MCADAM: A continuous paleomagnetic dipole moment model for at least 3.7
billion years
Abstract
Understanding the evolution of Earth’s magnetic field can provide
insights into core processes and can constrain plate tectonics and
atmospheric shielding. The absolute paleointensity database PINT
provides a curated repository of site mean, (i.e., cooling unit),
estimates of the strength of the magnetic field. We present a minor
update to the PINT database to version 8.1.0 by adding 248 records from
31 studies. The PINT database is used to define a continuous model of
the dipole field, using an approach combining non-parametric and Monte
Carlo resampling termed MCADAM. Three dipole field strength models
spanning 50 ka to 3.7-4.2 Ga (MCADAM.1a-c) are presented, reflecting
three tiers of increasingly more stringent data selection. The MCADAM
models allow for the estimation of the magnetic standoff distance,
constraining the shielding of Earth’s atmosphere against solar wind
erosion provided by the geodynamo.