alodfromk: Compute Earth-Moon distance and length of day from precession...

In astrochron: A Computational Tool for Astrochronology

Compute Earth-Moon distance and length of day from precession frequency

Description

Compute Earth-Moon distance (a; Earth radii) and length of day (LOD; hours), and their uncertainties, from precession frequency (k; arcsec/yr).

Usage

alodfromk(k,sdevk,genplot=TRUE,verbose=TRUE)

Arguments

k	precession frequency, arcsec/yr
sdevk	standard deviation of precession frequency, arcsec/yr
genplot	generate summary plots (T or F)
verbose	verbose output (T or F)

Details

Compute a (Earth radii), LOD (hrs) and their uncertainties for a given value of k (arcsec/yr) and its uncertainty. Calculations are based on the original equations of Walker et al. (1986), with adjusted constants Kconst and Aconst as in Malinverno and Meyers (2024).

References

Walker, J.C.G., Zahnle, K.J., 1986, Lunar nodal tide and distance to the Moon during the Precambrian: Nature 320, 600-602.

Malinverno, A. and Meyers, S.R., 2024, Bayesian estimation of past astronomical frequencies, lunar distance, and length of day from sediment cycles: Geochemistry, Geophysics, Geosystems, 25, e2023GC011176.

Examples

# Example using results from timeOptB analysis of Xiamaling Cu/Al data (see timeOptB help page)
alodfromk(k=87.66382,sdevk=1.44810)

astrochron documentation built on July 17, 2026, 9:06 a.m.