A secular solar system resonance that disrupts the dominant cycle in Earth's orbital eccentricity (g2-g5): Implications for astrochronology

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zeebe, Richard E., Lantink, Margriet L.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911797919875072
author Zeebe, Richard E.
Lantink, Margriet L.
author_facet Zeebe, Richard E.
Lantink, Margriet L.
contents The planets' gravitational interaction causes rhythmic changes in Earth's orbital parameters (also called Milanković cycles), which have powerful applications in geology and astrochronology. For instance, the primary astronomical eccentricity cycle due to the secular frequency term (g2-g5) (~405 kyr in the recent past) utilized in deep-time analyses is dominated by Venus' and Jupiter's orbits, aka long eccentricity cycle. The widely accepted and long-held view is that (g2-g5) was practically stable in the past and may hence be used as a "metronome" to reconstruct accurate ages and chronologies. However, using state-of-the-art integrations of the solar system, we show here that (g2-g5) can become unstable over long time scales, without major changes in, or destabilization of, planetary orbits. The (g2-g5) disruption is due to the secular resonance $σ_{12}$ = (g1 - g2) + (s1 - s2), a major contributor to solar system chaos. We demonstrate that entering/exiting the $σ_{12}$ resonance is a common phenomenon on long time scales, occurring in ~40% of our solutions. During $σ_{12}$-resonance episodes, (g2-g5) is very weak or absent and Earth's orbital eccentricity and climate-forcing spectrum are unrecognizable compared to the recent past. Our results have fundamental implications for geology and astrochronology, as well as climate forcing because the paradigm that the longest Milanković cycle dominates Earth's astronomical forcing, is stable, and has a period of ~405 kyr requires revision.
format Preprint
id arxiv_https___arxiv_org_abs_2403_09332
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A secular solar system resonance that disrupts the dominant cycle in Earth's orbital eccentricity (g2-g5): Implications for astrochronology
Zeebe, Richard E.
Lantink, Margriet L.
Earth and Planetary Astrophysics
Geophysics
The planets' gravitational interaction causes rhythmic changes in Earth's orbital parameters (also called Milanković cycles), which have powerful applications in geology and astrochronology. For instance, the primary astronomical eccentricity cycle due to the secular frequency term (g2-g5) (~405 kyr in the recent past) utilized in deep-time analyses is dominated by Venus' and Jupiter's orbits, aka long eccentricity cycle. The widely accepted and long-held view is that (g2-g5) was practically stable in the past and may hence be used as a "metronome" to reconstruct accurate ages and chronologies. However, using state-of-the-art integrations of the solar system, we show here that (g2-g5) can become unstable over long time scales, without major changes in, or destabilization of, planetary orbits. The (g2-g5) disruption is due to the secular resonance $σ_{12}$ = (g1 - g2) + (s1 - s2), a major contributor to solar system chaos. We demonstrate that entering/exiting the $σ_{12}$ resonance is a common phenomenon on long time scales, occurring in ~40% of our solutions. During $σ_{12}$-resonance episodes, (g2-g5) is very weak or absent and Earth's orbital eccentricity and climate-forcing spectrum are unrecognizable compared to the recent past. Our results have fundamental implications for geology and astrochronology, as well as climate forcing because the paradigm that the longest Milanković cycle dominates Earth's astronomical forcing, is stable, and has a period of ~405 kyr requires revision.
title A secular solar system resonance that disrupts the dominant cycle in Earth's orbital eccentricity (g2-g5): Implications for astrochronology
topic Earth and Planetary Astrophysics
Geophysics
url https://arxiv.org/abs/2403.09332