The Resonant Tidal Evolution of the Earth-Moon Distance

TL;DR

This paper introduces a physical model of tidal evolution that reconciles geological data and lunar recession rates, revealing multiple resonance crossings that caused rapid changes in Earth's rotation and the Moon's orbit.

Contribution

It presents a novel tidal evolution model that accounts for resonance crossings, aligning geological proxies with observed lunar recession and Earth's rotational history.

Findings

Model fits geological proxies for Earth-Moon history

Reveals multiple resonance crossings in tidal evolution

Explains rapid variations in Earth's day length and obliquity

Abstract

Due to tidal interactions in the Earth-Moon system, the spin of the Earth slows down and the Moon drifts away. This recession of the Moon is now measured with great precision, but it has been realized, more than fifty years ago, that simple tidal models extrapolated back in time lead to an age of the Moon that is by far incompatible with the geochronological and geochemical evidence. In order to evade this problem, more elaborate models have been proposed, taking into account the oceanic tidal dissipation. However, these models did not fit both the estimated lunar age and the present rate of lunar recession simultaneously. Here we present a physical model that reconciles these two constraints and yields a unique solution of the tidal history. This solution fits well the available geological proxies for the history of the Earth-Moon system and consolidates the cyclostratigraphic method. The resulting evolution involves multiple crossings of resonances in the oceanic dissipation that are associated with significant and rapid variations in the lunar orbital distance, the Earth's length of the day, and the Earth's obliquity.