학술논문

The Effect of Stress on Paleomagnetic Signals: A Micromagnetic Study of Magnetite's Single‐Vortex Response
Document Type
article
Source
Geophysical Research Letters, Vol 51, Iss 2, Pp n/a-n/a (2024)
Subject
mineral magnetism
paleomagnetism
stress
single‐vortex
single domain
Geophysics. Cosmic physics
QC801-809
Language
English
ISSN
1944-8007
0094-8276
Abstract
Abstract In this study we use micromagnetic modeling to show that the magnetizations of magnetically single‐vortex particles rotate toward the stress axis on the application of a differential compression stress. This is the exact opposite response to magnetically single‐domain particles, which previously provided the theoretical underpinning of the effect of stress on the magnetic signals of rocks. We show that the magnetization directions of single‐vortex and equant single‐domain particles are altered by much lower stresses than previously predicted, c.f., 100 versus 1,000 MPa; where a change in magnetization is defined as a rotation of >3° after the removal of stress. The magnetization intensity of assemblages also drops by ∼20%–30% on the application and removal of stress of ∼100 MPa. Given that single‐vortex particles are now thought to dominate the magnetization of most rocks, future studies should account for paleomagnetic directional uncertainties and potential underestimation of the ancient magnetic field intensity.