Factors Influencing the Earth's Magnetic Field Evolution

TL;DR

This study explores how internal Earth processes and changes in Earth's rotation influence the ancient geomagnetic field's intensity and polarity reversals over millions of years.

Contribution

It links paleointensity and inversion frequency variations to mantle plumes and Earth's rotational evolution, providing new insights into geomagnetic field dynamics.

Findings

Large basalt effusions correlate with 30-40% paleointensity changes.

Paleointensity variations occur over 10-20 million-year intervals.

Geomagnetic properties vary with Earth-Moon distance cycles (~200 Ma).

Abstract

The relationship between the behavior of an ancient geomagnetic field characteristics (paleointensity and frequency of inversions) and cyclic recurrence of endogenic and cosmogeneous processes which are conceivably connected with radial mantle heat transmission and the Earth rotation speed has been studied. It is shown that endogenic processes affect the behavior of the paleointensity and frequency of inversions. Large basalt effusions identified with plumes are accompanied by the changes in paleointensity (by 30-40)% and the frequency of inversions. Characteristic time intervals of paleointensity variations caused by the formation of plumes makes up 10-20 Ma. The paleointensity varies (by 15-30)% according to phases of the riftogenesis activization and tension - compression cycles. The dependence of geomagnetic field behavior on changes of the Earth rotation speed which occurred as a result of the Earth - Moon - Sun system evolution has been analyzed. Thus, in accordance with phases of the Earth - Moon distance changes (periodicity about 200 Ma) average values of the paleointensity varied by a factor of two. Besides, the frequency of inversions, asymmetry of polarity and features of paleointensity variations changed too.