K. Bono, C. J. Sprain, M. J. Murray, K. Bristol, B. Handford, T. Torsvik, A. J. Biggin   +8 more
doaj   +1 more source

Reassessment of electromagnetic core-mantle coupling and its implications to the Earth's decadal polar motion

Geodesy and Geodynamics, 2019
The observed Earth's polar motion on decadal time scales has long been conjectured to be excited by the exchange of equatorial angular momentum between the solid mantle and the fluid outer core, via the mechanism of electromagnetic (EM) core-mantle ...
Weijia Kuang, Benjamin F. Chao, Jianli Chen   +2 more
doaj   +1 more source

The inner core and the geodynamo

Comptes Rendus. Géoscience, 2003
Using energy and entropy constraints applicable to the Earth's core, the heat flow at the core–mantle boundary (CMB) needed to sustain a given total dissipation in the core can be computed. Reasonable estimates for the present Joule dissipation in the core gives a present heat flow of 6 to 10 TW at the CMB.
Stéphane Labrosse, Mélina Macouin
openaire   +1 more source

Reversals and Large-Scale Variations of the Geomagnetic Field: Similarities and Differences

Russian Journal of Earth Sciences
It is shown that during reversals in geodynamo models the minimum amplitudes of the dipole, quadrupole and octupole coincide. Since the characteristic time of the reversal is close to the oscillations of the large-scale geomagnetic field, a similar ...
Reshetnyak Maxim
doaj   +1 more source